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2014 NEC Instructors Manual and Student Worksheets – Level 2 1

2014

ELECTRICAL INSPECTOR

INSTRUCTORS’ MANUAL

LEVEL II

NC Code Officials Qualification Board

322 Chapanoke Road

Raleigh, NC 27603


ARTICLE TITLE PAGE TM

100 DEFINITIONS 70-27 4 110 REQUIREMENTS FOR ELECTRICAL INSTALLATIONS 70-36 7 220 BRANCH CIRCUIT, FEEDER AND SERVICE CALCULATIONS 70-66 11 225 OUTSIDE BRANCH CIRCUITS AND FEEDERS 70-76 17 240 OVERCURRENT PROTECTION 70-94 22 250 GROUNDING AND BONDING 70-106 25 310 CONDUCTORS FOR GENERAL WIRING 70-154 28 320 ARMORED CABLE : TYPE AC 70-193 33 324 FLAT CONDUCTOR CABLE: TYPE FCC 70-196 36 332 MINERAL-INSULATED, METAL-SHEATHED CABLE: TYPE MI 70-202 39 360 FLEXIBLE METALLIC TUBING: TYPE FMT 70-226 42

362 ELECTRICAL NONMETALLIC TUBING: TYPE ENT 70-227 45 368 BUSWAYS 70-231 48 370 CABLEBUS 70-234 51 372 CELLULAR CONCRETE FLOOR RACEWAYS 70-235 54 374 CELLULAR METAL FLOOR RACEWAYS 70-236 57 376 METAL WIREWAYS 70-237 60 378 NONMETALLIC WIREWAYS 70-239 60 382 NONMETALLIC EXTENSIONS 70-240 63 390 UNDERFLOOR RACEWAYS 70-246 66 396 MESSENGER-SUPPORTED WIRING 70-258 70 398 OPEN WIRING ON INSULATORS 70-259 72 424 FIXED ELECTRIC SPACE-HEATING EQUIPMENT 70-308 75 426 FIXED OUTDOOR ELECTRIC DEICING AND

SNOW-MELTING EQUIPMENT 70-317 85

430 MOTORS, MOTOR CIRCUITS, AND CONTROLLERS 70-323 90 450 TRANSFORMERS AND TRANSFORMER VAULTS 70-360 96 460 CAPACITORS 70-370 99 480 STORAGE BATTERIES 70-372 102 510 HAZARDOUS (CLASSIFIED) LOCATIONS —SPECIFIC 70-437 105 511 COMMERCIAL GARAGES, REPAIR AND STORAGE 70-437 108

520 THEATERS, AUDIENCE AREAS OF MOTION PICTURE AND TELEVISION STUDIOS, PERFORMANCE AREAS, AND SIMILAR LOCATIONS

70-482 111

522 CONTROL SYSTEMS FOR PERMANENT AMUSEMENT ATTRACTIONS

70-491 116 525 CARNIVALS, CIRCUSES, FAIRS, AND SIMILAR

EVENTS 70-493 119

540 MOTION PICTURE PROJECTION ROOMS 70-499 122 555 MARINAS AND BOATYARDS 70-536 126

604 MANUFACTURED WIRING SYSTEMS 70-549 131

620 ELEVATORS, DUMBWAITERS, ESCALATORS, MOVING WALKS, PLATFORM LIFTS, AND STAIRWAY CHAIRLIFTS

70-557 134

625 ELECTRIC VEHICLE CHARGING SYSTEM 70-567 139

630 ELECTRIC WELDERS 70-577 142

LEVEL II

TABLE OF CONTENTS BY ARTICLES


640 AUDIO SIGNAL PROCESSING, AMPLIFICATION,

AND REPRODUCTION EQUIPMENT 70-579 154

645 INFORMATION TECHNOLOGY EQUIPMENT 70-584 148

650 PIPE ORGANS 70-593 151 670 INDUSTRIAL MACHINERY 70-601 154 675 ELECTRICALLY DRIVEN OR CONTROLLED

IRRIGATION MACHINES 70-602 158

685 INTEGRATED ELECTRICAL SYSTEMS 70-622 162

695 FIRE PUMPS 70-646 165

700 EMERGENCY SYSTEMS 70-652 169

701 LEGALLY REQUIRED STANDBY SYSTEMS 70-657 175 702 OPTIONAL STANDBY SYSTEMS 70-661 179

708 CRITICAL OPERATIONS POWER SYSTEMS (COPS) 70-667 182 720 CIRCUITS AND EQUIPMENT OPERATING AT LESS THAN 50 VOLTS 70-672 185

725 CLASS 1, CLASS 2 AND CLASS 3 REMOTE-CONTROL , SIGNALING, AND POWER-LIMITED CIRCUITS

70-672 188

727 INSTRUMENTATION TRAY CABLE: TYPE ITC 70-685 192 760 FIRE ALARM SYSTEMS 70-688 195 770 OPTICAL FIBER CABLES AND RACEWAYS 70-669 200 800 COMMUNICATIONS CIRCUITS 70-709 203 810 RADIO AND TELEVISION EQUIPMENT 70-725 206

820 COMMUNITY ANTENNA TELEVISION AND RADIO DISTRIBUTION SYSTEMS

70-729 209

THE PAGE NUMBER LISTED ABOVE CORRESPONDS TO THE ARTICLE LOCATION IN THE NORTH CAROLINA

ELECTRIC CODE BOOK (THE NEC 2014). THE “TM” NUMBERS TO THE RIGHT OF THE ARTICLE NUMBERS

CORRESPONDS TO THE PAGE NUMBERS IN THE TRAINING MANUAL FOR THE STARTING PAGE FOR EACH

ARTICLE LISTED.


DEFINITIONS

ARTICLE 100

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with definitions essential to

the proper use of the National Electrical Code.

INTRODUCTION:

This lesson should give the inspector a clear definition of terms used in the National

Electrical Code. The definitions included in Article 100 are terms used in two or more

articles of the Code. Definitions specific to only one article are given in that article.

PRESENTING THE LESSON:

The current edition of the National Electrical Code is used. The instructor should lead a

class discussion on definitions, giving illustrations of the definitions.

Example:

Switches:

Transfer switch - a device for transferring one or more load conductor connections from

one power source to another.

(Show examples with slides or on chalkboard in class, using actual materials if available).

APPLICATION:

If time will allow, have the students answer the questions on the worksheet.

CHECKING AND FOLLOW-UP

If time will allow, correct the worksheets and discuss the results.


DEFINITIONS

ARTICLE 100

Level II

WORKSHEET

1. Which of the following is a device, group of devices, or other means whereby the

conductors of a circuit can be disconnected from their source of supply?

a. A thermal overload device.

b. A disconnecting means.

c. A fuse.

d. A switch.

2. Which of the following best describes a multifamily dwelling?

a. A building that contains dwelling units.

b. A building that contains two dwelling units.

c. A building that contains two or more dwelling units.

d. A building that contains three or more dwelling units.

3. A continuous load is a load expected to exist for which of the following?

a. 1 hour or more

b. 2 hours or more

c. 3 hours or more

d. 4 hours or more


DEFINITIONS

ARTICLE 100

Level II

ANSWER KEY

1. b. a disconnecting means 100

2. d. 3 or more - see dwelling multi-family 100

3. c - 3 hours or more 100


REQUIREMENTS FOR ELECTRICAL INSTALLATIONS

ARTICLE 110

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the general requirements

of the National Electrical Code for electrical installation.

INTRODUCTION:

This Article contains general requirements for all electrical installations including listing of

equipment, access and working space and temperature limitations.


110.3(B)

Many times inspectors are called upon to judge the suitability of equipment in situations

not covered in the NEC. In these situations 110.3(B) gives the necessary guidance required

to make intelligent choices.

Installation and Use. Listed or labeled equipment shall be used or installed in accordance

with any instructions included in the listing or labeling.

NCGS 66.25 requires all electric equipment to be listed.

The instructor should cover the various booklets published by testing laboratories, calling

attention to the general information included i.e. : UL Whitebook.

110.13(B)

Stress cooling where ambient temperatures must be maintained due to the equipment

limitations, characteristics, or listing.

110.14(C)

The temperature limitations of conductors selected are based on the circuit ampacity of 100

Amperes or less, or greater than 100 amperes.

110.22

Stress the importance of identifying disconnecting means as required in 110.22. This

marking allows prompt and accurate disconnection for servicing equipment in time of

emergency.

110.26(C)(2)


Larger access and working spaces are required for equipment rated 1200 amperes or more

and over 6 feet wide.

110.30

Conductors and equipment used on circuits over 600 volts must meet more stringent

requirements than those under 600 volts. 110.31 covers measurements required for

properly protecting the public and those required to service the equipment. The instructor

should point out the different means of protection for qualified and unqualified persons

both indoors and outdoors. Many outdoor overhead installations are not covered by the

NEC but a Fine Print Note refers us to the National Electrical Safety Code.

110.32

The instructor should point out differences in work space, guarding and entrance and

access for 600 volts or less (110.26) and over 600 volts 110.30 through 110.34. Where

equipment is located in a room or enclosure, suitable barriers must be installed to separate

high voltage and low voltage equipment.

110.34(C)

It is very important that rooms or enclosures containing exposed live parts be kept locked.

The access doors must be properly marked with warning signs.

APPLICATION:

If time will allow, have the students answer the questions on the worksheet.

CHECKING AND FOLLOW-UP:




ARTICLE 110

Level II

WORKSHEET

1. Equipment must be installed:

a. According to Code only

b. According to listing and labeling of equipment

c. The way the inspector wants.

d. The way the owner wants.

2. Each disconnecting means required by the NEC shall be:

a. Marked at its point of origin

b. Marked to indicate its purpose

c. Marked in a permanent manner

d. Marked by all of the above

3. The minimum clear working space required between the front of a 277/480V,

switchboard and a concrete wall is which of the following?

a. 3 feet

b. 3.5 feet

c. 4 feet

d. 5 feet

4. Illumination shall be provided for all working spaces about service equipment installed

in which of the following locations?

a. dwelling units

b. commercial buildings

c. in industrial buildings

d. all of the above

5. In a new panel board installation, the minimum headroom clearance shall be which of the

following?

a. 6 feet

b. 6 ½ feet

c. 3 feet

d. 5 feet



ARTICLE 110

Level II

ANSWER KEY

1. b, according to listing and labeling of equipment 110.3(B)

2. d, all of the above 110.22(A)

3. b, 3.5 Table 110.26(A)(1)

4. d, all of the above 110.26(D)

5. b, 6 ½ feet 110.26(E)


BRANCH CIRCUIT AND FEEDER CALCULATIONS

ARTICLE 220

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the requirements for

determining the number of branch circuits required and for computing branch circuit and

feeder loads using different voltages, and ratings.

INTRODUCTION:

This lesson should introduce the student to basic electrical formulas and methods used to

determine sizes of branch circuits and feeders. Explain to class that you will cover

requirements for calculations of branch circuits, feeders and services. Make sure that class

knows the difference in residential and commercial applications.


Review Article 220 level I in the NEC. Briefly review the lesson on residential

requirements for feeders and branch circuits and their calculations. Then, cover the

commercial application for branch circuits and feeder services. Give examples using table

220.12.

Note: V/A per square meter on table.

APPLICATION:

If time will allow, let the class answer the questions on the worksheet.





ARTICLE 220

Level II

WORKSHEET

1. Which of the following is the minimum number of 120 volt, 2 wire, 15 amp, branch circuits

for the general lighting loads for a 2100 square foot single family dwelling?

a. 3

b. 4

c. 5

d. 6

2. A 20 KW, 240 volt, 3-phase, continuous load is to be served with THW copper. Which of

the following is the minimum size conductor permitted for the load?

a. 3

b. 4

c. 5

d. 6

3. A 30 KW, 208 volt, 3-phase, continuous load is to be supplied with 75° C copper

conductors. Which of the following is the minimum size conductor permitted for the load?

a. 4

b. 2

c. 1

d. 3

4. Sign and outline lighting outlets shall be calculated at what minimum volt-amperes for each

required branch circuit specified in 600.5(A).

a. 1200

b. 1400

c. 1600

d. 1800


5. A 120/240 volt, 3 wire feeder is to serve eight household electric clothes dryers rated at 5

KW. Using Article 220.54, what is the minimum volt amperes required for this feeder?

a. 16,800 volt amperes

b. 24,000 volt amperes

c. 28,000 volt amperes

d. 40,000 volt amperes

6. Fixed electric space heating loads shall be calculated at what percent of the total connected

load.

a. 60 percent

b. 80 percent

c. 100 percent

d. 125 percent

7. An installation has a total linear load of 500 amperes. Which of the following is the

minimum size ampacity of the neutral conductor?

a. 350 amp

b. 500 amp

c. 410 amp

d. 300 amp

8. Compute the Load for a 5000 sq. ft. store building with 90 duplex general purpose

receptacles, 50 feet of show window and a 20 ampere sign circuit. Service is 120/208 volt

3 phase.

a. 127 amperes

b. 220 amperes

c. 191 amperes

d. 300 amperes

9. If THW copper conductors are used, what is the minimum size service-entrance conductors

required?

a. 350 kcmil

b. 3/0

c. 4/0

d. # 1


10. A new all electric restaurant has a total connected load of 260 KVA. Compute the load

using the optional calculation. Determine the minimum size of the service entrance

conductors if THW copper conductors are used. Voltage is 480/277 volt 3 phase.

a. 500 kcmil

b. 4/0

c. 3/0 kcmil

d. 250 kcmil



ARTICLE 220

Level II

ANSWER KEY

1. b, (2,100 x 3) / 120 / 15 = 3.5 = 4 circuits

220.12

2. d, (20,000 x 1.25) / 1.732 / 240 = 60.14 (Table 310.15(B)(16) use #6 THW Cu.)

220.19(A)(1), 310.15(A)(1), Table 310.15(B)(16)

3. b, (30,000 x 1.25) / 1.732 / 208 = 104.09 amps (Table 310.16 use #2 THW Cu)

220.19(A)(1), 310.15(A)(1), Table 310.15(B)(16)

4. a, 220.14 (F)

5. b, (8 x 5000 x .6) = 24,000 (Table 220.54)

6. c, 100, 220.51

7. b, 500 amp (220.61)

8. a, 127 amperes (230.42(A))

Gen. Lighting 5,000 X 3 = 15,000 (220.12)

Show Window 50 X 200 = 10,000 (220.43)

Sign 1,200 (220.14(F))

26,200

x 1.25 (230.42(A)(1))

32,750 continuous load

Receptacles 90 X 180 = 16,200 (220.44)

- 10,000 (at 100%)

6,200

x .50 Demand

3,100

+10,000

13,100 VA Non-continuous.

Total 32,750 + 13,100 = 45,850

45,850/(208 x 1.732) = 127 amp

9. d, #1 (230.42(A)(1), Table 310.15(B)(16))

10. c, 3/0 (220.88)


STORE BUILDING Example

A 1400 sq. ft. store building has 25 ft. of show window. There are 30 duplex receptacles. Ten,

120 volt light fixtures rated at 260 volt-amperes each are installed. A 20 ampere outside sign

circuit is provided. Computed the minimum allowable ampacity of the service conductors if a

120/240 volt single phase service is used.

NONCONTINUOUS LOADS

Receptacle Load

30 receptacles at 180 VA = 5,400 VA total............5,400 VA

(Insufficient load for 220-44 Demand factor)

CONTINUOUS LOADS

1400 sq. ft. X 3 VA................................................................................4200 VA

(10 lights X 260 VA = 2600 VA)

Show Window 25 ft. X 200 VA...............................................……….5000 VA

TOTAL CONTINUOUS LOAD.............................9,200 VA

X 1.25

11,500 VA

Outside Sign per Section 600-5(b)(3) 1200 VA

plus noncontinuous load......................... +5400 VA

TOTAL CONTINUOUS & NONCONTINUOUS...........…….18,100 VA

18,100/240 Volts = 75.42 (round to 75 amperes)


OUTSIDE BRANCH CIRCUITS AND FEEDERS

ARTICLE 225

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with electrical equipment and

wiring located on the outside of buildings, structures or poles on the premises served.

INTRODUCTION:

Outside branch circuits are typically those circuits located on the exterior of buildings

and/or structures. This Article covers many aspects of outside wiring such as load

calculations, conductor coverings and sizes, minimum conductor size, overcurrent

protection and more. One typical place you might find this outside wiring is in business

areas such as parking lots. There are many other Articles in the Code that deal with outside

circuits and they should also be consulted when the need arises. One such example might

be the wiring around a swimming pool.


In order to determine the load on outdoor branch circuits you should consult with Section

220.12. Also, the load on outdoor feeders shall comply with Part II of Article 220.

Where open wiring on insulators is within 10 feet of buildings it shall be covered or

insulated. See Section 225.4 for different types of coverings (Rubber Covered or

Thermoplastic) for various situations.

See Tables 310.15 (B)(16)through 310.60 (C)(86) for information on conductor sizes.

When lighting equipment is installed outdoors, the branch-circuits shall comply with

Article 210 and 225.7(B through D).

The Feeder or branch-circuit disconnecting means shall have a rating of not less than the

calculated load to be supplied, determined in accordance with Parts I and II of Article 220

for branch circuit, Part III or IV of Article 220 for feeders, or Part V of Article 220 for farm

loads.

The restrictions on wiring for outside wiring surfaces of buildings are covered in Section

225.10. When dealing with circuit entrances and exits, see the requirements listed in

230.52

See Table 230.51(C) for open conductor spacings. Open conductors of different circuits

shall be separated by not less than 4 inches. For information on the separation of

conductors on poles see Section 225.14(D).


Supports over buildings see Section 230.29, points of attachment see Section 230.26, , and

means of attachment are covered in Section 230.27. Ground clearances are outlined in

Section 225.18.

Horizontal clearances shall not be less than 3 feet. Final spans of feeders or branch circuits

to a building shall be permitted to be attached to the building if kept 3 feet from windows,

doors, porches, fire escapes or similar locations; however, when conductors run above a

window it shall be permitted to be less than 3 feet. See Section 225.19(E) for clearances in

zones for fire ladders.

Other various Articles should be consulted concerning mechanical protection and

multiconductor cables and raceways on exterior surfaces of buildings. Underground circuits

shall comply with Section 300.5.

Outdoor lampholders when attached as pendants, the connection shall be staggered. Also,

if terminals that puncture the insulation of conductors are used to make contact, they should

only be used on stranded type conductors. See Section 225.25 for location of outdoor

lamps.

Live vegetation, such as trees may not be used to support overhead conductor spans.

APPLICATION:

If time will allow, let the class answer questions on the worksheet.





ARTICLE 225

Level II

WORKSHEET

1. When without messenger wires, overhead conductors for festoon lighting shall not be

smaller than which of the following?

a. (a) # 14

b. (b) #12

c. (c) #10

d. (d) #8

2. Open conductors on insulators shall be insulated or covered, if they are installed within

how many feet of a building or other structure?

a. 10 feet

b. 12 feet

c. 15 feet

d. 18 feet

3. Conductors run above the top level of a window shall be permitted to be at which of the

following?

a. Less than 3 feet from the window.

b. Less than 5 feet from the window.

c. Less than 2 feet from the window.

d. Less than 6 feet from the window.

4. Where buildings exceed three stories or 50 ft. in height, overhead lines shall be arranged,

where practicable, so that a clear space (or zone) at least which of the following distance will

be left adjacent to the building?

a. 6 ft. wide

b. 3 ft. wide

c. 8 feet wide

d. 7 feet wide


5. Open conductors shall be separated from open conductors of other circuits or systems by

not less than which of the following distance?

a. 3 inches

b. 5 inches

c. 6 inches

d. 4 inches



ARTICLE 225

Level II

ANSWER KEY

1. b, #12 225.6(B)

2. a, 10 feet 225.4

3. a, less 225.19(D)(1) exception

4. c. 6 feet 225.19 (E)

5. d, 4 inches 225.14 (C)


OVERCURRENT PROTECTION

ARTICLE 240

LEVEL II

OBJECTIVE:

After completing this lesson, each student should be familiar with the requirements of

Section 240.13 and 240.4(B) & (C).

INTRODUCTION:

This lesson should introduce the inspector to the requirements for overcurrent devices rated

800 amperes and ground protection of equipment.


Provide a complete clarification and explanation of 240.4 (D) small conductors and the

relation of size and ampacity ratings. Indicate the standard Ampere ratings of fuses and

fixed-trip circuit breakers and cover the ratings. Explain the difference in the requirement

for conductors being fed from overcurrent devices rated 800 amperes or less or from

overcurrent devices rated above 800 amperes. Explain the ground fault requirement for

solidly grounded wye electrical systems of more than 150 volts to ground, but not

exceeding 600 volts phase to phase and the main disconnect rated 100 amperes or above.

APPLICATION:


CHECKING THE FOLLOW-UP:

If time will allow, correct the worksheet and discuss results.



ARTICLE 240

LEVEL II

WORKSHEET

1. The next higher standard overcurrent device rating (above the ampacity of the conductors

being protected) shall be permitted to be used, provided:

(a) The conductors being protected are not part of a multioutlet branch circuit

supplying receptacles for cord and- plug-connected portable loads.

(b) The ampacity of the conductors does not correspond with the standard ampere

rating of a fuse or a circuit breaker without overload trip adjustments above its

rating (but that shall be permitted to have other trip or rating adjustments).

(c) The next higher standard rating selected does not exceed 800 amperes.

(d) All of the above

2. Ground-fault protection of equipment is required for solidly grounded wye systems of more

than 150 volts to ground but not exceeding 600 volts phase to phase for each building or

structure main disconnect rated at which of the following?

(a) 800 amperes or more.

(b) 1,000 amperes or more.

(c) 600 volts or more.

(d) 300 volts to ground.

3. Which of the following statements is true about Edison-base type Plug fuses?

I- shall be used only for replacements in existing installations where there is

no evidence of overfusing or tampering.

II- fuse holder will only accept the correct rated fuse

a. I only

b. II only

c. both I & II

d. neither



ARTICLE 240

LEVEL II

ANSWER KEY

1. d, all of the above 240.4(C)

2. b, 1000 amperes 240.13

3. a, I only 240.51


GROUNDING

ARTICLE 250

LEVEL II

OBJECTIVE:


250.30(B), Grounding Separately Derived Alternating-Current Systems., and 250.66, Sizes

of Alternating-Current Grounding Electrode Conductor.

INTRODUCTION:

This lesson should familiarize the student with the necessary uses of the grounded

conductor.


Provide a detailed opening starting with the scope 250.1 and the relation to Figure 250.1.

You will need to provide details of all 9 parts as it is related to Grounding and Bonding to

help eliminate the confusion between the two. Once the group has the understanding of

Grounding and Bonding, then you can go over the article. Review Article 250 of Level I in

the NEC. Briefly review the information in 250.30 and 250.66. Give example of different

grounding electrodes that are permitted in 250.52 and what is not permitted. Give

examples using Table 250.66. Show how the table is used when sizing conductors without

over current protection. Show Table 250.122 and how it is used when you have an

overcurrent protection before the conductor.

APPLICATION:

If time will allow, let the students answer the questions on the worksheet.




GROUNDING

ARTICLE 250

LEVEL II

WORKSHEET

1. Where the service entrance phase conductors are paralleled:

A. The size of the grounded conductor shall be based on total circular mill area

of the parallel conductors.

B. The size shall be based on the equivalent area for parallel conductors.

a. A only

b. B only

c. Both A and B above

d. Neither A nor B above

2. The service entrance conductors for a 120/280 volt, 3 phase, 4 wire system is # 4/0 Cu.

What shall be the grounding electrode conductor size for this installation?

a. #4

b. #2

c. #1/0

d. #2/0

3. A grounding electrode conductor that is the sole connection to the grounding electrode as

permitted in 250.52(A)(5) or (A)(7) shall not be required to be larger than:

a. # 6 Cu. or # 4 Al.

b. # 8 AL or # 10 Cu.

c. # 10 Al or # 12 Cu.

d. # 4 Cu. or # 2 Al


GROUNDING

ARTICLE 250

LEVEL II

ANSWER KEY

1. (a) a only 250.24(C)(2)

2. (b) # 2 250.66 Table

3. (a) # 6 Cu. or # 4 AL 250.66(A)


CONDUCTORS FOR GENERAL WIRING

ARTICLE 310

Level II

OBJECTIVE:

Each student should be familiar with conductors for general wiring in high voltage

applications.

INTRODUCTION:

Wiring methods utilized in applications where the voltage exceeds 600 volts require

specialized conductors with appropriate insulation, especially when operating at voltages

exceeding 2000 volts. At these higher voltages it is essential that proper conductors be used

for the application and extreme care must be exercised to install these conductors as

specified by their listing and NEC provisions. This will help to insure the safest possible

installation.

MATERIALS NEEDED :

Samples of conductors with different voltages, shielded conductors and cables, etc.


Review Level 1 Lesson Plans.

Define High Voltage – Over 600 Volts nominal except for grounding which is over 1 KV –

Article 490, 250. Minimum insulation level for neutral conductors of a solidly grounded

high voltage system is 600 Volts. [250.184]

Ampacities of Conductors Rated 2001 to 35,000 Volts for solid dielectric-insulated

conductors shall be permitted to be determined by tables or under engineering

supervision, as provided in 310.60(B) and (C).

Shielding is required and insulation shields must be grounded when using solid dielectric

insulated conductors or direct burial conductors or cables when voltage in either case

exceeds 2000 volts. The purpose of shielding is to confine the voltage stresses to the

insulation. Insulation shields shall be connected to a grounding electrode conductor,

grounding busbar, or a grounding electrode. [310.10(E) & 310.60(B)(1)]

Conductors must be marked as required by 310.120.

Discuss briefly the application of Tables 310.15(B)(16) through 310.60(C)(86) and the

accompanying notes. Tables 310.15(B)(16) through 310.15(B)(21) apply only up through

2000 volts.


Emphasize the importance of reading the table headings carefully to determine the

applicability.

Use ampacity correction factors for Table 310.15(B)(2)(a) & 310.15(B)(2)(b) to briefly

discuss how ambient temperature affects conductor ampacity.

Table 310.15(B)(2)(a) is for ampacity Tables 310.15(B)(16) & 310.15(B)(17) for ambient

temperature of 30 degrees C.

Table 310.15(B)(2)(b) is for Tables 310.15(B)(18) through 310.(B)(21) for ambient

temperature of 40 degrees C.

NOTE: When applying the notes to Tables 310.60(C)(67) through 310.60(C)(86) it would

be advisable to seek assistance from a qualified engineer.

APPLICATION:

If time will allow, let the class time answer questions on the worksheet.

CHECKING AND FOLLOW UP :




ARTICLE 310

WORKSHEET

1. In general, what is the largest solid conductor that may be installed in raceway?

a. #8

b. #10

c. #12

d. #6

2. In general, which is the smallest conductor that may be paralleled?

a. 2/0

b. 1/0

c. 3/0

d. any size

3. Which of the following is not true about paralleled conductors?

a. They shall be the same length.

b. They shall be the same size in circular mil area.

c. They may be different insulation types.

d. They shall have the same conductor material.

4. All of the following may be used in wet locations except:

a. THW

b. THHN

c. THWN

d. RHW

5. What is the ampacity of three #2 THW copper conductors installed in a raceway when the

ambient temperature is 48 degrees Celsius?

a. 100 amperes

b. 86 amps

c. 95 amperes

d. 110 amps


6. What is the maximum over-current device that may be installed on a #12 THHN copper

conductor when there are 30 current carrying conductors installed in the same raceway?

a. 15 amps

b. 20 amps

c. 10 amps

d. 30 amps

7. A 120/208 volt 3 Phase 4 wire feeder is installed in a raceway to supply a 24,000 VA

fluorescent lighting load. This THW copper wire will pass through an ambient temperature

of 100 degrees Fahrenheit. What is the minimum size wire that could be used for this

feeder?

a. # 3

b. # 4

c. # 6

d. # 2

8. A 120/240 volt 1 Phase branch circuit is installed in a raceway to supply a 10,000 VA

water heater, 100 gallons. This THW copper wire will pass through an ambient

temperature of 100 degrees F. What is the minimum size wire that could be used for this

branch circuit?

a. # 8

b. # 6

c. # 4

d. # 3

9. A dwelling has a 120/240 volt 300 AMP service. What would be the minimum size THW

copper wire that could be used for this service?

a. 300 KC-MIL

b. 350 KC-MIL

c. 500 KC-MIL

d. 250 KC-MIL

10. A store has a 120/208 volt 3 Phase 200 AMP service. What would be the minimum size

THW Copper Wire that could be used for this service?

a. 2/0

b. 4/0

c. 3/0

d. 1/0



ARTICLE 310

ANSWER KEY

1. b 310.106(C)

2. b 310.10(H)(1)

3. c shall be of the same type insulation 310.10(H)(2)

4. b, THHN 310.10(C)

5. b 115a X .75 = 86.25a Tb.310.15(B)(16), Tb.310.15(B)(2)(a), Tb.240.4(B),240.6

6. a 30a X .45 = 13.5a Tb.310.15(B)(16), Tb. 310.15(B)(3)(a) Tb 240.4(B),240.6

7. a 24,000/360 = 67a/.88=75.75a/.80= 94.6a Tb. 310.15(B)(16), Tb. 310.15(B)(2)(a),

Tb. 310.15(B)(3)(a), 310.15(B)(5)

8. b 10,000/240 =41.6a X 125% = 52a/.88=59a Table 310.15(B)(16) ,422-13

9. d 300a X .83 = 249a 310.15(B)(7)

10. c Table 310.15(B)(16)


ARMORED CABLE

ARTICLE 320

Level II

OBJECTIVE:

After completing this lesson each student should be familiar with the requirement for the

installation of Type AC cable.

MATERIALS NEEDED:

Sample of different types of Armored Cable. (If available)

INTRODUCTION:

This Article covers the use and installation requirement for a fabricated assembly of

insulated conductors in a flexible metallic enclosure. Be sure to cover the history of

armored cable, its good and bad qualities as well as the comeback it has made in the

industry.


Cover the permitted uses and uses not permitted for Type AC cable and the change in

320.10 item (1) that allows Type AC cable for use as feeders and branch circuits. Note the

requirements for supporting, bending, terminating and installation in accessible attics and

through studs, joists and rafters. It should be pointed out that 320.23 is referred to in other

cable articles as the method of installation in attic spaces.

APPLICATION:





ARMORED CABLE

ARTICLE 320

Level II

WORKSHEET

1. In general, type AC Cable shall be supported at intervals not exceeding which of the

following?

a. 4 feet

b. 4 ½ feet

c. 5 feet

d. 6 feet

2. Where in accessible attics AC cable is run across the top of floor joists or within what

distance of the floor on the face of a studded rafter the cable shall be protected by

substantial guard strips which are at least as high as the cable.

a. 7 feet

b. 5 feet

c. 3 feet.

d. 2 feet

3. AC cable is not permitted to be used:

a. Wet location

b. Both exposed and concealed work

c. Dry locations

d. In cable trays


ARMORED CABLE

ARTICLE 320

Level II

ANSWER KEY

1. 4 1/2 feet 320.30

2. a, 7 feet 320.23(A)

3. a, motion picture studios 320.12


FLAT CONDUCTOR CABLE INSTALLATIONS

ARTICLE 324

Level II

OBJECTIVE:

After completing this lesson each student should be familiar with the general requirements

of flat conductor cable (FCC) installations.

MATERIALS:

Samples of the cable and components used to make up complete wiring systems plus

installations instruction will enable students to better understand the requirements and their

importance.

INTRODUCTION:

There are several definitions included in this article which must be reviewed before the

regulations are covered. Applications for this type of system are limited and knowledge of

such limitations is most important.


Cover scope, definitions, and limitation of uses found in Part I.

The installation requirements found in Part II should be covered. The showing of

components at the time that the specific requirements are covered will prove beneficial.

The requirements included in Part III are primarily directed to the construction of the

various components of this system. Numerous pieces of equipment will be required,

however, the time spent on these requirements can be minimal.

APPLICATION:






ARTICLE 324

Level II

WORKSHEET

1. FCC systems shall be permitted in all of the following occupancies and locations, except:

a. Damp Locations

b. Office Buildings

c. Store Buildings

d. School Buildings

2. The maximum Voltage to the grounded conductor of FCC systems is:

a. 300

b. 125

c. 277

d. 150

3. What is the maximum size carpet square that can be installed over type FCC cable?

a. 24 inch

b. 39.37 inch

c. 18 inch

d. 48 inch



ARTICLE 324

Level II

ANSWER KEY

1. d, School Buildings 324.12

2. d, 150 324.10(B)(1)

3. b, 1 meter (39.37 inch) 324.41


MINERAL-INSULATED METAL-SHEATHED CABLE

ARTICLE 332

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the requirements for the

installation of MI cable.

MATERIALS NEEDED:

A sample of MI cable. (If available)

INTRODUCTION:

This article covers the requirements for use, installation and construction of Mineral-

Insulated Metal-Sheathed Cable.


Cover the definition of MI cable and show an example of MI cable. Note the other articles

that apply to this wiring method. Emphasize where MI cable is permitted and not

permitted to be used.

Part II covers the installation requirement. Cover these requirements: 332.10, 332.12,

332.17, 332.24, 332.30, and 332.40.

Part III gives the construction requirement. Where the outer sheath is made of copper, it

shall provide an adequate path to serve as an equipment grounding conductor. Where the

outer sheath is made of steel, a separate equipment grounding conductor shall be provided.

In as much as listed equipment will be required, the time spent on these requirements can

be minimal.

APPLICATION:






ARTICLE 332

Level II

WORKSHEET

1. Except where fished in, type MI cable shall be supported at intervals not exceeding?

a. 4 1/2 feet

b.6 feet

c. 10 feet

d.5 feet

2. Bends in Type MI shall not be less than which of the following for cable not more than ¾

inches in external diameter.

a. 2

b.5

c. 6

d.10

3. Which of the following shall be used where type MI cable terminates?

a. End Seal Fitting

b. Listed bonding bushings

c. Termination seals

d. Lock nuts



ARTICLE 332

Level II

ANSWER KEY

1. b, 6 feet 332.30

2. b, 5 332.24

3. a, 332.40


FLEXIBLE METALLIC TUBING

ARTICLE 360

Level II

OBJECTIVE:

After completing this lesson each, student should be familiar with the permitted uses,

construction and installation of flexible metallic tubing.

MATERIALS NEEDED:

Sample of flexible metallic tubing. (If available)

INTRODUCTION:

This article applies to a raceway for electrical conductors which are circular in cross

section, flexible, metallic and liquidtight without a nonmetallic jacket.


Discuss the permitted uses and uses not permitted for flexible metallic tubing.

The minimum size of flexible metallic tubing shall be metric designator 16 (1/2 inch

electrical trade size). Review the two exceptions to this rule. The maximum size of

flexible metallic tubing shall be metric designator 21 (3/4 inch electrical trade size).

Explain how to determine the number of conductors permitted in 1/2 and 3/4 inch trade size

flexible metallic tubing using Table 1 from Chapter 9.

Also explain procedures for determining the number of conductors in a 3/8 inch flexible

metallic tubing using Table 348.22. Explain Table 348.22.

Discuss how to determine minimum radii by explaining tables 360.24(A) & (B).

APPLICATION:






ARTICLE 360

Level II

WORKSHEET

1. Flexible metallic tubing shall be permitted to be used in branch circuits in which of the

following except?

a. In damp locations.

b. Where concealed.

c. In accessible locations.

d. For system voltages of 1,000 volts maximum.

2. A 3/8-inch trade size flexible metallic tubing may be permitted to be installed under which

of the following circumstances?

a. FMT of trade size 3⁄8 shall be permitted in lengths not in excess of 6 ft. as

part of an approved assembly or for luminaires (lighting fixtures).

b. FMT of trade size 3/8 shall be permitted in lengths not in excess of 8 ft. as


c. FMT of trade size 3/8 shall be permitted in lengths not in excess of 4 ft. as


d. FMT of trade size 3/8 shall be permitted in lengths not in excess of 5 ft. as


3. The number of conductors permitted in a 3/4-inch trade size of flexible metallic tubing,

would require you to check which of the following?

a. The percentage of fill specified in Table 1, Chapter 9.

b. The percentage of fill specified in Table 9, Chapter 1

c. The percentage of fill specified in Table 4, Chapter 9

d. The percentage of fill specified in Table 9, Chapter 4

4. The minimum radii for a fixed bend of 1/2-inch flexible metallic tubing should be:

a. 3 1/2 inches

b. 4 inches

c. 5 inches

d. 12 1/2 inches

5. The minimum radii for infrequent flexing use of 3/4 inch flexible metallic tubing should

be:

a. 17 inches

b. 16 7/8 inches

c. 12 1/2 inches

d. 17 1/2 inches



ARTICLE 360

Level II

ANSWER KEY

1. a. damp locations 360.10

2. a, 6 feet 360.20(A) exceptions 1 & 2

3. a, Table 1, Chapter 9 360.22

4. b, 4 inches Table 360.24(B)

5. d, 17 1/2 inches Table 360.24(A)


ELECTRICAL NONMETALLIC TUBING

ARTICLE 362

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the requirements for the

installation of ENT.

MATERIALS NEEDED:

A sample of ENT and fittings. (If available)

INTRODUCTION:

This article covers the requirements for use, installation and construction of a pliable

corrugated raceway of circular cross-section for the installation of circuit conductors.


Cover the definition of ENT and show an example of ENT. Note the other Articles that are

applicable. Special emphasis should be placed on the uses permitted and not permitted.

Note the change in 362.12 that prevents installation any hazardous (classified) location,

except as permitted by other articles in this Code.

Part II covers the installation requirement. Cover minimum and maximum sizes, bending,

supports, etc. (362.10 – 362.60) Note the change for 2008 in Section 362.30 Exception No.

3 that stipulates; For concealed work in finished buildings or prefinished wall panels where

such securing is impracticable, unbroken lengths (without coupling) of ENT shall be

permitted to be fished.

APPLICATION:






ARTICLE 362

Level II

WORKSHEET

1. The maximum trade size of electrical nonmetallic tubing is which of the following?

a. 1 inches

b. 2 inches

c. 4 inches

d. 6 inches

2. Without exception electrical nonmetallic tubing shall be supported in which of the

following methods?

a. Every 3 feet and within 3 feet of each outlet box.

b. Every 4 feet and within 4 feet of each outlet box.

c. Every 6 feet and within 12 inches of each outlet box.

d. Every 5 feet and within 3 feet of each outlet box.



ARTICLE 362

Level II

ANSWER KEY

1. b, 2 inches 362.20(B)

2. 3, 3 362.30(B)


BUSWAYS

ARTICLE 368

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the definition and the

structure of a Busway. General requirements in Part I only are covered.

MATERIALS NEEDED:

Drawings, samples of equipment and materials.

INTRODUCTION:

Explain to students that you are going to briefly cover Part I of this article. Busways are

used on almost all industrial and institutional projects.


Cover general requirements in Part I and definitions and use in Section. [368.2] Discuss

requirements for support [368.30], branches from busways [368.56], reduction in size of

busway [368.17 B] and overcurrent protection. [368.17 A]

APPLICATION:





BUSWAYS

ARTICLE 368

Level II

WORKSHEET

1. Which of the following is/are correct concerning busways?

I. Shall not be installed in hoistways.

II. Busways normally shall be supportive at intervals not exceeding five (5) feet.

a. I only

b. II only

c. Both I and II

d. Neither I nor II

2. Which of the following is/are correct concerning busways?

I. A Dead End of a Busway shall be closed.

II. Busways shall always be installed where they are visible and in the open.

a. I only

b. II only

c. Both I and II

d. Neither I nor II

3. Busways shall be marked with all the following except:

a. Voltage

b. Current

c. Manufacturers name or trademark

d. Frequency


BUSWAYS

ARTICLE 368

Level II

ANSWER KEY

1. c, Both I and II 368.12(B), 368.30

2. a, I only 368.10(C) , 368.58

3. d, frequency 368.120


CABLEBUS

ARTICLE 370

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the structure and

permitted uses of a Cable Bus and distinguish them from wireways, cable tray.

INTRODUCTION:

Instruct students that you will cover the article briefly, because it is not seen often in field.

It is important to be able to recognize Cable Bus.


Use pictures and be certain to cover sections 370.2, 370.3, 370.4, and 370.6

APPLICATION:





CABLEBUS

ARTICLE 370

Level II

WORKSHEET

1. The current carrying conductor in cablebus shall have insulation with a minimum rating of

which of the following?

a. 60 degrees C or higher.

b. 75 degrees C or higher.

c. 85 degrees C or higher.

d. 90 degrees C or higher.

2. The minimum size of conductor permitted in cablebus is which of the following?

a. #2

b. #1

c. #1/0

d. #2/0

3. Cablebus shall be normally supported at intervals not exceeding which of the following?

a. 6 feet

b. 8 feet

c. 10 feet

d. 12 feet


CABLEBUS

ARTICLE 370

Level II

ANSWER KEY

1. b, 75 degrees C 370.20(A)1

2. c, #1/0 370.20(C)2

3. d, 12 feet 370.30(A)


CELLULAR CONCRETE FLOOR RACEWAYS

ARTICLE 372

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with: (1) the type of raceway

covered in Article 372, and not confuse them with Articles 390 or 374. (2) code

requirements for this type of installation.

MATERIALS NEEDED:

NEC, drawings, pictures, handouts.

INTRODUCTION:

Brief overview of Article 372 in code book.


Discuss code sections in 372, use drawings and pictures of raceways. Cover definition and

use in 372.2 and 372.4. Emphasize FPN for 372.4. Review installation requirements in

372.5 through 372.13.

APPLICATION:






ARTICLE 372

Level II

WORKSHEET

1. Which of the following is/are correct concerning the installation of cellular concrete floor

raceways?

I. Conductors shall not be installed where subject to corrosive vapors.

II. Connections from headers to cabinets shall be made by means of metal

raceways.

a. I only

b. II only

c. Both I and II

d. Neither I nor II

2. Except by special permission, the largest conductor permitted to be installed in cellular

concrete floor raceways is which of the following?

a. #2

b. #1

c. #1/0

d. #2/0



ARTICLE 372

Level II

ANSWER KEY

1. c, Both I and II 372.4(1), 372.6

2. c, #1/0 372.10


CELLULAR METAL FLOOR RACEWAYS

ARTICLE 374

Level II

OBJECTIVE:

After completing this lesson each student should:

(1) be familiar with raceways covered in Article 374

(2) be able to distinguish raceways in this article from other articles such as 390 and 372

(3) be familiar with code requirements for this type of installation.

MATERIALS NEEDED:

NEC, drawings, pictures.

INTRODUCTION:

A general, but brief overview of Article 374.


Cover definitions and use; Section 374.2 and 374.3, emphasize Informational note of 374.3.

Review installation requirements in Part I. Use handouts, drawings and pictures of

raceways.

APPLICATION:






ARTICLE 374

Level II

WORKSHEET

1. Which of the following is/are correct concerning the installation of cellular metal floor

raceways?

I. They shall not be installed where subject to corrosive vapors.

II. They shall not be installed in any hazardous location except as permitted by

other articles in the code.

a. I only

b. II only

c. Both I and II

d. Neither I nor II

2. Except by special permission, the largest conductor permitted in cellular metal floor

raceways is?

a. # 2

b. # 1

c. # 1/0

d. # 2/0

3. In cellular metal floor raceways the combined cross-sectional area of all conductors or

cables shall not exceed what per-cent of the interior cross-sectional area of the cell or

header?

a. 25%

b. 40%

c. 50%

d. 75%



ARTICLE 374

Level II

ANSWER KEY

1. c. both I and II 374.3

2. c, # 1/0 374.4

3. b, 40% 374.5


METAL WIREWAYS

ARTICLE 376

AND

NON METALLIC WIREWAYS

ARTICLE 378

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the definition of

wireways, when and where they are used, and be aware of how close they are related to

other raceways such as Busways.

MATERIALS NEEDED:

Pictures, handouts, one type of wireway if available.

INTRODUCTION:

Explain to class that this is a short code section, will be covered briefly, and is important

because it is so commonly used.


Cover code sections, use handouts, drawings, and an actual wireway if available. Review

the definitions and use in 376.2 & 10, the size and number of conductors permitted in

wireways. Note the cross-sectional areas and adjustments factors in 376.22 (A) and (B).

APPLICATION:





METAL WIREWAYS

ARTICLE 376

AND


ARTICLE 378

Level II

WORKSHEET

1. Metal wireways shall be supported where run horizontally at each end and at intervals not

to exceed which of the following?

a. 5 feet

b. 10 feet

c. 15 feet

d. 20 feet

2. The conductors in a wireway have a cross sectional area of 7.2 square inches. Which of the

following is the minimum size wireway permitted?

a. 4" x 4"

b. 6" x 6"

c. 8" x 8"

d. 12" x 12"

3. Nonmetallic wireways shall be supported where run horizontally at which of the following

intervals unless approved for a greater distance?

a. 5 feet

b. 3 feet

c. 10 feet

d. 4 ½ feet

4. Which of the following statements about nonmetallic wireways is true?

a. An equipment-grounding conductor shall be installed with any extension.

b. Nonmetallic wireway shall be marked with the suffix LS.

c. Both a and b

d. Neither a nor b


METAL WIREWAYS

ARTICLE 376

AND


ARTICLE 378

Level II

ANSWER KEY

1. a, 5 feet 376.30(A)

2. b, 6" x 6" 7.2 sq. in. / 20% = 36 sq. in. = 6" x 6" wireway 376.22 &

378.22

3. b, 3 feet 378.30(A)

4. a, an equipment grounding conductor shall be installed 378.70


NONMETALLIC EXTENSIONS

ARTICLE 382

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the provisions of

nonmetallic extensions.

MATERIALS NEEDED:

Samples of nonmetallic extensions. (If available)

INTRODUCTION:

Concealable Nonmetallic Extension. A listed assembly of two, three, or four insulated

circuit conductors within a nonmetallic jacket, an extruded thermoplastic covering, or a

sealed nonmetallic covering. Review the areas that this classification includes.


Explain how nonmetallic extensions may be permitted for use from an existing outlet,

exposed and in a dry location, and for nonmetallic surface extensions.

Also, review uses not permitted for nonmetallic extensions such as: aerial cable, unfinished

areas and voltage between conductor’s limitations, corrosive vapors and through floors and

partitions.

Extensions shall consist of a continuous unbroken length of the assembly without splices;

however, taps may be made under certain conditions.

The installation of nonmetallic extensions shall be installed as specified in Part II.

The marking of nonmetallic extensions shall comply with Section 110.21.

Note the listing requirements in 382.6 (1-5)

APPLICATION:






ARTICLE 382

Level II

WORKSHEET

1. Nonmetallic extensions shall be permitted from an existing outlet on which of the

following circuits?

a. A 15 or 20 ampere branch circuit.

b. A 20 or 30 ampere branch circuit.

c. A 30 or 40 ampere branch circuit.

d. A 40 or 50 ampere branch circuit.

2. Nonmetallic extensions of aerial cable may be used where the voltage between conductors

does

not exceed which of the following?

a. 240 Volts

b. 300 Volts

c. 600 Volts

d. 150 Volts

3. Receptacle-type tap conductors shall be of which of the following type?

a. Receptacle-type

b. Removable-type

c. Grounded-type

d. Locking-type

4. With one exception, nonmetallic surface extensions shall be secured in place by approved

means at intervals not exceeding which of the following?

a. 5 inches

b. 6 inches

c. 8 inches

d. 12 inches



ARTICLE 382

Level II

ANSWER KEY

1. a, 15, 20 382.10(A)

2. b, 300 volts 382.12 #2

3. d, Locking 382.56

4. c, 8 inches 382.30


UNDERFLOOR RACEWAYS

ARTICLE 390

Level II

OBJECTIVE:

After completing this lesson, each student should: (1) understand underfloor raceways as

covered in Article 390, and not confuse them with other similar raceways. (2) know the

basic requirements for this type of installation.

MATERIALS NEEDED:

Code book, drawings, pictures of raceways.

INTRODUCTION:

A brief discussion of Article 390 in the code book.


Cover the use of underfloor raceways and minimum cover requirements in 390.2(A). Also

cover size of conductors, maximum number of conductors in raceways, splices and taps

and what to do when outlets are discontinued. (390.4 – 390.7)

Review installation requirements as covered in 390.4 through 7.

APPLICATION:





UNDERFLOOR RACEWAYS

ARTICLE 390

Level II

WORKSHEET

1. In office occupancies, approved metal flat-top raceways not over 4 inches in width shall be

permitted to be laid flush with the concrete floor surface provided they are covered with

substantial floor linoleum with a thickness not less than:

a. 1/16 inch

b. 1/8 inch

c. 1/4 inch

d. 3/8 inch

2. Which of the following is/are correct concerning underfloor raceways?

I. Dead ends of raceways shall be closed.

II. When an outlet is discontinued or removed, the sections of circuit

conductors supplying the outlet(s) shall be removed from the raceway.

a. I only

b. II only

c. Both I and II

d. Neither I nor II


UNDERFLOOR RACEWAYS

ARTICLE 390

Level II

ANSWER KEY

1. a, 1/16 inch 390.4(D)

2. c, Both I and II 390.8 & 390.10


MESSENGER SUPPORTED WIRING

ARTICLE 396

Level II

OBJECTIVE:

After completing this lesson each student should be familiar with the requirements for

installing messenger supported wiring.

MATERIALS NEEDED:

Example of messenger supported wiring. (If available)

INTRODUCTION:

This Article covers the requirements of a messenger supported wiring system using a

messenger wire to support insulated conductors.


Cover the methods of supporting insulated conductor to the messenger wire. Note the other

Articles that apply to this wiring method. Emphasize the permitted uses -- cable type and

location. Note the uses not permitted. Note the requirements for ampacity, support,

grounding and splices and taps.

APPLICATION:






ARTICLE 396

Level II

WORKSHEET

1. In which of the following locations is messenger supported wiring prohibited?

I. In hoistways.

II. Where subject to physical damage.

a. I only

b. II only

c. Both I and II

d. Neither I or II

2. The conductors of messenger supported wiring shall not be permitted to come into

contact with which of the following?

a. The messenger supports.

b. Structural members.

c. Walls, or pipes.

d. All of the above



ARTICLE 396

Level II

ANSWER KEY

1. c, Both I and II hoistways and where subject to physical damage 396.12

2. d, All of the above 396.30


OPEN WIRING ON INSULATORS

ARTICLE 398

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with open wiring on

insulators, when and where it may be used, and restrictions that may apply.

MATERIALS NEEDED:

Samples, handouts, materials used in field.

INTRODUCTION:

Explain to students that you will cover this article briefly, touching on the most important

sections that apply to Level II inspectors.


This type of installation is not often seen in the field (usually found only in agricultural or

industrial establishments). Cover sections using handouts, samples of materials used in

actual installations. Explain types of wiring and materials used. Use drawings on

chalkboard.

APPLICATION:






ARTICLE 398

Level II

WORKSHEET

1. Which of the following is correct concerning the installations of open wiring on insulators?

I. Shall be permitted on 600 volts, nominal or less for industrial or agricultural

establishment

II. Restricted to dry locations only.

a. I only

b. II only

c. Both I and II

d. Neither I nor II

2. Conductor must be supported within how many inches of a tap or splice?

a. 6 inches

b. 10 inches

c. 12 inches

d. 54 inches

3. When nails are used to mount knobs for open wiring, the nails must be a minimum size of?

a. 8 penny

b. 10 penny

c. 12 penny

d. 16 penny

4. Open wiring in accessible attics with stairways must be protected from physical damage if

it is not installed at least a minimum height of?

a. 2 feet

b. 4 feet

c. 6 feet

d. 7 feet

5. Open conductors shall be separated from metal raceways, piping, or other conducting

material a minimum distance of?

a. 2 inches

b. 4 inches

c. 6 inches

d. 12 inches



ARTICLE 398

Level II

ANSWER KEY

1. a, I only 398.10

2. a, 6 inches 398.30(A)

3. b, 10 penny 398.30(D)

4. d, 7 feet 398.23(A)

5. a, 2 inches 398.19


FIXED ELECTRIC SPACE HEATING EQUIPMENT

ARTICLE 424

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the basic code

requirements for fixed electric space heating.

INTRODUCTION:

This article includes requirements for several different types of heating systems some of

which will only be encountered infrequently such as heating cable, unit heaters, boilers,

central systems, etc. It does not apply to process heating or room air conditioners.


NOTE: This lesson is a review of Level 1, Article 424.

Branch Circuit Requirements

Branch circuits supplying more than one outlet for fixed electric heaters (baseboard

heaters) shall be rated 15, 20, 25 or 30 amperes. Fixed infrared equipment located in other

than residential occupancies can be supplied from branch circuits rated not over 50

amperes. [424.3(A)] Branch circuits supplying only one piece of equipment must be rated

125% of the total load including motors and resistance heaters, except for relays and

contactors which are approved for continuous operation at 100% ampacity [424.3(B)].

Heat pump compressors are covered under Article 440.34 and 35.

Installation

If heating equipment requires more than 60 degrees Celsius insulation on supply wiring, it

must be clearly marked and the marking must be visible after installation. (424.11)

Locations

Units subject to physical damage shall be protected in an approved manner. Climate in wet

or damp areas shall be approved for such location and installed so liquid cannot enter.

(424.12)

Spacing from Combustible Material

Equipment shall be installed to provide manufacture’s requirements for clearance to

combustible materials. 424.13

Control and Protection

A disconnecting means must be provided to disconnect all ungrounded conductors where

supplied from more than one source, disconnects shall be grouped. (424.19)


A disconnecting means for units equipped with supplementary overcurrent devices shall be

within sight from and on the supply side of supplementary overcurrent protection, and

comply with numbers 1 or 2 below.

1. For motors not over 1/8 horsepower, a disconnecting means shall be permitted to serve

both the motor controller and heater if located within sight of both or the disconnecting

means must be capable of being locked in the open position. Where unit switches meet

the requirements of 424.19(C) they may be used as the required disconnecting means.

2. Units containing motors rated over 1/8 horsepower, disconnect described in number 1

above may be used, if within sight of the motor controller and heater.

Please emphasize this: Disconnecting means not within sight from the heater requires either

a separate disconnect be installed or a disconnect capable of being locked open or unit

switches complying with 424.19(C)

A branch circuit switch or circuit breaker may serve as a disconnecting means for units

containing motors not more than 1/8 horsepower where readily accessible for servicing.

Units more than 1/8 horsepower will require a disconnect within sight of motor controller.

Unit switches may be used as disconnecting means where provided with a marked "off"

position and when meeting requirements of 424.19(C) for the type of occupancy involved.

Thermostatically controlled switching devices may be used as both a controller and a

disconnecting means under ALL the following conditions.

Example: thermostats for basement heat

1. Marked "off" position

2. Must open all ungrounded conductors when in "off" position (manually)

3. Must not be capable of being automatically energized when in the manual "off"

position.

4. Must be located as per Section 424.19.

Switches must be of the type indicating the "on" and "off" positions. 419.20

Overcurrent Protection

Space heating equipment supplied by branch circuits in Article 210 shall be permitted

where not supplying motor operated equipment as in Article 430.440. [424.22(A)]

Resistance-type heating elements may not be protected at more than 60 amperes. Where

rated more than 48 amperes, it shall be subdivided not to exceed 48 amperes within each

subdivided load. [424.22(B)]

Overcurrent protective devices for subdivided loads shall be factory installed or factory

provided, accessible and suitable for branch circuit protection. (see Article 240.10).


Conductors supplying supplementary overcurrent protective devices shall be considered

branch circuit conductors. [see 424.22(D].

Field installed conductors between supplementary protective devices and heater shall be

sized not less than 125% of load. Overcurrent protective devices shall comply with Article

240.3. [424.22(E)].

Marking of Heating Equipment

Each unit must have manufacturer's nameplate installed and visible after installation.

[424.28(A & B)]

Space Heating Cables

Area heating cables shall not extend beyond the room in which they originate. They shall

not be installed in closets, over walls or over cabinets. [424.38]

Heating cables must be at least 8 inches from the edge of outlet boxes and junction boxes,

and at least 2 inches from recessed fixtures. [424.39]

Adjacent runs of cable not less than 1 1/2 inch on center and secured at intervals not

exceeding 16 inches. [424.41(B)(F)]

Splices in the cable should be made only where necessary and in no case to alter length of

cable. Cables shall cross joists only at ends of room. [424.41(D)(J)]

Heating cables shall not exceed 16 1/2 watts per linear foot in concrete or masonry floors.

[424.44(A)]

All cable installations must be inspected before being covered. Review typical installation

procedures. [424.45]

Duct Heaters

All duct heaters must first be identified as suitable for installation. [424.58]

If duct heater is located within 4 feet of a heat pump or air conditioner it must be identified

as suitable for such installation. [424.61]

The fan circuit must be interlocked to insure fan is running when heater is on. [424.63]

Each heater must be provided with limit devices. [424.64]

A disconnecting means must be at or within sight from the controller. [424.65]

Installation must meet manufacturer's instructions. [424.66]


Electrode-type Boilers

Branch circuit conductors and protective devices shall be calculated at 125% of total load

except for contactors, relay, or other devices approved for continuous operation at 100% of

rating. [424.82]

Over temperature and over pressure limiting controls are required and must meet the same

requirements as for resistance-type boilers. [424.83]

All boilers must be marked with manufacturer's name, rating and electrical supply required.

In addition, a warning: "ALL POWER SUPPLIES SHALL BE DISCONNECTED

BEFORE SERVICING INCLUDING SERVICING THE PRESSURE VESSEL." must

appear. [424.86]

Electric Radiant Heating Panels and Heating Panel Sets

This section of Article 424 applies to wall heaters, baseboard heaters and other heating

units, which may be exposed or concealed when installation is complete. Heating panels

and heating panel sets must be installed to meet manufacturer's installation instructions,

and the conditions of Section 424.93(A)(1) & (2):

1. Must not be installed subject to physical damage

2. Must not run through or above walls, partitions, or other structures that extend to

ceilings.

3. Must not run through or in thermal insulation.

Excess non-heating leads of heating panels and heating panel sets may be cut to desired

length. [424.97]

Heating panels or panel sets installed in concrete or poured masonry must meet the

requirements of Section 424.98. (Review requirement).

Heating panels installed under floor covering must be installed in accordance with

instructions and identified for such use and provided with fault protection in accordance

with Section 424.99. It is important for the inspector to have access to installation

instructions for the specific panel installed. Inspection must be made prior to applying

floor covering. Heating panels installed under floor covering shall not exceed 15 watts per

square foot. [424.99]

APPLICATION:






ARTICLE 424

Level II

WORKSHEET

1. Branch circuits supplying two or more outlets for fixed electric heat in a dwelling shall not

be rated more than which of the following?

a. 15 amperes.

b. 20 amperes.

c. 25 amperes.

d. 30 amperes.

2. Ampacity of branch circuit conductors supplying fixed electric space heating equipment

with resistance elements shall not be less than what percentage of the total load of the

heaters and motors.

a. 150 percent

b. 125 percent

c. 100 percent

d. 80 percent

3. The disconnecting means for electric heat units shall be in sight and a maximum distance

from the unit of?

a. 10 feet

b. 12 feet

c. 25 feet

d. 50 feet

4. For fixed electric space-heating equipment without a motor rated over 1⁄8 hp, the branch-

circuit switch or circuit breaker shall be permitted to serve as the disconnecting means

where the switch or circuit breaker in which of the following conditions?

I. Is within sight from the heater

II. Is capable of being locked in the open position.

a. I only

b. II only

c. Neither I or II

d. Both I and II


5. Which of the four things listed are necessary for a thermostatically controlled switching

device to be used as both the controller and disconnecting means?

a. Marked "off" position.

b. Directly open all ungrounded conductors when manually placed in "on" position.

c. Can be energized automatically when in "off " position.

d. Located as specified in 430.19.

6. Heating equipment requiring supply conductors to be rated over which of the following

temperatures shall be clearly marked?

a. 60 degrees C

b. 75 degrees C

c. 90 degrees C

d. 40 degrees C

7. Resistance-type heating elements in electric space heating equipment shall be protected at

not more than which of the following in amperes?

a. 40 amperes

b. 50 amperes

c. 60 amperes

d. 125 amperes

8. The conductors supplying the supplementary overcurrent protective devices shall be

considered which of the following?

a. Feeders

b. Branch circuit conductors

c. Service conductors

d. Lateral circuit conductors

9. What would be the minimum THW wire size and fuse size for a 5 KW resistance heater

with a 3 ampere fan motor rated 240 volt, 1 Ø?

a. # 8 and 40 amperes

b. # 10 and 30 amperes

c. # 6 and 50 amperes

d. # 12 and 25 amperes


10. Electric space heating cables in ceilings shall be located a minimum distance of how far

from recessed light fixtures?

a. 2 inches

b. 8 inches

c. 12 inches

d. 16 inches

11. Heating cables shall be furnished complete with factory-assembled non-heating leads at

which of the following lengths?

a. At least 4 ft. in length.

b. At least 5 feet in length

c. At least 6 feet in length.

d. At least 7 feet in length.

12. When installing heating cables in ceilings, which of the following is the minimum amount

of

non-heating leads permitted to be left in a junction box?

a. 2 inches

b. 4 inches

c. 6 inches

d. 8 inches

13. Heat pumps and air conditioners having duct heaters closer than which of the following

distance to the heat pump or air conditioner shall have both the duct heater and heat pump or

air conditioner identified as suitable for such installation and so marked?

a. 2 feet

b. 4 feet

c. 3 feet

d. 6 feet

14. Duct heater controller equipment shall be either accessible with the disconnecting means

installed at or within sight from the controller in accordance with which of the following

Code sections?

a. 430.250 (A)

b. 430.248 (A)

c. 424.20 (A)

d. 424.19 (A)


15. A boiler employing resistance-type heating elements not contained in an ASME rated and

stamped vessel shall have the heating elements protected at not more than which of the

following?

a. 48 amperes

b. 60 amperes

c. 70 amperes

d. 100 amperes

16. A 25 KW, 480 volt, 3 phase electric heat unit is to be installed using THW copper; which

of the following is the minimum size conductor permitted for the branch circuit conductor

for this unit? Note: All conductors are considered to be copper and operating at 60 degrees

unless otherwise stated.

a. #10

b. #8

c. #6

d. #4

17. An ASME rated boiler shall have its loads subdivided if the load on an element exceeds:

a. 24 amperes

b. 120 amperes

c. 48 amperes

d. 60 amperes

18. List the marking not required on electrode type boilers.

a) Manufacturer’s address.

b) Rating in volts, amperes, and KW.

c) Supply frequency, number of phases, and number of wires.

d) Marked "Electrode - type boiler"

e) Marked " ALL POWER SUPPLIES SHALL BE DISCONNECTED

BEFORE SERVICING INCLUDING SERVICING THE PRESSURE

VESSEL."

19. A complete assembly provided with a junction box or length of flexible conduit for

connection to a branch circuit is which of the following?

a. A radiator panel.

b. A radiant heating panel.

c. A heating panel set.

d. A heating boiler set.


20. Heating panels or panel sets installed under floor covering shall not exceed which of the

following in watts per square foot of heated area?

a. 25 watts

b. 20 watts

c. 16 watts

d. 15 watts



ARTICLE 424

Level II

ANSWER KEY

1. d, 30 amperes 424.3(A)

2. b, 125% 424.3(B)

3. d, 50 feet 424.19(A)

4. d, Both I and II 424.19(B)(1)

5. a, Marked "off" position. 424.20(A)

6. a, 60 degrees C 424.11

7. c, 60 424.22(B)

8. b, Branch circuit conductors 424.22(D)

9. b, Use # 10 THW copper wire and a 30 ampere fuse.

(5 KW 5000/240 = 20.8 + 3 = 23.8 times 125% = 29.7) 424.3(B)

10. a, 2 inches 424.39

11. d, at least 7 feet in length 424.34

12. c, 6 inches 424.43(B)

13. b, feet 424.61

14. d, 424.19 424.65

15. a, 48 amperes 424.72(B)

16. b, #8, 25,000 ÷480 ÷ 1.732 = 30.0 amperes x 125% = 37.58 amperes 310.16

Look in 310.16 at THW copper = # 8 wire

17. b 120 amps 424.72(A)

18. a, Manufacturer’s name is required 424.86

19. b, A radiant heating panel 424.91

20. d, 15 Watts 424.99(B)


FIXED OUTDOOR ELECTRIC DE-ICING AND SNOW-MELTING EQUIPMENT

ARTICLE 426

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the requirements for

Fixed Outdoor Electric De-Icing and Snow-Melting Equipment.

MATERIALS NEEDED:

Pictures of different types of units including their installations.

INTRODUCTION:

The requirements of this article apply to electrically energized heating systems and the

installation of these systems.


Article 426 covers snow-melting and de-icing equipment embedded in driveways, walks,

steps and other areas. Exposed systems are used for drainage systems, bridges, roofs and

other structures. Emphasis should be placed on definitions in 426.2 relating to this article.

Note other applicable articles covered in 426.3. Branch circuit and overcurrent sizing is

covered in 426.4, note the 125% requirement for the branch circuit conductors.

Part II covers the installation requirements. Special attention should be given to 426.10 (2)

emphasizing that these systems shall be installed according to the manufactures drawings

and instructions. Also note 426.14 for special permission requirements.

Part III covers resistance heating elements requirements. Emphasis should be placed on

spacing in 426.20(B) cover 426.20(C) secured in (D) and expansion and contractions in

(E).

Installation requirements for the non-heating leads for embedded equipment should be

covered emphasizing the raceways, grounding and lead in junction boxes.

Part IV covers impedance heating. Explain impedance heating and also skin effect heating.

In Part V go over disconnection and overcurrent protection. In 426.51 controllers, explain

the different types of controllers and their functions.


APPLICATION:





FIXED OUTDOOR ELECTRIC DE-ICING

AND SNOW-MELTING EQUIPMENT

ARTICLE 426

Level II

WORKSHEET

1. The ampacity of branch-circuit conductors for snow-melting equipment shall not be less

than what percent of the total load of the heaters?

a. 80 %

b. 100 %

c. 125 %

d. 250 %

2. Resistance heating units of snow-melting equipment shall not exceed which of the

following in watts per square foot of heated area?

a. 100 watts psf

b. 120 watts psf

c. 350 watts psf

d. 500 watts psf

3. Each factory-assembled fixed outdoor de-icing heating unit shall be:

A) Legibly marked within 3 inches of each end of the non-heating leads

B) Marked with the permanent identification symbol, catalog number, and rating in

volts and amperes.

a. A only

b. B only

c. both A and B

d. neither A nor B

4. The factory installed cord and plug, as well as plug connected equipment rated which of the

following shall be permitted to be the disconnecting means.

a. 20 amperes or less and 150 volts or less to ground

b. 30 amperes or less and 150 volts or less to ground

c. 40 amperes or less and 150 volts or less to ground

d. 50 amperes or less and 150 volts or less to ground


5. Fixed outdoor de-icing equipment shall be protected by one of the following methods:

a. motor rated switch

b. circuit breaker

c. fuses

d. ground fault branch circuit protection


FIXED OUTDOOR ELECTRIC DE-ICING

AND SNOW-MELTING EQUIPMENT

ARTICLE 426

Level II

ANSWER KEY

1. c, 125 426.4

2. b, 120 426.20

3. c, both A and B 426.25

4. a, 20, 150

426.50(B)

5. d, ground fault branch circuit protection 426.28


MOTORS, MOTOR CIRCUITS, AND CONTROLLERS

ARTICLE 430

Level II

OBJECTIVE:

After completing this lesson, each student should have an understanding of the sections in

Article 430 that pertain to level II inspectors.

INTRODUCTION:

Much of Article 430 has been covered in Level I. The intent here is to review the

information and place additional emphasis on the following:


As with any installation; safety depends on proper application of equipment. Equipment

installed in location where dust or flying material are present and will collect on or in

motors in such quantities to seriously interfere with ventilation and cooling, dangerous

temperatures will result. Suitable types of enclosed motors shall be used. (Section 430.16)

As a general rule, motor applications are considered to be for continuous duty unless the

nature of the apparatus it drives is such that the motor cannot operate continuously with

load under any conditions of use. See the Duty-Cycles Service, show Table 430.22(E) for

Exceptions involving Short-Time Duty, Intermittent Duty, Periodic Duty, and Varying

Duty applications. Review the requirements of several motors on one branch circuit found

in Section 430.53(A).

Cover in detail the requirements found in Section 430.53(C) for other Group installations.

Give example and have controllers to show how to determine maximum rating of fuse and

for circuit breakers.

Section 430.72 (A) and (B) was covered in Level I. Sub-Section (C) needs to be added so

that control circuit transformers are provided with the necessary overcurrent protection.

APPLICATION:

If time will allow, let the class time answer the questions on the worksheet.




MOTORS, CIRCUITS, AND CONTROLLERS

ARTICLE 430

Level II

WORKSHEET

1. For a portable motor, the controller shall be permitted to be an attachment plug and

receptacle if the motor is rated at not over which of the following?

a. 1/8 Hp

b. 1/3 Hp

c. 3/4 Hp

d. 1 Hp

2. A motor is to be connected to a feeder tap not over 25 feet in length. Which of the

following is correct?

I. Tap conductor must have an ampacity at least one-third that of the feeder

conductor.

II. Be protected from physical damage.

a. I only

b. II only

c. both I and II

d. neither I nor II

3. A 480 volt, 40 Hp, 3 phase, Code Letter "B" synchronous type motor is to be protected by

dual element fuses. Which of the following is the maximum size fuse permitted to protect

the branch circuit conductor for the motor? (Motor has a power factor of .90). (Do not use

Exception).

a. 50 ampere

b. 60 ampere

c. 100 ampere

d. 80 ampere

4. Which of the following is the minimum ampacity permitted to size the branch circuit

conductor for a 40 Hp, 480 volt, 3 phase, synchronous type motor with a power factor of

.90?

a. 45 amperes

b. 72 amperes

c. 50 amperes

d. 70 amperes


5. Three motors are supplied by the same feeder, one with a full load ampacity of 28 amps

protected by a 45 amp dual element fuse, the other two with a full load ampacity of 22

amperes each, protected by 30 ampere dual element fuse each. Which of the following is

the maximum size fuse permitted to protect the feeder?

a. 70 amperes

b. 80 amperes

c. 90 amperes

d. 100 amperes


conductor for a 10 Hp, 208 volt, single phase, squirrel cage, induction type motor?

a. 39

b. 55

c. 60

d. 69

7. An intermittent duty motor, serving a freight elevator, is a 30 minute rated motor. Which

of the following is the minimum percent to be used when calculating the branch circuit

conductor for this motor?

a. 80%

b. 90%

c. 115%

d. 125%

8. When installing branch circuit conductors and a controller, which of the following is

correct? (Motor is a continuous duty motor)

I. Thermal overload heater must be installed in all ungrounded conductors.

II. Branch circuit conductor must be calculated at 125% of the full load current of

the motor.

a. I only

b. II only

c. both I and II

d. neither I nor II

9. The branch circuit conductors for a motor are protected by time-delay (dual element) fuses.

If the fuses are not holding on the line, they may be increased to a maximum of:

a. 150%

b. 175%

c. 200%

d. 225%


10. A feeder is to supply two motors, with a full load ampacity of 28 amperes each and a non-

continuous lighting load of 100 amps. Which of the following is the minimum size

conductor permitted for this feeder, using THHN copper?

a. #3

b. #2

c. #1

d. #1/0

"NOTE" ALL MOTORS IN THESE QUESTIONS (11-16) ARE AC TYPE MOTORS.

11. What is the minimum size THW conductor permitted to serve as the branch circuit

conductors for a 10 Hp, 240 volt, 3 phase, squirrel cage, induction type motor?

a. #12

b. #10

c. #8

d. #6


conductors for a 30 Hp, 480 volt, 3 phase, synchronous type motor?

a. 32 amperes

b. 40 amperes

c. 44 amperes

d. 63 amperes

13. A general use, non-fusible type disconnect shall be rated at what percent of the full load

current of the motor?

a. 80%

b. 100%

c. 115%

d. 125%

14. Which of the following is the normal size motor overload permitted for a 20 Hp, 240 volt, 3

phase, squirrel cage, induction type motor with a service factor of 1.15 and a nameplate

current rating of 52 amperes? (The motor overload shall be based on the nameplate current

rating).

a. 62.10

b. 67.50

c. 70.20

d. 75.60


15. A feeder is to serve three motors; one with a full load ampacity of 42 amperes, two with a

full load ampacity of 28 amperes each. Using THW copper, which of the following is the

minimum size feeders permitted for these three motors?

a. #4

b. #3

c. #2

d. #1

16. Which of the following is the maximum size dual element fuses permitted to protect the

branch circuit conductors for a 5 Hp, 240 volt, single phase, squirrel cage, induction type

motor? (Do not use any exceptions)

a. 40 amperes

b. 45 amperes

c. 50 amperes

d. 60 amperes


MOTORS, CIRCUITS, AND CONTROLLERS

ARTICLE 430

Level II

ANSWER KEY

1. b, 1/3 Hp 430.81(B)

2. c, both I and II 430.28(2)

3. c, 70 amp 40 Hp. 52 amperes x 1.1 = 57.2 amperes x 175% = 100 = 100 ampere

fuse

Table 430.250, 430.52,

Table 430.52

4. b, 56 amps; 40 Hp. 52 amperes x 1.1 = 57.2 amperes x 125% = 71.5 = 70 amperes

Table 430.250, 430.22(A),

Table 310.15(B)(16), 240.6

5. b, 80 amperes, 45 + 22 + 22 = 89 amperes = 80 amperes 430.62

6. d, 69; 55 x 125% = 68.75 = 69 430.22(A),

Table 430.148

7. b, 90% 430.22(E),

Table 430.22(E)

8. c, both I and II 430.22(A), 430.32(A)(1),

Table 310.15(B)(16)

9. d, 225% 430.52(C) Exception 2(b)

10. d, #1/0 , (28 x 125%) + 28 + 100 = 163 amperes 430.24

11. b, #10, 430.22(A), Table 430.150,

Table 310.15(B)(16)

28 amperes x 125% = 35 amperes = #10 THW

12. b, 40 amperes, 32 amperes x 25% = 40 amperes 430.22(A),

Table 430.150

13. c, 115% 430.110(A)

14. b, 67. 50 , 54 amperes x 125% = 67.50 430.6(A)(2), 430.32(A)(1)

15. c, #2; (42 x 125%) + 28 + 28 = 108.5 amperes = #2 430.24, Table 310.15(B)(16)

16. b, 45 amperes ; 28 amperes x 175% = 49 amperes = 45 amperes

430.6, 430.52,

Table 430.52


TRANSFORMERS AND TRANSFORMER VAULTS

ARTICLE 450

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the code requirements

for installations of transformers, covering the location normally used, different types and

purposes.

MATERIALS NEEDED:

Pictures or transparencies of different types of transformers.

INTRODUCTION:

With few exceptions, this article applies to all transformers. (See 450-1 for exceptions)

Transformers are most likely encountered in large commercial and industrial installations.


Article 450 covers individual transformers, single or polyphase, identified by a single

nameplate. This article also covers the installation of transformers in hazardous locations,

except as modified by Articles 501-503.

Part II covers specific provisions applicable to different types of transformers. Although the

dry transformer is the most common seen in the field, special attention is given to the oil

filled transformer, because of the danger involved.

Part III covers transformer vaults; their installations and safe guards against fire.

Discuss the different types of transformers, voltages, and KVA.

APPLICATION:






ARTICLE 450

Level II

WORKSHEET

1. When grounding separately derived AC systems, all of the following are approved

grounding electrodes EXCEPT:

(a) The nearest available effectively grounded structural metal member of the

structure.

(b) The nearest available effectively grounded metal water pipe.

(c) A driven electrode, eight feet in length.

(d) The metallic raceway enclosing the conductors to the system.

2. In general, each transformer of 1000 volts or less is required to have individual primary

overcurrent protection. This overcurrent device is to be rated or set at not over which of

the following percentage of the primary current?

a. 125%

b. 150%

c. 200%

d. 300%

3. Which of the following is the maximum KVA dry-type transformer permitted to be

installed indoors with 12 inch separation from combustible material?

a. 35

b. 75

c. 112 ½

d. 125

4. A 50 KVA dry-type transformer is to be installed inside of an industrial building. In

general, which of the following is the minimum required distance of separation the

transformer must be from combustible material? .

a. 6 inches

b. 12 inches

c. 24 inches

d. 6 feet

5. What is the largest KVA dry type transformer that may be installed in the hollow spaces of

fire resistant ceiling?

a. 75 KVA

b. 112 1/2 KVA

c. 25 KVA

d. 50 KVA



ARTICLE 450

Level II

ANSWER KEY

1. d, The metallic raceway enclosing the conductors to the system 250.30(A)(4)

2. a, 125% T-450.3(B)

3. c, 112 1/2 450.21(A

4. b, 12 inches 450.21(A)

5. d, 50 KVA 450.13(B)


CAPACITORS

ARTICLE 460

Level II

OBJECTIVE:

After completing this lesson, each student should familiar with types of capacitors, where

they are normally used, and basic code requirements applicable to them.

INTRODUCTION:

Explain to student that this article is brief. Only a few minutes should be spent on this

article.


Cover code section briefly. Have capacitor available to show students and/or wiring

diagram of a capacitor. Cover Section 460.10, Grounding. Note that capacitor cases shall

be connected to the equipment grounding conductor.

APPLICATION:





CAPACITORS

ARTICLE 460

Level II

WORKSHEET

1. The residual voltage of a capacitor at or below 1000 volts shall be reduced to 50 volts,

nominal or less within how many minutes after the capacitor is disconnected from the

source of supply?

a. 1 minute

b. 2 minutes

c. 4 minutes

d. 5 minutes

2. The ampacity of capacitor circuit conductor at 1000 volts or less shall not be less than what

percent of the rated current of the capacitor?

a. 80%

b. 100%

c. 125%

d. 135%

3. Each capacitor of less than 1000 volts shall be provided with a nameplate giving all the

following except which of the following?

a. rated voltage

b. frequency

c. number of phases

d. maximum overcurrent device for capacitor


CAPACITORS

ARTICLE 460

Level II

ANSWER KEY

1. a, 1 minute 460.6(A)

2. d, 135% 460.8(A)

3. d, maximum overcurrent device for capacitor 460.12


STORAGE BATTERIES

ARTICLE 480

Level II

OBJECTIVE:

After completing this lesson each student should be: (1) acquainted with the NEC

requirements for storage batteries; (2) familiar with different types of batteries, such as

lead acid or alkaline type batteries.

INTRODUCTION:

A brief discussion of Article 480 in the code book.


Discuss code sections, different types of batteries, use handouts.

APPLICATION:





STORAGE BATTERIES

ARTICLE 480

Level II

WORKSHEET

1. Insulation shall be provided between groups of cells and shall have a minimum separation

between live battery parts of opposite polarity of:

a. 1 inch

b. 2 inches

c. 4 inches

d. 6 inches

2. Which of the following is correct concerning the location of racks for storing batteries?

I. Racks for storage of batteries may be made of fiberglass materials.

II. Provision shall be made for sufficient diffusion and ventilation of battery gases.

a. I only

b. II only

c. Both I and II

d. Neither I nor II


STORAGE BATTERIES

ARTICLE 480

Level II

ANSWER KEY

1. b, 2 inches 480.7

2. c, Both I and II 480.8(A)(2) & 480.9(A)


HAZARDOUS (CLASSIFIED) LOCATIONS - SPECIFIC

ARTICLE 510

Level II

OBJECTIVE:

After completing this lesson, each student should have a basic understanding of the code

requirements concerning hazardous locations.

INTRODUCTION:

Atmospheric concentrations of flammable liquids, gases, vapors or deposits of materials

which may readily ignite pose a hazard to occupancies that are covered in Articles 511

through 517.


Explain to the students that the rules of this article shall apply to wiring and equipment in

occupancies covered in Articles 511 through 517.

Article 514 covering gasoline dispensing and service stations has been covered in the level

I course and will not be covered in this course.

Also, note that in the event of unusual conditions in an occupancy, the authority having

jurisdiction shall judge with respect to the application of specific rules.

APPLICATION:






ARTICLE 510

Level II

WORKSHEET

1. What articles cover occupancies or parts of occupancies that are or may be hazardous

because of atmospheric concentration of flammable liquids, gases, and vapors?



ARTICLE 510

Level II

ANSWER KEY

1. 510.1 Articles 511 through 517


COMMERCIAL GARAGES

ARTICLE 511

Level II

OBJECTIVE:

Each student should become familiar with the definition as well as the wiring methods and

materials for use in a commercial garage.

MATERIALS NEEDED:

Show samples of Raceways, Seal-off fitting, explosion proof equipment.

INTRODUCTION:

Let students know this is a very serious matter in the field and that you will cover this

section in detail (read Article 510 and review). Other codes sections are closely related,

such as 500, 501, 502.


Discuss Articles 511, 501, 502, cover 511 in detail. Use handouts to illustrate certain areas

in garages, to insure students know or can identify certain areas of classification in garages.

Be sure students are familiar with wiring methods and materials for this installation. The

article is a very popular installation in the field.

APPLICATION:





COMMERCIAL GARAGES

ARTICLE 511

Level II

WORKSHEET

1. In a commercial garage each floor area, without ventilation, up to a level of 18 inches

above the floor shall be considered to be which of the following locations?

a. Class I, Div. I

b. (b)Class I, Div. 2

c. Class II, Div. I

d. Class II, Div. 2

2. All of the following methods or materials are approved for wiring above the Class I

location in garages except which of the following?

a. rigid non-metallic conduit

b. electrical non-metallic tubing

c. non-metallic sheathed cable

d. MI type cable

3. Lamps and lampholders for fixed lighting that are installed over vehicle service lanes shall

be located no less than what distance above the floor, unless the lamp is of the totally

enclosed type?

a. 8 feet

b. 10 feet

c. 12 feet

d. 14 feet

4. When wiring commercial garages, which of the following is correct?

I. All 125 volt, 15 and 20 amp receptacles for electrical hand tools and portable

lighting devices shall have ground-fault protection for personnel.

II. All 240 volt receptacles in garage shall have ground-fault protection for

personnel.

a. I only

b. II only

c. Both I and II

d. Neither I nor II


COMMERCIAL GARAGES

ARTICLE 511

Level II

ANSWER KEY

1. b, Class I, Div. 2 511.3(B)(3)(1)

2. c, non-metallic sheathed cable 511.7(A)(1)

3. c, 12 feet 511.7(B)(1)(b)

4. a, I only 511.12


THEATERS AND SIMILAR LOCATIONS

ARTICLE 520

Level II

OBJECTIVE:

After completing this lesson, each student should have a basic understanding of the

requirements of Article 520 as related to Theaters and Similar Locations.

MATERIALS NEEDED:

Slides or pictures of theater switchboards and equipment.

INTRODUCTION:

This article covers the requirements for Theaters and Similar Locations. Equipment such

as Fixed Stage Switchboards and stage equipment, Portable Stage Switchboards and stage

equipment and dressing rooms are included.


This article covers the wiring methods and equipment in buildings used for dramatic,

musical motion picture, projection and television studios, which have assembly areas.

Part I covers general wiring requirements. Motion Picture Projectors, Emergency systems

and Sound Reproduction are covered in their applicable articles (540, 640, 700). Emphasis

should be placed on wiring methods and note should be made of the waiver of the 30

conductor limitation for auxiliary gutters and wireways.

Part II covers Fixed Stage Switchboards. Special emphasis should be placed on dimmers,

types of switchboards and the requirements applicable to each. Section 520.27 covers

Stage Switchboard feeders.

Part III covers Fixed Stage Equipment such as Footlights, Border and Proscenium

Sidelights. Requirement for footlights, border and proscenium sidelights should be

covered. Cover the requirement for Receptacles, Curtain motors and Flue damper controls.

Part IV covers Portable Switchboard on stage. Emphasis should be placed on requirements

for Road and Show Connection Panel (a type of Patch Panel). Supply overcurrent

protection, and feeders for portable switchboards are covered under 520.51, 52 & 53.

Emphasize Circuit protection (D) and supply conductors (H). Section (K) covers

protection of supply conductors and connectors.

Part V covers Portable Stage Equipment. Cover the requirements for portable plugging

boxes and bracket fixture wiring. Attention should be given to conductors for portable

stage equipment.


Part VI covers Dressing rooms. Special emphasis should be placed on he prohibition of

pendant lampholders, the requirements for lamp guards and the required switches (520-71,

72, 73).

Part VII covers Grounding.

APPLICATION:






ARTICLE 520

Level II

WORKSHEET

1. The permitted fixed wiring method of theaters shall be which of the following?

a. metal raceways

b. nonmetallic raceways encased in at least 2” concrete

c. type MI or MC cable

d. all of the above

2. Footlights, border lights, and proscenium sidelights shall be arranged so that no branch

circuit will carry a load exceeding which of the following?

a. 15 amperes

b. 20 amperes

c. 30 amperes

d. 100 amperes

3. The supply to a portable switchboard shall be by means of which of the following?

a. rigid metal conduit

b. NM cable

c. nonmetallic conduit

d. extra hard usage cords or cables

4. Which of the following is/are correct concerning lamps and/or lampholders in dressing

rooms?

I. Pendant lampholders shall not be installed in dressing rooms.

II. All lights in dressing rooms shall be controlled by wall switches installed in the

dressing room.

a. I only

b. II only

c. Both I and II

d. Neither I nor II


5. In high temperature applications concerning portable stage equipment, which of the

following is correct?

I. A special assembly of conductors shall be permitted to be employed in lieu of flexible

cord if the individual wires are rated not less than 125°C and the outer sleeve is glass

fiber with a wall thickness of at least .025 inches.

II. No special assembly is permitted.

a. I only

b. II only

c. Both I and II

d. Neither I nor II



ARTICLE 520

Level II

ANSWER KEY

1. d, all the above 520.5

2. b, 20 amperes 520.41

3. d, extra hard usage cords or cables 520.53(H)(1)

4. c, Both I and II 520.71 & 520.73

5. a, I only 520.68(A)(3)


CONTROL SYSTEMS FOR PERMANENT AMUSEMENT ATTRACTIONS

ARTICLE 522

LEVEL II

OBJECTIVE:

After completing this lesson, each student should be familiar with the requirements of Article

522.

MATERIALS:

Examples of control circuit power sources and control circuit conductors for electrical

equipment, including associated control wiring in or on all structures that are an integral part of a

permanent amusement attraction.

INTRODUCTION:

This article covers the requirement for Control Systems for Permanent Amusement Attractions.


Part I covers the scope of requirements for installation of control circuit power sources and

control circuit conductors for electrical equipment, including associated control wiring in or on

all structures that are an integral part of a permanent amusement attraction. There are specific

definitions that are integral with this Section. Note the references to "ride devices" and the

specific relevance to this Article and its reference to the application of other Code Articles. Part

II covers the installation requirements for power sources, circuits and wiring methods. Part III

covers the control circuit wiring methods, conductor sizing, overcurrent, and location, grounding

and wet location requirements.

APPLICATION:






ARTICLE 522

LEVEL II

WORKSHEET

1. What is the ampacity of a #18 AWG copper conductor used in a control circuit at a permanent

amusement attraction?

a. 7 amps

b. 9 amps

c. 11 amps

d. 15amps

2. Control voltage shall be a maximum of which of the following.

a. 150 volts ac volts to ground

b. 300 volts dc volts to ground

c. Neither a nor b

d. Both a and b

3. Non–power-limited control circuits shall not exceed which of the following?

a. 150 volts

b. 250 volts

c. 1,000 volts

d. 300 volts



ARTICLE 522

LEVEL II

ANSWER KEY

1. a, 7 amps Table 522.22

2. d, both a and b 522.5

3. d, 300 volts 522.10(B)


CARNIVALS, CIRCUSES, FAIRS, AND SIMILAR EVENTS

ARTICLE 525

LEVEL II

OBJECTIVE:

After completing this lesson, each student should be familiar with the requirements of Article

525.

MATERIALS:

Pictures of power supply equipment.

INTRODUCTION:

This article covers the requirement for Carnivals, Circuses, Fairs, and Similar Events.


Section I covers the general requirements and other articles.

Section II covers power sources.

Section III covers wiring methods.

Section IV covers grounding and bonding.

APPLICATION:






ARTICLE 525

LEVEL II

WORKSHEET

1. Which article applies to permanent structures?

a. Article 519

b. Article 520

c. Article 810

d. Article 518

2. Each portable structure shall be provided with a disconnect means located within sight

and within what distance of the operator’s station.

a. 50 ft

b. 25 ft

c. 10 ft

d. 6 ft

3. The ground-fault circuit interrupter shall be permitted to be an integral part of the

attachment plug or located within what distance of the attachment plug.

a. 6 inches

b. 12 inches

c. 18 inches

d. 10 inches



ARTICLE 525

LEVEL II

ANSWERS

1. d, Article 520 and Article 518 525.3(B)

2. d, 6 ft. 525.21(A)

3. b. 12 inches 525.23(A)


MOTION PICTURE PROJECTORS

ARTICLE 540

Level II

OBJECTIVE:


areas in motion picture projectors.

INTRODUCTION:

This article applies to projection rooms, projectors and their associated equipment that

develop hazardous gases.


Professional projectors are those using 35 or 70 millimeter film with a minimum of 1

3/8” and have on each edge 5.4 perforations per inch. All others are non-professional.

Projection rooms shall be of permanent construction approved for the type of building

with glass over the projection port.

Those items listed in 540.11(A) shall be located in a separate room or located so that arcs

or sparks will not get to the film. Switches and overcurrent devices shall not be located

in projection rooms.

Picture projectors, spotlights, floodlights and similar equipment shall have a clear work

space of 30".

Conductors supplying outlets for arc or Xenon projectors of the professional type shall

not be smaller than #8.

Conductors used on all lamps or other equipment with operating temperature over 50o C

shall have insulation designed for no less than 200 degrees Centigrade.

Flexible cords are to be hard usage type cords.

Projector enclosures for arc and Xenon lamps, and rectifiers, transformers, etc. shall be

approved.

Non professional equipment shall be approved but not required to be in a

projection room.


APPLICATION:





MOTION PICTURES PROJECTORS

ARTICLE 540

Level II

WORKSHEET

1. Professional Projectors must use which of the following types of film?

a. 35 millimeter

b. 70 millimeter

c. 120 millimeter

d. Both a and b

2. Where nitrate film is used, motor generator sets, transformers, rectifiers, rheostats, and

Similar equipment for the supply or control of current to projection or spotlight

equipment shall be located in which of the following?

a. A separate room.

b. A film closet.

c. A film vault.

d. A projector vault.

3. Each motion picture projector, floodlight, spotlight, or similar equipment shall have clear

working space not less than

a. 30 inches wide on each side and at the rear thereof.

b. 48 inches wide on each side and at the rear thereof.

c. 52 inches wide on each side and at the rear thereof.

d. 60 inches wide on each side and at the rear thereof.


MOTION PICTURE PROJECTORS

ARTICLE 540

Level II

ANSWER KEY

1. d, both a and b (35, 70) 540.2

2. a, a separate room 540.11(A)

3. d, 30 inches wide 540.12


MARINAS AND BOATYARDS

ARTICLE 555

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the general

requirements of electrical installation in Marinas and Boatyards.

INTRODUCTION:

The number of installations covered by Article 555 is increasing rapidly and the

importance of proper understanding and application of these safety regulations cannot be

over emphasized. There have been a number of electrocutions on such installations in

North Carolina that could have been avoided provided applicable safety requirements had

been incorporated in the original installation. Maintenance of these installations is also a

very important part of the "safety package."

Many of the recreational facilities covered in the scope of Article 555 will be found in

locations where corrosion is a very difficult problem. Samples of outdoor equipment

which has been designed and listed for such use will be helpful when evaluating proper

application of the necessary components.


The scope and application of other Articles in Section 555.1 and 555.2 need to be

reviewed with the students. Also the requirement included in Section 210.8 (B).

The requirements in Section 555.19 cover receptacles which are divided into two classes

of use; 1. Those which provide shore power to the boats and 2. Those which are for use

in maintenance and other purposes. The safety regulation for each is different and

consequently must be thoroughly understood.

Section 555.12, and 555.17 include safety requirements pertaining to the minimum sizing

requirements for branch circuits, feeders and services.

Permitted wiring methods are given in Section 555.13 and should be thoroughly

discussed.

A great deal of emphasis should be placed on covering the grounding requirements

included in Section 555.15 Applicable requirements in Article 250 should also be

reviewed.

Wiring over and under navigable water is subject to the approval of governmental

agencies, such as the Coast Guard.


The requirements included in Sections 555.21 pertaining to Gasoline Dispensing and

should be reviewed carefully.

APPLICATION:






ARTICLE 555

Level II

WORKSHEET

1. Which of the following is/are correct concerning shore power receptacles installed at a

marina or boatyard?

I. All shore power receptacles rated 30 to 50 amperes shall be of locking and grounding

type.

II. All shore power receptacles shall be protected by ground-fault circuit interrupter.

a. I only

b. II only

c. Both I and II

d. Neither I or II

2. Which of the following is/are correct concerning 125 volt, 15 and 20 amp convenience

type receptacles installed at a marina or boatyard?

I. All 125 volt, 15 and 20 amp convenience receptacles shall be protected by ground-

fault circuit interrupters.

II. All 125 volt, 15 and 20 amp convenience receptacles shall be of locking and

grounding type.

a. I only

b. II only

c. Both I and II

d. Neither I or II

3. Twenty shore power receptacles rated 20 amperes and 120 volts will be supplied from

one panel. The minimum ampacity for the 120/240 volt feeder is:

a. 140 amps

b. 280 amps

c. 200 amps

d. 400 amps


4. When grounding metal boxes and cabinets at a Marina which of the following is the

minimum size of equipment grounding conductor permitted?

a. #142 insulated copper

b. #12 insulated aluminum

c. #12 insulated conductor

d. #102 bare copper

5. Under what conditions can service equipment be installed on a floating dock or

marina?

a. Floating Piers

b. Boat Docks

c. Marinas

d. None of these



ARTICLES 555

Level II

ANSWER KEY

1. a 555.19(A)(4)

2. a 555.19(B)(1)

3. a, 20 x 20 x 120 = 48,000 x 70% = 33,6 00/240 V = 140 amps Table 555.12

4. c 555.15(C)

5. d 555.7


MANUFACTURED WIRING SYSTEMS

ARTICLE 604

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the uses and construction of

manufactured wiring systems.

INTRODUCTION:

This article applies to field-installed wiring using off-site manufactured subassemblies for

branch circuits, remote-control circuits, signaling circuits and communication circuits in

accessible areas. Also, a manufactured wiring system is defined as: a system containing

component parts that are assembled in the process of manufacture and cannot be inspected at

the building site without damage or destruction to the assembly and used for the connection of

luminaires, utilization equipment, continuous plug-in type busways and other devices.


These systems are permitted to be used in accessible and dry locations and in plenums and

spaces used for environmental air when appropriate. Also, installation must comply with

Section 300.22. Review the many articles that affect or limit the use of such systems.

Stress the specifications of cable [Section 604.6(A)] and conduit types [Section 604.6(B)] and

review the specifications for receptacles and connectors in Section [604.6 (C)]

Any unused outlet should be capped to effectively close the connector openings.

APPLICATION:






ARTICLE 604

Level II

WORKSHEET

1. Manufactured wiring systems shall be permitted in which of the following?

a. Accessible and dry locations.

b. Ducts and plenums.

c. Air-handling spaces where listed for this application.

d. All of the above.

2. Cable shall be listed armored cable or metal-clad containing nominal 600-volt:

a. No. 10 AWG copper insulated conductors with a bare No. 12 AWG

copper equipment grounding conductor.

b. No. 12 AWG copper insulated conductors with a bare No. 12 AWG


c. No. 12 AWG aluminum insulated conductors with a bare No. 12 AWG

aluminum equipment grounding conductor.

d. No. 12 AWG copper insulated conductors with a bare No. 14 AWG


3. Without exception conduit shall be listed flexible metal conduit containing nominal 600-

volt:

a. No. 12 AWG copper insulated conductors with an insulated or bare No. 12

AWG copper equipment grounding conductor.

b. No. 12 AWG copper insulated conductors with an insulated or bare No. 10


c. No. 10 AWG copper insulated conductors with an insulated or bare No. 8


d. No. 10 AWG copper insulated conductors with an insulated or bare No. 12


4. Which of the following is/are correct concerning receptacles and connectors in

manufacturing wiring systems?

I. Receptacles and connectors shall be locking type.

II. Receptacles and connectors shall be identified for this purpose.

a. I only

b. II only

c. Both I and II

d. Neither I nor II



ARTICLE 604

Level II

ANSWER KEY

1. d, all of the above 604.4

2. b 604.6(A)(1)

3. a 604.6(A)(2)

4. c 604.6(BC)


ELEVATORS, DUMBWAITERS, ESCALATORS, AND MOVING WALKS

ARTICLE 620

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar the requirements of Article 620

for Elevators, Dumbwaiters, Escalators and Moving Walks.

INTRODUCTION:

This article covers the installation of electric equipment and wiring used in connection with

elevators, dumbwaiters, escalators and moving walks.


Part I covers definitions; voltage limitations for operating control and signaling circuit and for

motors, brakes and motor generator sets; and working clearances.

Part II covers the conductors installed for use with equipment covered in Article 620. Place

emphasis on the flame retardant requirement for insulation of conductors and the permitted

types. Also cover the minimum size conductors as covered in Article 620.12 & 13. Go

through an overhead of figure 620.13.

Part III covers the permitted wiring methods in this article. Place emphasis on these

requirements. Also place emphasis on the branch circuits for car lighting, receptacle(s),

ventilation, branch circuit for machine room machinery spaces, lighting and receptacles; and

branch circuit for hoistway pit lighting and receptacle(s).

Part IV covers the installation of conductors. Emphasize the different limitations for wireways

and auxiliary gutters. Special emphasis should be placed on 620.37 Wiring in Hoistways; uses

permitted and lighting protection. Refer to Article 511 for wiring in Hazardous Locations.

Part V covers Traveling Cables.

Part VI covers the Disconnecting Means and Control. Special emphasis should be placed on

the requirements for a single means for disconnecting all ungrounded conductors for each unit

including the control value operating magnets. This disconnect shall not disconnect the

required branch circuits in 620.22 through 620.24. The location of this disconnect shall be

where readily accessible to qualified persons.

Part VII covers Overcurrent Protection. Overcurrent protection for operating devices and

controls shall be provided as covered in Articles 725.43 and 725.45 and for motors in Article

430.33. Highlight this article is one of those within the NEC (others include Articles 517, 700,

and 708) that mandate selective coordination and is applicable where more than one machine is

supplied by a single feeder.


Part VIII covers the Machine Room. This room shall be secured. Make note of where motor

controllers and driving machines can be located.

Part IX covers grounding and refers to Article 250 and part X covers emergency and standby

power systems.

APPLICATION:






ARTICLE 620

Level II

WORKSHEET

1. In general, the nominal voltage for operating control and signaling circuits for elevators

shall not exceed which of the following?

a. 150 volts

b. 250 volts

c. 300 volts

d. 600 volts

2. The minimum size of conductors used for elevator traveling cables when used for

lighting and installed in parallel is which of the following provided the ampacity is

equivalent to at least #14 AWG wire?

a. #14 AWG

b. #16 AWG

c. #20 AWG

d. #24 AWG

3. A separate circuit is required to supply which of the following in an elevator car?

a. car lights

b. receptacle(s)

c. car ventilation

d. all the above

4. Feeders supplying power to elevators and dumbwaiters shall meet which of the

following?

A) shall be installed inside the hoistway.

B) shall be permitted within an existing hoistway without splices by special permission.

a. A only

b. B only

c. both A & B

d. neither A or B


5. Which statement is not true concerning disconnect means for the main power supply:

a. Single means provided to disconnect all ungrounded power supply

conductors for each unit.

b. Disconnect be so designed that no pole can be operated independently

c. Where multiple driving machines are connected to a single elevator, there shall be

one disconnect to disconnect the motor and control valve and operating magnets.

d. The disconnecting means for the main power supply conductors shall

disconnect the branch circuit for a car light.

6. Which of the following is/are correct concerning the elevator equipment disconnecting

means?

I. The disconnecting means shall be installed in a room set aside for that purpose.

II. The room for the disconnecting means does not have to be secured

against unauthorized access.

a. I only

b.II only

c. Both I & II

d.Neither I or II



ARTICLE 620

Level II

ANSWER KEY

1. c, 300 volts 620.3

2. c, #20 620.12(A)(1)

3. d, all of the above 620.22(A)

4. b, B only 620.37(C)(1)

5. d, The disconnecting means for the main power

supply conductors shall disconnect the branch

circuit for a car light. 620.51

6. a, I only 620.71


ELECTRIC VEHICLE CHARGING

SYSTEM EQUIPMENT

ARTICLE 625

LEVEL II

OBJECTIVE:

After completing this lesson, each student should be familiar with the requirement for equipment

and wiring, external to an electric vehicle, that connect an electric vehicle to a supply of

electricity.

INTRODUCTION:

This Article covers the equipment and wiring requirements for installation of equipment and

devices related to electric vehicle charging.


Make note of wiring method 625.10 Equipment Construction , 625.40 Overcurrent

Protection, Also make note of 625.42 Disconnecting Means

APPLICATION:






SYSTEM EQUIPMENT

ARTICLE 625

LEVEL II

WORKSHEET

1. Which one of the following electric vehicles would be covered under Article 625.

a. Golf Carts

b. Electric Motorcycles

c. Passenger Buses

d. Boats

2. All electrical materials, devices, fittings, and associated equipment shall meet which of

the following?

a. Made in USA

b. Approved by local inspector

c. Approved for that vehicle only

d. Listed or labeled

3. An electric vehicle supply connector shall be provided with a grounding pole

that shall be configured to connect with the mating inlet in which of the following

manners?

a. first to make and last to break

b. the same make and type

c. in the same location

d. connect vertically

4. Overcurrent protection for feeders and branch circuits supplying electric vehicle supply

equipment shall be sized at which of the following?

a. 80%

b. 115%

c. 125%

d. 75%

5. For electric vehicle supply equipment rated more than 60 amperes or more than 150 volts

to ground, the disconnecting means shall meet which of the following?

a. Be installed in an accessible location

b. Be installed not less than 18 in. and not more than 4 ft. above floor level.

c. Be rated at 115% of connected load

d. Be installed in a readily accessible location.



SYSTEM EQUIPMENT

ARTICLE 625

LEVEL II

ANSWER KEY

1. c, passenger buses 625.2

2. d, listed or labeled 625.5

3. a, first to make and last to break 625.10 F

4. c, 125% 625.40

5. d, be installed in a readily accessible location 625.42


ELECTRIC WELDERS

ARTICLE 630

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar the requirement for electric arc

welding, resistance welding apparatus and similar welding equipment.

MATERIALS NEEDED:

Slides or transparencies of nameplates from several types of welders as well as Transparencies

of Duty Cycle tables.

INTRODUCTION:

This article covers the requirements for AC Transformers, DC Rectifier Welders, Motor

Generator Arc Welders, Resistance Welders and Welding Cable.


Part II covers the requirements for Arc Welders. Go over the requirements for sizing the

conductors that supply these welders. Emphasize the "duty cycle" for an individual and a

group of welders. Cover the requirements for overcurrent protection and disconnecting means.

Part III covers the requirements for Resistance Welders. Go over the requirements for sizing

the conductors, overcurrent protection and disconnecting means. Emphasize calculations using

"duty cycle"

Part IV covers the requirements for Welding Cable.

APPLICATION:





ELECTRIC WELDERS

ARTICLE 630

Level II

WORKSHEET

1. What ampacity conductors would be required for an AC transformer type welder with a

primary current rating of 100 amps and a duty cycle of 50?

a. 100 amperes

b. 91 amperes

c. 88 amperes

d. 71 amperes

2. Four AC transformer type welders rated 50, 35, 30, and 20 amperes are connected on the

same circuit. The circuit conductors shall be considered ample when rated which of the

following minimum amperes?

a. 135 amperes

b. 124 amperes

c. 116 amperes

d. 97 amperes

3. Which of the following is the supply conductor size for a resistance welder with a

primary current of 100 amperes and a duty cycle of 30% if the supply conductor is

THW copper?

a. # 4

b. # 6

c. # 8

d. # 10


ELECTRIC WELDERS

ARTICLE 630

Level II

ANSWER KEY

1. d. 71 amperes Table [630.11(A)(2)

Duty cycle is 50 which has multiplier of .71 times the rated primary current 100 equals

71

amperes.

2. b. 124 amperes [630.11(B)]

Use 100% of the two largest 50 + 35 x 100% = 85 Amperes

Use 85% of the third largest 30 x 85% = 25 Amperes

Use 70% of the fourth largest 20 x 70% = 14 Amperes

124 Amperes

3. b. 55 amperes [630.31(A)(2)] and 310.15( B) (16)

Multiplier for 30% duty cycle is .55 times 100 Amperes = 55 Amperes


AUDIO SIGNAL PROCESSING, AMPLIFICATION,

AND REPRODUCTION EQUIPMENT

ARTICLE 640

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar the requirement for equipment

and wiring for sound recording and similar equipment.

INTRODUCTION:

This Article covers the equipment and wiring requirements for sound-recording and

reproduction, centralized distributions of sound, public address, speech-input system and

electronic organs.


Note that this Article refers to other Sections of the NEC. Note the exceptions that modify

these other Sections in 640.2, 3, and 4. Note the requirement concerning conductors, flexible

cords and storage batteries. Note the circuit overcurrent protection requirements.

APPLICATION:







ARTICLE 640

Level II

WORKSHEET

1. All wiring not connected to the premises shall comply with:

a. Chapters 1-4

b. Article 480

c. Article 647

d. Article 725

2. Flexible cords and cables to and between permanent audio systems shall comply with

which of the following articles?

a. Article 725.

b. Article 110

c. Article 647

d. Article 310.16

3. Wireways and auxiliary gutters shall be grounded and bonded in accordance with the

requirements of Article 250. Where the wireway or auxiliary gutter does not contain

power-supply wires, the equipment grounding conductor shall not be required to be larger

than which of the following?

a. # 14 AWG

b. # 12 AWG

c. # 10 AWG

d. # 6 AWG

4. In portable audio systems, installation shall comply with which of the following Articles?

a. 480

b. 647

c. 300

d. 400




ARTICLE 640

Level II

ANSWER KEY

1. d, Article 725 640.9 (A)(3)

2. a. Article 725 640.21(C)

3. a. # 14 AWG 640.7(A)

4. d, Article 400 640..42(C)


INFORMATION TECHNOLOGY EQUIPMENT

ARTICLE 645

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar the requirements concerning

electronic computer/data processing equipment and system.

INTRODUCTION:

This article covers equipment, power-supply wiring, equipment interconnecting wiring, and

grounding of electronic computer/data processing equipment and systems, including electronic

computer/data processing equipment and systems used as a terminal unit in an electronic

computer/data processing room.


Branch circuit conductors that have data processing units on the line shall have an ampacity not

less than 125 percent of the total connected load. (645.5)

Review the requirements of connecting cables of data processing systems. Also, note that

when such cables are run on the floor that they shall be protected against physical damage.

[645.5(C)]

Discuss the conditions under which power cables, communication cables, etc. shall be allowed

under raised floors. [645.5(D)]

Explain the requirements for disconnecting means in Section 645-10 and note that there may

be a single means permitted to control both the electronic equipment and the air conditioning

system.

All exposed metal parts of a data processing system shall be grounded in accordance with

Article 250(D). A data processing unit designed to be supplied by a branch circuit shall be

provided with a manufacturer's nameplate which includes the rating in volts, operating

frequency and total load in amperes.

APPLICATION:






ARTICLE 645

Level II

WORKSHEET

1. Branch circuit conductors that have data processing units on the line shall have an

ampacity not less than what percent of the total connected load.

a. 80%

b. 100%

c. 115%

d. 125%

2. If connecting cables of data processing systems are run on the surface of the floor they

shall be protected against which of the following?

a. Moisture damage

b. Physical damage

c. Overheating from lighting

d. Ultra-violet damage

3. The branch circuit supply conductors to receptacles under raised floors shall be

In which of the following?

a. rigid metal conduit

b. metal wireway

c. flexible metal conduit

d. all of the above

4. Which of the following is/are correct concerning the disconnecting means for electronic

equipment in a data processing room?

I. The disconnecting means shall be readily accessible to the operator at the principal exit

doors.

II. A single means to control both the electronic equipment and air-conditioning system

shall be permitted.

a. I only

b. II only

c. Both I and II

d. Neither I nor II



ARTICLE 645

Level II

ANSWER KEY

1. d, 125% 645.5(A)

2. b, physical damage 645.5(B & C)

3. d, all of the above 645.5(D)(2)

4. c, Both I and II 645.10


PIPE ORGANS

ARTICLE 650

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with regulations concerning the

energy source, insulation, conductors, and installation of conductors and overcurrent protection

of organs.

INTRODUCTION:

This article covers the electric circuits and parts of electrically operated organs which are used

for control of the sounding apparatus and keyboards. Such organs shall also comply with the

appropriate provisions of Article 640.


Discuss the source of energy requirements for organs. (650.3)

Explain the insulation requirements for grounding or specific parts. Conductors shall be No.

26 or larger and the common-return conductor shall be No. 14 or larger. The insulation of such

conductors shall be of rubber, thermoplastic, cotton, or silk insulation. Note the exception for

the insulation of the common return conductors.

Discuss the conductors to be cabled and cable coverings in Section [650.5(C & D)].

Cables may be attached directly to the organ structure without insulating supports, but may not

be placed in contact with other conductors. (650.6)

All conductors shall be arranged so that they are protected by an overcurrent device rated at not

over 6 amperes. (650.7)

APPLICATION:





PIPE ORGANS

ARTICLE 650

Level II

WORKSHEET

1. The source of energy shall have a potential of not over which of the following?

a. 15 volts ac

b. 15 volts dc

c. 30 volts ac

d. 30 volts dc

2. Conductors shall be not less than which of the following for electronic signal circuits?

a. 28 AWG

b. 26 AWG

c. 14 AWG

d. 30 AWG

3. Conductors shall have which of the following type of insulation?

a. Thermoplastic

b. Thermosetting

c. Neither a or b

d. Either a or b

4. Where not installed in metal raceway, the covering shall be which of the following?

a. Resistant to insects.

b. Resistant to Flame spread

c. Resistant to Ultra-violet light

d. Resistant to Thermal overload

5. Cables shall be securely fastened in place and shall be permitted to be attached directly

to the organ structure without which of the following?

a. Insulating supports.

b. Conductor supports.

c. Thermal overload.

d. Overload Resistors.


PIPE ORGANS

ARTICLE 650

Level II

ANSWER KEY

1. d, 30 volts dc 650.3

2. a, 28 AWG 650.5(A)

3. d, Either a or b 650.6(B)

4. d, Resistant to flame-spread 650.5(D)

5. a, Insulating supports. 650.7


INDUSTRIAL MACHINERY

ARTICLE 670

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar the definition, nameplate

data, overcurrent protection, and supply conductors for industrial machinery.

INTRODUCTION:

Take this time to go over the definitions of industrial machinery (machine) and industrial

manufacturing system.


A permanent nameplate shall be attached to the control equipment enclosure or machine and

shall be plainly visible after installation. The nameplate shall include the following

information:

(1) Supply voltage, phase, frequency, and full-load current

(2) Maximum ampere rating of the short-circuit and ground-fault protective device

(3) Ampere rating of largest motor, from the motor nameplate, or load

(4) Short circuit current rating of the machine industrial control panel based on one of

the following:

a. Short circuit current rating of a listed and labeled machine control enclosure or

assembly

b. Short circuit current rating established utilizing an approved method

FPN: UL 508A-2001, Supplement SB, is an example of an approved method.

(5) Electrical diagram number(s) or the number of the index to the electrical drawings

[670.3(A)]

Discuss the rating of the full-load current for different combinations of motors. The machine

shall be marked "overcurrent protection provided at machine supply terminals," when

overcurrent protection is provided in accordance with Section [670.4(B)].

Discuss how the size of supply conductors shall be determined as indicated by Section

[670.4(A)] Also cover fine print notes (FPN).

As far as overcurrent protection is concerned, a machine shall be considered as an individual

unit and therefore shall be provided with a disconnecting means. Discuss the requirements for

disconnecting means for industrial machinery.


APPLICATION:






ARTICLE 670

Level II

WORKSHEET

1. This article covers which of the following pertaining to the supply conductors to

industrial machinery?

a. The definition of.

b. The size and overcurrent protection

c. The nameplate data for.

d. All of the above

2. Machine nameplate data should include which of the following except?

a. Supply voltage, phase, frequency, and full-load current

b. Maximum ampere rating of the short-circuit and ground-fault protective

device.

c. Ampere rating of largest motor, from the motor nameplate, or load

d. Fault current rating of the listed control panel.

3. The supply conductor shall have an ampacity not less than what percent of the full-load

current

rating of all heating loads plus what percent of the full-load current rating of the highest

rated motor plus the sum of the full-load current ratings of all other connected motors

which may be in operation at the same time?

a. 100 %, 125%

b. 125%, 100 %

c. 100%, 100 %

d. 125%, 125%



ARTICLE 670

Level II

ANSWER KEY


2. d, fault current rating of the control panel 670.3

3. d, 125%, 125% 670.4


ELECTRICALLY DRIVEN OR CONTROLLED IRRIGATION MACHINES

ARTICLE 675

Level II

OBJECTIVE:

After completing this lesson, each student should understand the definition of irrigation

machines and definitions related to the equipment.

MATERIALS NEEDED:

Samples of conductor used, types of disconnects.

INTRODUCTION:

Explain to students that you will briefly cover the article, cover the most important sections.

This type of installation is not seen often, and a short period of time should be spent on the

article.


Discuss code sections, touch on wiring methods and materials used. Discuss certain code

sections that would be found more often in field, for example: types of wires permitted, sizes

of conductors, disconnecting mean and grounding of equipment.

APPLICATION:

If time will allow, let the class have time to answer the questions on the worksheet.





ARTICLE 675

Level II

WORKSHEET

1. The cable used to interconnect enclosures on the structure of an irrigation machine shall

be of a type approved for use in wet locations and have a minimum temperature rating

of?

a. 60° C

b. 75° C

c. 85° C

d. 90° C

2. The cables used to interconnect enclosures on irrigation equipment shall be supported at

intervals not to exceed which of the following?

a. 2 feet

b. 3 feet

c. 4 feet

d. 6 feet

3. The main disconnecting means for irrigation equipment shall be a maximum distance

from the equipment of which of the following?

a. 10 feet

b. 25 feet

c. 50 feet

d. In sight

4. Cords used on irrigation machines shall have an equipment grounding conductor as an

integral part of the cord, the equipment grounding conductor shall not be smaller than?

a. largest cord supply conductor

b. #16 copper

c. #14 copper

d. sized according to 250.122


5. A disconnecting means in sight from the machine and 20 feet away shall meet which of

the following requirements?

I. Shall be capable of being locked in the open position.

II. Shall be readily accessible.

a. I only.

b. II only.

c. Neither I or II

d. Both I and II



ARTICLES 675

Level II

ANSWER KEY

1. b 675.4(A)

2. c 675.4(C)

3. d 675.8(B)

4. a 675.13

5. d 675.8(B)


INTEGRATED ELECTRICAL SYSTEMS

ARTICLE 685

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the location of overcurrent

devices, direct-current system grounding, and ungrounded control circuits of integrated

electrical systems.

INTRODUCTION:

An integrated electrical system is a unitized segment of an industrial wiring system where all

of the following conditions are met:

(1) An orderly shutdown is required to minimize personnel hazard and equipment damage.

(2) The conditions of maintenance and supervision ensure that qualified persons service the

system. The name(s) of the qualified person(s) shall be kept in a permanent record at the

office of the establishment in charge of the completed installation.

A person designated as a qualified person shall possess the skills and knowledge related

to the construction and operation of the electrical equipment and installation and shall

have received documented safety training on the hazards involved. Documentation of

their qualifications shall be on file with the office of the establishment in charge of the

completed installation.

(3) Effective safeguards acceptable to the authority having jurisdiction are established and

maintained


Explain how overcurrent devices shall be accessible but mounted at heights that assure security

form operation by non-qualified personnel. Note that two-wire direct-current circuits shall be

permitted to be ungrounded. (685.12)

Explain that, where operational continuity is required, control circuits of 150 volts or less from

separately derived systems shall be permitted to be ungrounded. (685.14)

APPLICATION:



If time will allow, correct the worksheets and discuss the results



ARTICLE 685

Level II

WORKSHEET

1. Which of the following statement is correct regarding integrated electrical systems?

I. Two-wire direct current circuits shall not be permitted to be ungrounded.

II. Overcurrent devices shall be permitted to be accessible with mounting heights allowed to

assure security from operation by unqualified personnel.

a. I only

b. II only

c. I and II

d. neither

2. Where operational continuity is required, control circuits of which of the following volts or

less from separately derived systems shall be permitted to be ungrounded.

a. 100

b. 150

c. 175

d. 200



ARTICLE 685

Level II

ANSWER KEY

1. b 685.10, 685.12

2. b 685.14


FIRE PUMPS

ARTICLE 695

LEVEL II

OBJECTIVE:

After completing this lesson, each student should the definition, overcurrent protection and

supply conductor for fire pumps.

INTRODUCTION:

Note to students the application of other Articles (Chapters 1, 2, 3, and 4). For level II you

should cover section 695.3 and 695.14.


Explain to students the purpose of fire pumps and how they should operate under emergency use.

Review chapters 1-4 and how they relate to fire pumps.

Review section 695.3 on power supplied to electric motor-driven fire pumps. Make note to

review exception.

Review section 695.6; supply conductor, wiring method and conductors.

APPLICATION:



If time will allow, correct the worksheets and discuss the results


FIRE PUMPS

ARTICLE 695

LEVEL II

WORKSHEET

1. Power shall be permitted to be supplied to the electric motor driven fire pump by:

(A) Service

(B) On-Site Generation

a. A only

b. B only

c. Neither A or B

d. Both A and B

2. A disconnecting means and overcurrent protective device(s) shall be permitted to be

installed between the power supply and listed fire pump controller. A placard shall be

externally installed on the disconnecting means stating “FIRE PUMP

DISCONNECTING MEANS”. The letters shall be at least which of the following in

height?

a. 1 inch

b. 2 inches

c. ¾ inch

d. ½ inch

3. Where a transformer is dedicated to supplying a fire pump installation, it shall be rated at

a minimum of what percent of the sum of the rated full load of the fire pump motor, plus

what percent of associated accessory equipment?

a. 125% -- 100%

b. 150% -- 175%

c. 175% -- 200%

d. 250% -- 300%

4. The primary overcurrent protective device(s) shall be selected or set to carry the sum of

the locked-rotor current of the fire pump motor(s) for which of the following time periods?

a. 1 hour

b. 2 hours

c. 3 hours

d. Indefinitely


5. All electric motor-driven fire pump control wiring shall be in one of the following?

a. Rigid non-metallic conduit

b. Rigid metal conduit

c. Type AC cable

d. Type MC cable


FIRE PUMPS

ARTICLE 695

LEVEL II

ANSWER KEY

1. d, Both A and B 695.3(A)(1) and (2)

2. a, 1” 695.4(B)(3)(c)

3. a, 125% -- 100% 695.5(A)

4. d, indefinitely 695.5(B)

5. b, Rigid metal conduit 695.14(E)


EMERGENCY SYSTEMS

ARTICLE 700

Level II

OBJECTIVE:

After completing this lesson each student should know what an emergency system is and the

special requirements that are applied when using emergency systems.

INTRODUCTION:

This article applies to the safety of the design, installation, operation, and maintenance of

emergency systems. This also applies to the wiring methods used to supply the required

equipment.

Emergency systems are those legally required by municipal, state, federal, or other codes and

classed as emergency. These systems automatically supply power/or illumination in case of

normal power failure.

(See FPN's under Article 700.1 for further information.)


Except as modified in this article all other articles shall apply. All equipment used on

emergency systems shall be approved for that use.

After installation of the emergency systems, the authority having jurisdiction shall require a

test of the system and periodic maintenance thereafter. A written record shall be kept of these

tests.

The capacity of the emergency system shall be adequate to supply all loads to be operated

simultaneously. Alternate power sources shall be permitted to supply legally required and

optional stand-by systems where automatic selective load pick-up and load shedding is

provided as needed to assure adequate power to (1) emergency circuits (2) legally required

standby circuits and (3) optional stand-by circuits, in that order of priority.

Transfer equipment shall be automatic and designed to prevent back feed to normal power

sources and identified for emergency use.

Explain- Audible and visual signal devices shall be provided, where practicable for the

detection of four problem conditions. Explain the four conditions (700.6) and why they need

to be detected. Explain that more detailed information can be found in NFPA 110.1996.

A sign shall be placed at the service equipment indicating type and location of on-site

emergency power sources.


All boxes and enclosures for emergency circuits shall be marked as a part of the emergency

systems. In general, all wiring from emergency systems shall be kept separate from all other

wiring and equipment. [See 700.10].

When normal power has been lost the emergency system is required to restore power within 10

seconds. When selecting a source of emergency power take into consideration the occupancy

and type of service to be rendered. Consideration shall also be given to the location and/or

design of equipment to minimize hazards that might cause failure due to floods, fires, icing,

and vandalism.

Storage batteries can be used but must maintain 87 1/2% of normal voltage for 1 1/2 hours.

Generator sets can be used with the following requirements:

1. 15 minute setting to prevent retransfer to normal power

2. Minimum of 2 hour fuel supply

3. Cannot depend solely on public utilities gas or water systems

4. Storage batteries used to start the generator must be approved for purpose and have

automatic charging means.

5. If more than a 10 second time delay must have auxiliary power source to pick up until

generator can take over.

6. The complete set must be acceptable to the authority having jurisdiction.

A separate service complying to Article 230 can be accepted if approved by the authority

having jurisdiction. The service drop or lateral shall be widely separated from the normal

source of power.

Go over requirements in Article 700.12 (F) for unit equipment. Point out it must be fixed in

place and if cord connected must have cord not over 3', must be fed from branch circuit on

normal lighting and fed of any local switch(s). In an uninterrupted area supplied by a

minimum of 3 lighting circuits a separate branch circuit shall be permitted from the same panel

as the normal lighting circuits.

No appliances, lamps or other than those specified as required for emergency use shall be

supplied by emergency lighting circuits.

Emergency Illumination shall be for egress lighting, (700.16) exit signs, and other lights as

necessary. Lights shall be designed so that when a bulb burns out the area will not be left in

total darkness. When high-intensity discharge lighting is used for normal lighting, emergency

lighting must operate until normal illumination has been restored.

Branch circuits supplying emergency lighting must be supplied from a source complying with

700.12 when normal supply is interrupted.

Switches installed on emergency circuits shall be accessible only to authorized persons (see

exceptions). Manual switches shall be located convenient to authorized persons responsible for

their actuation. In places of assembly, a control switch shall be in the lobby or convenient


thereto, but never in a projection booth, stage or platform. Branch circuit overcurrent devices

shall be accessible to qualified persons only.

APPLICATION:



It time will allow, correct the worksheets and discuss the results.


EMERGENCY SYSTEMS

ARTICLE 700

Level II

WORKSHEET

1. The sensor for ground-fault signal devices shall have a maximum ground fault current

setting of which of the following in amperes?

a. 600 amperes

b. 800 amperes

c. 1000 amperes

d. 1200 amperes

2. A location in which emergency circuits can be located in same enclosures as normal

circuits is which of the following?

a. transfer equipment

b. service equipment

c. receptacle outlets

d. all the above

3. When normal power fails emergency power must pick up within which of the following?

a. 60 seconds

b. 30 seconds

c. 20 seconds

d. 10 seconds

4. Storage batteries must carry full load for a period of not less than which of the following?

a. 30 minutes

b. 1 hour

c. 1 1/2 hour

d. 2 hour

5. A generator set is required to have a time delay of not less than which of the following to

prevent retransfer to normal power?

a. 10 minutes

b. 15 minutes

c. 20 minutes

d. 30 minutes


6. A generator is required to have on site fuel supply sufficient for not less than which of the

following for full-demand operation?

a. 1/2 hour

b. 1 hour

c. 1 1/2 hour

d. 2 hour

7. Flexible cord shall be permitted on unit equipment not in excess of which of the

following feet in length?

a. 2 feet

b. 3 feet

c. 4 feet

d. 6 feet

8. Where permitted a separate branch circuit for unit equipment can be fed from?

a. main service panel

b. any panelboard with a lock on feature

c. same panelboard as the normal lighting circuits

d. all of the above

9. All manual switches for controlling emergency circuits shall be in locations convenient to

authorized persons responsible for their actuation. In facilities covered by Articles 518 and

520, a switch for controlling emergency lighting systems shall be:

I- located in the lobby or at a place conveniently accessible thereto.

II- placed in a motion-picture projection booth or on a stage or platform.

a. I only

b. II only

c. both I & II

d. neither I nor II

10. Legally required emergency circuits may be installed with legally required circuits in these

enclosures:

a. Panelboards

b. Individual disconnect enclosure

c. Same vertical switchboard section

d. None of the above


EMERGENCY SYSTEMS

ARTICLE 700

Level II

ANSWER KEY

1. d, 1,200 700.5(D)

2. a, transfer equipment 700.10(D)(2)

3. d, 10 seconds 700.12

4. c, 1 1/2 hour 700.12(A)

5. b, 15 minutes 700.12 (B)(1)

6. d, 2 hours 700.12(B)(2)

7. b, 3 700.12(F)

8. c, same panelboard as the normal lighting circuits 700.12(F)

Exc. 1

9. (a) I only 700.21

10. d, 700.9(B)(5)(c)


LEGALLY REQUIRED STANDBY SYSTEMS

ARTICLE 701

Level II

OBJECTIVES:

After completing this lesson, each student should know: (1) what Legally Required Standby

Systems are and how they differ from emergency systems. (2) the wiring methods and

equipment included in Legally Required Standby Systems.

INTRODUCTION:

This article is designed to apply to electrical safety of the design, installation, operation, and

maintenance of the circuits and equipment designed to supply power and illumination when

normal power is interrupted. These systems, like emergency systems, are classed by

municipal, state, federal, or other codes or governmental agencies having jurisdiction. They do

not include those listed under emergency systems. (See FPN for list of examples)


All equipment used in Legally Required Standby Systems must be approved for the intended

purpose.

The authority having jurisdiction shall see that a test is performed upon completion and

periodically thereafter. Batteries used for starting or ignition of prime movers shall have

periodic maintenance. All these test shall be kept as a permanent record. Means shall be

provided for testing under load.

The system shall be of adequate size to supply the full capacity of all equipment intended to be

used at one time. When automatic selective load pick up and load shedding is provided as an

alternate power source shall be permitted to supply legally required standby systems.

Transfer equipment shall be automatic and identified for standby use or approved by the

authority having jurisdiction. Transfer equipment must be designed to prevent back feed to the

normal power source.

Explain that both audible and visual signals are required (where practicable) for the detection

of three problem conditions. Explain the three conditions (701.5) and why they need to be

detected. More detailed information is available in NFPA 110.

A sign shall be placed at the service entrance to indicate type and location of legally required

standby systems.

Unlike emergency systems legally required standby systems can occupy the same raceway,

junction box, cabinet, etc. as general wiring.


Sources of power shall be capable of restoring power within 60 seconds of loss of normal

power. In selecting a legally required standby source of power consideration shall be given as

to type of service and length of time of service and to equipment design to minimize the hazard

that might cause failure due to flood, fires, icing, and vandalism.

Storage batteries shall be capable of maintaining not less than 87 1/2% of system voltage for

not less than 1 1/2 hours. Automatic chargers shall be used and be compatible with batteries

used.

In using a generator set four things need to be followed (1) must have a 15 minute time delay

feature to prevent retransfer for at least 15 minutes (2) internal combustion engines shall have

on-site fuel supply to carry full load for at least 2 hours (3) Prime movers shall not depend

solely on public utility gas for fuel supply or municipal water for cooling. Where two fuel

supplies are used means shall be provided to switch from one to another. (4) Batteries shall be

provided with automatic chargers.

Where the authority having jurisdiction approves, a second service may be allowed as long as

there is a separate service drop or lateral and is widely separated.

Where acceptable to the authority having jurisdiction connection ahead of the main, not in the

main, shall be approved if sufficiently separated from the normal service.

Unit equipment shall consist of (1) rechargeable batteries (2) battery charging means (3)

provisions for one or more lamps and provisions for remote lamps (4) relaying device to

energize lamps upon failure of normal supply.

Branch circuit overcurrent devices shall be accessible to authorized persons only.

APPLICATION:






ARTICLE 701

Level II

WORKSHEET

1. Legally required standby power is required to be available within which of the following

from loss of power?

a. 10 seconds

b. 30 seconds

c. 60 seconds

d. 75 seconds

2. A sign shall be placed at the service entrance indicating which of the following

information regarding legally required standby power sources?

a. The size and kind.

b. The location of the transfer switch.

c. Type and location

d. All of the above.

3. Which of the following in legally required standby systems shall be accessible to

authorized persons only?

a. Power panels.

b. Branch circuit overcurrent devices.

c. Start/Stop Switches.

d. Transfer switch keys.

4. Which of the following is not an acceptable power source for required stand by systems?

a. generator set with 1 ½ hour fuel supply

b. storage battery with 1 ½ hour capacity

c. unit equipment with 1 ½ hour capacity

d. connection ahead of service disconnect

5. The legally required standby system wiring shall be permitted to occupy which of the

following

with general wiring?

a. the same raceways

b. the same cabinets

c. the same boxes

d. all of the above



ARTICLE 701

Level II

ANSWER KEY

1. c, 60 seconds 701.12

2. c, type and location 701.7(A)

3. b, branch circuit overcurrent devices 701.25

4. a, generator set with 1 ½ hour fuel supply 701.12(A)



OPTIONAL STANDBY SYSTEMS

ARTICLE 702

Level II

OBJECTIVE:

After completing this lesson, each student should know what an optional standby system is and

the wiring and equipment necessary to provide a safe installation.

INTRODUCTION:

Optional standby systems are intended for private business or property where life safety does

not depend on this system. (See FPN)


As in emergency and legally required standby systems all equipment shall be approved for use.

The system shall be sufficient for the capacity of all the equipment to be used at one time.

Transfer equipment shall be approved for use and designed to prevent back feed to normal

power.

Audible and visual signals, where practical, shall be installed to indicate derangement and that

the system is carrying a load.

Signs shall be installed at the service equipment indicating the type and location of optional

standby system.

System wiring shall be permitted to occupy raceways, boxes and cabinets with general wiring.

APPLICATION:






ARTICLE 702

Level II

WORKSHEET

1. Optional standby systems are those systems intended to supply power to public or private

facilities or property where life safety _______ depend on the performance of the system.

a. does

b. does not

c. doesn’t matter

d. can not

2. The optional standby system wiring shall be permitted to occupy the same _______ with

other general wiring.

a. raceways cables

b. boxes

c. cabinets

d. all of the above

3. A sign shall be placed at ______________________________________ indicating the

type and location of on-site optional stand-by equipment.

a. fuel tank

b. service-entrance equipment

c. maintenance shop

d. transfer switch

4. For what 2 purposes shall audible signals be required on optional standby equipment?

I- to warn when the fuel is low

II- To indicate that the optional standby source is carrying load.

a. I only

b. II only

c. both I & II

d. neither I nor II



ARTICLE 702

Level II

ANSWER KEY

1. (b) does not 702.2

2. (d) all of the above 702.9

3. (b) service-entrance equipment 702.8(A)

4. (b) II only 702.7(2)


CRITICAL OPERATIONS POWER SYSTEMS

ARTICLE 708

Level II

OBJECTIVE:

Each student should be familiar with and understand the nature of Article 708 as it relates to

systems necessary for emergency operations of governmental systems.

INTRODUCTION:

Explain the background and reasoning behind instituting guidelines and requirements for

maintaining certain public electrical and utility systems during extreme conditions caused by

loss of services due to weather related or human caused events.


Discuss different aspects and concerns based on the Authority Having Jurisdiction and who

that may be to take control and maintain order during catastrophic events where loss of power

and other systems lead to extreme environmental conditions for the inhabitants of the affected

community.

Explain the comparisons between emergency systems covered in Article 700 and how those

requirements there are necessary in addressing similar conditions under Article 708.

Relate the needs for planning by emergency management and proper governmental agencies

responsible for enduring the event and the recovery afterwards to move toward normal

conditions. Express the needs and concerns to understand Article 708

APPLICATION:

Allow the class time to complete worksheet.


Correct the worksheets and discuss the answers with the class.


ARTICLE 708

WORKSHEET

LEVEL II

1. Critical Power Operations Systems are those systems classed by:

a. Municipal agency

b. State agency

c. Federal agency

d. Any of the above

2. A Commissioning Plan shall be:

a. developed and documented

b. planned and approved

c. commissioned by the governing agency

d. made up of AHJ’s

3. Hazards to be considered at a minimum shall include:

a. Human caused events

b. Naturally occurring hazards

c. Only a.

d. Both a. & b.

4. Physical security shall be provided based on:

a. Risk assessment

b. Restricted access

c. Only risk assessment

d. Both risk assessment and restricted access

5. Overcurrent devices shall be accessible to:

a. qualified persons

b. only government officials

c. only military personnel

d. authorized persons

6. Alternate power sources shall be capable of operating the COPS for a minimum of:

a. 24 hours

b. 48 hours

c. 72 hours

d. 96 hours


ARTICLE 708

LEVEL II

ANSWER KEY

1. d. Any of the above 708.1

2. a. 708.8(A)

3. d. 708.4(B)

4. d. 708.5

5. d. 708.50

6. c. 708.22(C)


CIRCUITS AND EQUIPMENT OPERATING AT LESS THAN 50 VOLTS

ARTICLE 720

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with installations operating at less

than 50 volts direct or alternating current.

INTRODUCTION:

This article covers installations operating at less than 50 volts, DC or AC.


Cover installations requirements with emphasis on other sections that cover hazardous

locations, overcurrent protection, batteries and grounding. (720.3 & 720.9)

APPLICATION:






ARTICLE 720

Level II

WORKSHEET

1. Conductors for appliance branch circuits supplying more than one appliance or appliance

receptacle shall not be smaller than which of the following?

a. No. 8 aluminum or equivalent

b. No. 8 copper or equivalent

c. No. 10 copper or equivalent

d. No. 12 copper or equivalent

2. Standard Lampholders operating at less than 50 volts shall have a rating of not less than

which of the following watts?

a. 100 watts

b. 200 watts

c. 300 watts

d. 660 watts

3. Receptacles for equipment operating at less than 50 volts shall have a rating of not less

than which of the following?

a. 15 amperes.

b. 20 amperes

c. 12 amperes

d. 6 amperes

4. Receptacles of not less than the following rating shall be provided in kitchens, laundries,

and other locations where portable appliances are likely to be used?

a. 15 ampere

b. 20 ampere

c. 30 ampere

d. 40 ampere



ARTICLE 720

Level II

ANSWER KEY

1. c, No. 10 copper or equivalent 720.4

2. d, 660 720.5

3. a, 15 720.6

4. b, 20 ampere 720.7


CLASS I, CLASS II, and CLASS III REMOTE CONTROL,

SIGNALING AND POWER LIMITED CIRCUITS

ARTICLE 725

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the classification of remote

control, signaling and power limited circuits and the requirements for these circuits.


The definition for remote control, signaling and power limited circuits.

Cover the definition of PLTC cable (Power-Limited Tray Cable) 725.2 (new for 2014)

Class 1 remote control and signaling circuits shall not exceed 600 volts, however power output

of the circuit is not required to be limited.

725.3 Locations and other Articles are 300.17, 300.21, 300.22, 500 through 516, and 517, part

IV, Article 392 where installed in cable trays and 430 Part VI and.

Note: 2 new conditions Installation of conductors with other systems and Corrosive, Damp and

Wet Locations

Cover the applicable sections for this new requirement in articles 110.11, 300.5(b), 300.6,

300.9, and 310.10(g)

Wiring methods both supply and load side.

Ampacity per-section 310.15.

Insulation types as listed in 725.49(B). Insulation of conductors larger than 600 volts shall

comply to Article 310.

Number of conductors in cables and raceways.

Section 725.43 gives the requirements for overcurrent protection. Conductors #14 and larger

are to be protected in accordance with Table 310.15. It should be noted because of the

characteristics of these circuits no derating is required. Overcurrent protection shall not exceed

7 amperes for #18 and 10 amperes for #16.

Conductors of Different circuit [725.48] [725.133]


Different Class 1 circuits may occupy same enclosure, raceway cable etc. if all conductors are

insulated for the maximum voltage of any conductor present. Power supply and Class 1

conductors shall be permitted in the same enclosure only where functionally associated (see

exceptions).

Conductor [725.49]

A. Ampacities per tables 402.5 and 310.16 through 310.21 as applicable.

B. Insulation types (must be suitable for the system voltage and not less than 600 volts),

review insulation types for #18 and #16 size conductors

Physical protection [725.31(B)]

Where subject to damage conductors must be in conduit or otherwise suitably protected.

C: Class 2 and Class 3 circuits

Power Limitations of Class 2 and Class 3 circuits [725.121]

Power for Class 2 or Class 3 shall be either inherently limited requiring no overcurrent

protection or limited by a combination of power source and overcurrent protection.

APPLICATION:







ARTICLE 725

Level II

WORKSHEET

1. What is the maximum voltage for a Class 1 power limited circuit?

a. 30 volts

b. 50 volts

c. 75 volts

d. 120 volts

2. What is the maximum power output for Class 1 power limited circuit?

a. 300 VA

b. 600 VA

c. 1000 VA

d. 1200 VA

3. The maximum voltage for a Class 1 remote control circuit is:

a. 120 Volts

b. 250 Volts

c. 300 Volts

d. 600 Volts

4. A Class 2 or 3 power supply shall be which of the following to indicate the class of

supply and electrical rating.

a. A listed Class 2 or Class 3 transformer

b. A listed Class 2 or Class 3 power supply

c. listed equipment marked to identify the Class 2 or 3 power source

d. all of the above

5. For other applications, conductors of Class 2 and Class 3 circuits shall be separated by at

least what distance from conductors of any electric light, power, Class 1 non–power-

limited fire alarm or medium power network-powered broadband communications circuits

unless one of the following conditions is met:

a. 2 in.

b. 6 in

c. 12 in.

d. none of the above




ARTICLE 725

Level II

ANSWER KEY

1. a, 30 volts 725.41(A)

2. c, 1000 725.41(A)

3. d, 600 725.41(B)


5. a, 2 inches 725.136(I)


INSTRUMENTATION TRAY CABLE

ARTICLE 727

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with how type ITC cable may be

used.

MATERIALS NEEDED:

Sample of type ITC cable showing markings on sheath.


1) Cover the uses permitted in section 727.4 and uses not permitted in section 727.5

2) Cover construction, sizes, and ampacities of ITC.

APPLICATION:






ARTICLE 727

Level II

WORKSHEET

1. The insulated conductors of type ITC Cable shall be in sizes:

a. No. 14 through 16

b. No. 8 through 10

c. No. 22 through 12

d. No. 2 through 6

2. The ampacity of the conductors of instrumentation tray cable shall be:

a. 5 amperes except 22 AWG shall be 3 amperes

b. 10 amperes except 22 AWG shall be 5 amperes

c. 15 amperes except 22 AWG shall be 8 amperes

d. 9 amperes except 22 AWG shall be 6 amperes



ARTICLE 727

Level II

ANSWER KEY

1. c, No. 22 through 12 727.6

2. a, 5 amperes except 22 AWG shall be 3 amperes 727.8


FIRE PROTECTIVE SIGNALING SYSTEMS

ARTICLE 760

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the installation of wiring

systems and equipment of fire protective signaling systems operating at 600 volts, nominal, or

less.

INTRODUCTION:

Fire protective systems are one of the most important components of an electrical system.

Because of the danger to life and property and the liability involved, it is essential that the

system work as expected.


Article 760 of the NEC addresses the requirements and wiring methods to be used when

installing fire protective systems. Other articles which apply include: 300.21, 300.22, 500-

through 516 for and 517 Part IV. The building code also determines system requirements so

coordination with building inspection department is necessary.

Fire Protective circuits are classified as either non-power limited or power limited [760.2]. All

circuits must comply with Part A. Parts B and C apply to non-power limited and power limited

circuits respectively.

Part B-Nonpower limited FPSC: Discuss thoroughly.

Conductors of Class 1 and NPLFA circuits that occupy the same raceway must be insulated for

the maximum voltage present. See 760.48(A)

Conductors shall be solid or stranded copper and comply with provisions of 760.49(C).

Multiconductor cable must be listed for fire alarm use. The number of conductors in raceway is

determined by 760.51.

Part III-Power-Limited (PLFA) Circuits: Circuits must be clearly marked at terminations as a

power limited fire alarm circuit.

Wiring on supply side of overcurrent protection, transformers etc. must be installed in

accordance with Part II of 760 and Chapter 3 wiring methods.

Power limited circuit conductors must be installed according to 760.133. Signaling circuits

installed as wiring within buildings must be listed for resistance to fire spread. Cover 760.133.


Power limited circuits must meet the requirements of 760.136 for separation from light, power,

Class 1 and non-power limited fire protective circuits. Go over exceptions. (760.130)

Cover conditions under which Class 2 circuits can be permitted within same raceway with

power limited fire protective signaling circuits. (760.139)

Conductors and cables must be listed for fire protective system use and meet or exceed the

requirements of 760.53. Listed cable must be marked to comply with 760.161 and 760.176G.

Show overhead of Table 760.176(G).

APPLICATION:






ARTICLE 760

Level II

WORKSHEET

1. Fire alarm circuits shall be identified at which of the following locations in a manner that

will prevent unintentional interference with the signaling circuit during testing and servicing?

a. Terminal and junction locations.

b. Pull stations and terminal junctions.

c. Terminals and cardholders.

d. Cardholders and Pull stations.

2. When extending beyond one building power-limited fire alarm circuits shall meet

installation requirements of which of the following?

I. Parts II, III, and IV of Article 800

II. Part I of Article 300

a. I only

b. II only

c. Neither I or II

d. Both I and II

3. Overcurrent protection shall not exceed which of the following for #18 conductors?

a. 10 amperes

b. 7 amperes

c. 6 amperes

d. 5 amperes

4. NPLFA conductor materials shall be of which of the following?

I. Solid copper.

II. Stranded copper.

a. I only

b. II only

c. Neither I or II

d. Either I or II


5. Where located within 7 feet of the floor, NPLFA cable shall be securely fastened at

which of the following intervals?

a. 1 ½ feet

b. 2 feet

c. 4 feet

d. 3 ft. 6 inches

6. Type FPL cables installed as wiring within buildings shall be listed as which of the

following?

I. Listed as being resistant to the spread of fire.

II. Listed for circuit integrity and marked with the suffix CI

a. I only

b. II only

c. Neither I nor II

d. Both I and II

7. Which of the following types of power limited fire alarm plenum cable shall be listed for

use in ducts or plenums and other air-handling spaces?

a. BFPLP

b. FPLP

c. PLPF

d. PPLF

8. Power-limited circuits shall be separated from Class I circuits by which of the following

distances?

a. 12 inches

b. 6 inches

c. 4 inches

d. 2 inches



ARTICLE 760

Level II

ANSWER KEY

1. a, terminal and junction locations 760.30

2. d, Parts II, III, and IV of Article 800 and Part I Article 300 760.32

3. b, 7 amp 760.43

4. d, either I or II 760.49 (C)

5. a, 1 ½ feet 760.53(A)(1)

6. a, I only 760.179(F)

7. b, FPLP 760.179(D)

8. d, 2 inches 760.136(G)


OPTICAL FIBER CABLES AND RACEWAYS

ARTICLE 770

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with optical fiber cables and it’s

permitted use and types.

MATERIALS NEEDED:

Samples or pictures of cable.

INTRODUCTION:

Explain to student that this is a short article, and it will be covered very briefly. It is not very

often encountered in the field at the present time but this will be more common in the future.


Show samples or pictures of cables. Cover types of optical fiber cables [770.5] and other

articles that apply to their installation. [770.3]

Emphasize the requirement for wiring within building and the fire resistant rating of cables and

cable marking. [770 Part III]

Cover the requirement of installing optical fiber and electrical conductors in the same raceway.

[770.6]

Discuss mechanical execution of work. [770.8]

APPLICATION:





OPTICAL FIBER CABLES

ARTICLE 770

Level II

WORKSHEET

1. Which of the following is correct concerning the installation of conductive optical fiber

cables?

I. Optical fibers shall be permitted in the same raceway with class 2 and class 3 remote

control signaling and power-limited circuits.

II. Nonconductive optical fiber cables shall not occupy the same outlet box housing as the

class 1 circuit. (without exception)

a. I only

b. II only

c. Both I and II

d. Neither I nor II

2. Optical fiber cables installed as wiring for general use within buildings shall be which of

the following?

I. Shall be OFC type.

II. Shall be OFN type.

a. I only

b. II only

c. Both I and II

d. Neither I nor II


OPTICAL FIBER CABLES

ARTICLE 770

Level II

ANSWER KEY

1. c, Both I and II 770.133(A) and (B)

2. c, Both I and II 770.179(D)


COMMUNICATION CIRCUITS

ARTICLE 800

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar with the requirement for

communication circuits.

INTRODUCTION:

This Article covers the requirement for telephone, telegraph, district messenger, outside wiring

for fire alarm and burglar alarms.


Part II covers the requirement for outside conductors. Go over 800.44 as to the requirement for

overhead conductors -- on poles, on buildings, and entering buildings.

Part II also covers Underground Circuits entering buildings. Cover the requirements,

800.47(A), for separation of communication circuit from light and power conductor in

handholes, manholes, etc.

Part III covers the requirements for protective devices. Emphasis should be placed on the type

and location of the protector as covered in 800.90.

Part IV covers Grounding of communication circuits. Special emphasis should be placed on.

This covers the cable sheath and protection ground with requirement for insulation, size and

installations of the grounding conductor. Emphasis should be placed on the electrode and

electrode connection.

Part V places special emphasis on the installation of conductors is necessary to make sure the

student is familiar with these requirements. Cover the requirements concerning the separations

from other conductors. The requirement for fire resistance of wires and cables installed as

wiring within buildings should be emphasized. (OL Table 800.113) Note the requirement for

listing of the conductors.

APPLICATION:






ARTICLE 800

Level II

WORKSHEET

1. The primary protector shall be located in which of the following places?

I. On, or immediately adjacent to the structure or building served.

II. As close as practicable to the point of entrance.

a. I only

b. II only

c. Neither I or II

d. Both I and II

2. Communication conductors run in the same shaft with light and power conductors shall

be separated by which of the following?

a. 2 inches

b. 6 inches

c. 2 feet

d. 30 inches

3. Communication cables installed in plenums shall be listed and marked in which of the

following manners?

a. CM

b. CMP

c. CMR

d. CMX

4. The communication grounding electrode conductor shall be which of the following?

I Insulated (Covered or Bare)

II. Listed

a. I only

b. II only

c. Neither I nor II

d. Both I and II



ARTICLE 800

Level II

ANSWER KEY

1. d, Both I and II 800.90(B)

2. a, 2 inches 800.133(A)(2)

3. b, CMP 800.154(A)

4. d, both I and II 800.100(A)(1)


RADIO AND TELEVISION EQUIPMENT

ARTICLE 810

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar the requirements of radio and

television receiving equipment and amateur transmitting and receiving equipment.

MATERIALS NEEDED:

Slides or transparencies of connections of grounding conductor to electrode.

INTRODUCTION:

This Article covers the requirement of antenna systems for radio and TV receiving equipment,

amateur transmitting and receiving antenna system and interior transmitter station installations.


Refer to the other Articles that pertain to the general wiring methods for power to these

systems. Sound recording (640) and optical fiber cables (770) shall comply with their

applicable Articles. The distribution system for CATV is not covered in Article 810 but

covered in Article 820.

810-Part II (810.11 through 810.21) This part covers antenna systems for receiving equipment.

Areas that should be emphasized are materials, supports, proximity of conductor to other

system, and splicing. Other areas of emphasis should be size of lead-in conductor and

clearances on the outside and inside of buildings.

Special emphasis should be given to section 810.15 and 810.20 and 810.21. These sections

cover the requirements for grounding masts and metal structures supporting antennas and

antenna discharge units.

Section 810.21 covers the requirements for grounding conductors. Be sure to go over the

requirements covered in Sections 810.21 (F)(1)(2)(3), 810.21(G)(H)(I)(J) & (K) as it relates to

the overall grounding requirements for radio and television equipment.

APPLICATION:






ARTICLE 810

Level II

WORKSHEET

1. This article covers antenna systems for radio and television receiving equipment, amateur

and citizen band radio transmitting and receiving equipment, and certain features of transmitter

safety. This article also covers all of the following except?

a. Antennas such as multi-element.

b. Vertical rod, and dish antenna.

c. The wiring and cabling that connects them to equipment.

d. Antennas used for coupling carrier current to power electronics

2. What is the maximum distance between supports for medium or soft drawn copper when

used with antenna systems?

a. Less than 50 feet

b. Less than 25 feet

c. Less than 35 feet

d. Less than 10 feet

3. Outdoor antenna and lead-in conductors when in proximity of power conductors of less

than 250 volts between conductors shall maintain a clearance of which of the following?

a. 2 inches

b. 2 feet

c. 6 inches

d. 6 feet

4. What size hard drawn copper would be required for a one hundred (100') foot span for

Receiving Station outdoor antenna conductors?

a. 12

b. 14

c. 19

d. 20

5. The minimum size grounding conductor shall not be smaller than which of the following?

a. 10 copper

b. 8 copper

c. 17 copper

d. 6 copper



ARTICLE 810

Level II

ANSWER KEY

1. d, antennas used for coupling carrier current 810.1

2. c, less than 35 feet 810.11 ex.

3. b, 2 feet 810.13

4. b, 14 Table 810.16 (A)

5. a, 10 810.21(H)


COMMUNITY ANTENNA TELEVISION AND

RADIO DISTRIBUTION SYSTEMS

ARTICLE 820

Level II

OBJECTIVE:

After completing this lesson, each student should be familiar the requirements for radio and

CATV distribution systems.

MATERIALS NEEDED:

Samples of listed cables.

Slides or transparencies of connection of grounding conductor to electrode.

INTRODUCTION:

This Article covers the requirement for protection, installation and grounding of cables for

CATV and radio distribution systems.


This Article covers the cable distribution system for CATV and Radio. Part I covers the

energy limitation, material, and requirement for marking the cable. Emphasis should be placed

on the requirement for listing and special marking on the cable as required in Section 820.179

and Table 820.179.

Part II covers the requirements for lighting and power surge protection for cable entering the

building. Emphasis should be placed on the proper application of protective devices.

Part III covers the protection of cables. Cover 820.44 , outside conductor, with emphasis on

(F) (1), (2) and (3) covering separations of cables from conductor of other systems. Cover

Section 820.133, inside conductors, with emphasis on part (A) -- separation of cables and light

and power conductors; installations of cable in raceway, boxes etc.; and installation of cable

with other conductor when installed in accordance with their respective Article.

Special emphasis should be placed on Section 820.3(A). These sections cover requirements for

the prevention of spread of fire and products of combustion. Note the requirements for fire

rating of coaxial cable installed within building, vertical shafts and ducts, plenums and other

air handling spaces.


Part IV covers the requirement for grounding the coaxial cables. Special emphasis should be

placed on Section 820.100. This covers grounding requirement-material, size etc. and the

requirement for electrode and electrode connection.

APPLICATION:







ARTICLE 820

Level II

WORKSHEET

1. Coaxial Cable shall be permitted to deliver low-energy power to equipment associated

with the radio frequency distribution system if the voltage is not over which of the following?

a. 60 volts

b. 100 volts

c. 120 volts

d. 250 volts

2. Listed CATV cables used in a plenum shall be marked as which of the following?

a. CATV

b. CATVD

c. CATVP

d. CATVR

3. CATV and lightning conductors should be spaced at least what distance apart?

a. 2 feet

b. 4 feet

c. 6 feet

d. 10 feet

4. The minimum size grounding conductor shall not be smaller than which of the following

for CATV systems?

a. 16

b. 14

c. 12

d. 6




ARTICLE 820

Level II

ANSWER KEY

1. a, 60 820.15

2. c, CATVP 820.154(A)

3. c, 6 feet 820.44(E)(3)

4. b, 14 820.100(A)(3)

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