Power Plus Training Services An introduction to our training programs

28064 Center Oaks Court, Wixom, MI 48393-3343 ¤ (248) 344-0200 / Fax (248) 305-9105

www.epowerplus.com email:[email protected]

Power Plus Training ServicesPower Plus Training ServicesAn introduction to our training programs



Power Plus Training ServicesPower Plus Training Services Specializing in

nationwide “hands-on” electrical testing and safety training

Delivered at your facility, eliminating employee travel expenses

Instructors are NETA certified test technicians and trained in the facilitation of the learning process

All courses designed to meet OSHA and NFPA 70E requirements



Power Plus Training ServicesPower Plus Training Services Courses available

– Industrial Electrical Safety

– NFPA 70E Electrical Safety

– Electrical Awareness for Emergency Responders

– Circuit Breaker Operation and Maintenance

– Transformer Operation and Maintenance

– Substation Safety and Operation

– Substation Maintenance

– NEC Training

– Electrical Theory

– Electrical Grounding Practices



Power Plus Training ServicesPower Plus Training Services Customized training

– All courses may be customized to you plants specific equipment and procedures

– Student learn by doing “hands-on” labs on the actual equipment they will be applying the skills learned

Customers include:

– General Motors

– BASF

– Ford Motor Company

– ABB

– DaimlerChrysler

– US Coast Guard



Electrical SafetyElectrical SafetyArc Flash Hazard Analysis



Flash Hazard AnalysisFlash Hazard Analysis

The NFPA 70E states, “A Flash Hazard Analysis shall be done in order to protect personnel from the possibility of being injured by an arc flash. The analysis shall determine the Flash Protection Boundary and the personal protective equipment that people within the Flash Protection Boundary shall use.”



Flash Hazard Analysis Flash Hazard Analysis The intensity level of an arc flash can be

calculated

A flash hazard analysis consists of 2 parts:

– Determining the flash hazard boundary

– Determining the incident energy level the worker would be exposed to

Boundary is based on the following:

– Amount of available fault current

– Distance of the electrode gap

– The clearing time of the protective device

Once the data is gathered, the flash protection boundary can be determined



Dcb= (MVA*53*t)Example: (3*53*.1Sec)=3.99 Ft

Flash Hazard AnalysisFlash Hazard Analysis For systems that are 600V or less, the Flash

Protection Boundary shall be 4 feet, based on the product of clearing times of 6 cycles and the available bolted fault current of 50,000A or any combination not exceeding 300kA cycles

For clearing times and bolted fault currents other than 300kA cycles, or under engineering supervision, the Flash Protection Boundary shall be alternatively be permitted to be calculated in accordance with the following general formula:



Flash Hazard AnalysisFlash Hazard Analysis Excel program

using NFPA 70E Equations

Download at www.epowerplus.com

Example:

– 3000kVA 480V transformer

– 6 cycle clearing time

DC=3.99 ft



Flash Hazard Analysis Flash Hazard Analysis

The flash protection boundary determines at what distance from exposed live parts flash protection must be worn

Distance is usually based on not exceeding 1.2 cal/cm2 of heat energy on a persons skin

1.2 cal/cm2 will cause a 2nd degree burn of exposed skin in 0.1 second



Flash Hazard AnalysisFlash Hazard AnalysisThe next step is

to determine the Incident Energy (EI) level that a worker would be exposed to if an arc flash were to occur.

The goal of this calculation is to determine the amount of heat energy a worker would be exposed to during an arc flash event



Flash Hazard AnalysisFlash Hazard Analysis Excel program

using NFPA 70E Equations

Download at www.epowerplus.com

Example:

– 36kA available

– EI at 18”




36kA will trip breaker in .07 seconds

Add breaker opening time (.06)

Arc duration would be about .13 sec

Given the following curve for a 1200A breaker



Flash Hazard AnalysisFlash Hazard Analysis A 36 kA fault

with a 0.13 second clearing time at 18”

EI will be:

– 6.408 Cal/cm2 in open air

– 10.6607 Cal/cm2 in a cubic box




13.68kA will trip breaker in .35 seconds

Add breaker opening time (.06)

Arc duration would be about .41 sec

At 38% IBF would be 13,680A (or 11.4x LT setting)



Flash Hazard AnalysisFlash Hazard Analysis At 36kA and

.13 sec

Open Air was 6.408 Cal/cm2

Cubic box was 10.6607 Cal/cm2

Which is worse?

A 13.8 kA fault with a 0.41 second clearing time at 18”

EI will be:

– 8.205 Cal/cm2 in open air

– 17.9508 Cal/cm2 in a cubic box



Flash Hazard AnalysisFlash Hazard Analysis The PPE necessary

to perform a task inside of the flash hazard boundary may be determined from the resultant Incident Energy from the flash hazard analysis.

The incident energy level determines the Hazard Risk Category (HRC) PPE rated for the available incident energy will prevent the onset of a second degree burn if an arc flash were to occur

Incident Energy Level

Hazard Risk Category

0-<4 cal/cm2 1

4-<8 cal/cm2 2

8-<25 cal/cm2 3

25-<40 cal/cm2 4

>40cal/cm2 Dangerous



Electrical SafetyElectrical SafetySelection and use of Personal Protective Equipment



Personal Protective EquipmentPersonal Protective Equipment



PPE Selection tablesPPE Selection tables

Task (Assumes equipment is energized, and work is done within the flash protection boundary)

Hazard/RiskCategory

V-RatedGloves

V-Rated Tools

Panel boards rated 240V and below - Notes 1 and 3 - - -

CB or fused switch operation with covers on 0 N N

CB or fused switch operation with covers off 0 N N

Work on energized parts, including voltage testing 1 Y Y

Remove/Install CB's or fused switches 1 Y Y

Removal of bolted covers (To expose bare, energized parts) 1 N N

Opening of hinged covers (To expose bare, energized parts) 0 N N

Find the task you will be performingFind the type of equipment you will be working on

Find the level of flash protection neededDetermine if gloves are neededDetermine if insulated tools are needed



PPE SelectionPPE Selection

Protective Clothing & Equipment

Protective System for Hazard / Risk Category

Hazard / Risk Category Number (-1) Note 3 0 1 2 3 4

Untreated Natural Fiber - - - - - -

T-shirt (short sleeve) X X X X

Shirt (long sleeve) X

Pants (long) X X X (Note 6)

X (Note 6) X X

Find your risk category

Determine the PPE needed



Typical Protective ClothingTypical Protective Clothing

Hazard Risk Category 0

– Untreated Cotton long sleeve shirt and pants

– Safety Glasses

– PPE cal/cm2 -- N/A



Typical Protective ClothingTypical Protective Clothing

Hazard Risk Category 1

– Long sleeve FR Shirt & Pants (Jeans are acceptable)

– Hard Hat

– Safety Glasses

PPE cal/cm2 -- ≥ 4.0



Typical Protective ClothingTypical Protective Clothing Hazard Risk Category 2

– Cotton T-shirt plus FR shirt & FR Pants

– Leather Gloves and Shoes

– Hard Hat

– Safety Glasses

– Hearing protection

– Arc rated face shield or double layered switching hood

– PPE cal/cm2 -- ≥ 8.0

– * = Must use a double layered switching hood and hearing protection in addition to level 2 requirements

+ Or



Typical Protective ClothingTypical Protective Clothing Hazard Risk Category 3

and 4– Cotton T-shirt and pants

– Leather Gloves and Shoes

– Hard Hat, Liner, Safety Glasses

– Double layered switching hood and hearing protection

– Multiple layers of FR clothing or switching suit to equal cal/cm2 requirements

PPE cal/cm2

– HRC 3 -- ≥ 25.0

– HRC 4 -- ≥ 40.0



Safety GlovesSafety Gloves Employees shall

wear rubber insulating gloves where there is a danger of arm and hand injury from electrical shock and burns due to contact with live parts

Gloves used shall be of the appropriate voltage class



Safety GlovesSafety Gloves Label on insulating equipment

contains the following information:

– Manufacturer

– ANSI/ASTM Reference

– Size (Gloves)

– Type

– Class



Glove selectionGlove selection Glove size is

important to ensure a proper fit and dexterity

Size is inches around the palm of your hand

Types:

– Type 1 – Non-Ozone resistant (Natural rubber)

– Type 2 – Ozone resistant (Synthetic)



Glove selectionGlove selectionMake sure you have the right glove for the

right job!

CLASSMAX USE VOLTAGE

A-C RETEST VOLTAGE

CLASS 00 500 2,500

CLASS 0 1,000 5,000

CLASS 1 7,500 10,000

CLASS 2 17,000 20,000

CLASS 3 26,500 30,000

CLASS 4 36,000 40,000



Glove TestingGlove Testing Gloves are required to

be lab tested every six months

The tests include:

– Dielectric test at voltage on previous chart

– Air test

– Cleaning

– Visual inspection

(Courtesy Reed City

Power Line)



Glove inspectionGlove inspection Gloves should be

inspected prior to each use

The inspection should include:Visual inspection checking for:

•Cracks

•Punctures

•Ozone damage

•Snags

•Embedded material

Air test



Protective EyewearProtective Eyewear ANSI Z87.1

– Impact protection

– UV Attenuation

Will not withstand heat generated from arc flash

Must be tested for thermal Protection per ASTM 1959!

http://www.aplussafety.net/products/index.cfm?d=3136&c=4602&p=17083&do=detail



Hard HatsHard Hats

Class Voltage Rating

Class (Prior to 1999)

G 2,200V A

E 20,000V B

C 0V C

Hard hats used for electrical shock protection must be rated

for the voltages present

Do not:– Drill holes for ventilation

– Paint

– Use excessive number of stickers (Check state OSHA regulation)



Foot ProtectionFoot Protection Electrical workers shall

wear rubber soled shoes but they may not be used as primary electrical protection

Leather work shoes are recommended for all tasks and shall be used for incident energy exposure levels 4 cal/cm2 and higher

Where insulated footwear is used as protection against step and touch potential, dielectric overshoes shall be required

These overshoes follow under the same testing requirements as gloves



Transformer Construction and Maintenance


Transformer Theory



Transformer TheoryTransformer Theory William Stanley invented the transformer

in 1886

His basic design is still the principle by which all transformers are designed today

When current is passed through a conductor a magnetic field is induced



Transformer TheoryTransformer Theory The direction of the field can be

determined by using the right hand rule for conductors

When an AC is passed through a conductor the field produced is constantly expanding and collapsing



Transformer TheoryTransformer Theory When another conductor is placed in this

changing magnetic field, a voltage will be induced in the conductor

If a complete circuit exists on the secondary, current will flow through the circuit as shown below



Transformer TheoryTransformer Theory A transformer can

be divided into three parts:

– Primary Windings

– Secondary Windings

– Core

The primary and secondary windings are linked by a common flux produced in the iron core



Fact or Fiction?Fact or Fiction?

Fiction!

It will still work, but will be less efficient

“A transformer will not work without a core ”



Power in the transformerPower in the transformer Transformers are

rated in volt-amps

EpIp = ESIS

What is the turns ratio?

If primary current was 25A, what would secondary current be?



Transformer LossesTransformer Losses Exciting current is the current needed to set

up the magnetic flux in the windings and core

The losses from the excitation current is called core loss, which is subdivided into two categories:

– Eddy Current Losses: Losses from small circulating currents in the core

– Hysteresis Losses: Caused by the energy required to align the domains in the magnetic core material

The magnetic flux in the core and the current flowing in the windings generate heat, which is called copper loss, and is equal to the square of the current times the resistance of the windings



Eddy current lossesEddy current losses Iron is a conductor of

electricity as well as being an excellent "conductor" of magnetic flux

There will be currents induced in the iron just as there are currents induced in the secondary windings from the alternating magnetic field

These induced currents tend to circulate through the cross-section of the core perpendicularly to the primary winding turns

The main strategy in mitigating these wasteful eddy currents in transformer cores is to form the iron core in sheets each sheet covered with an insulating varnish so that the core is divided up into thin slices

The result is very little width in the core for eddy currents to circulate in



Hysteresis lossHysteresis loss

A: Because it doesn't know the words!

Q: Why do transformers hum?



Hysteresis lossHysteresis loss

Here is a piece of ferromagnetic material showing each molecule as tiny magnetsWhen a magnetic field is applied they all line up

When the direction of the field reverses, they all flip around 180 degrees

This occurs 120 times per second (60Hz)

Each realignment causes a vibration

The vibration is heard as the familiar hum

A “B Flat” note is very close to 120 Hz



Hysteresis lossHysteresis loss All ferromagnetic

materials tend to retain some degree of magnetization on a molecular level after exposure to an external magnetic field

This tendency to stay magnetized is called "hysteresis"

Hysteresis losses can be mitigated by choosing a core alloy with low hysteresis, as evidenced by a "thin" B/H hysteresis curve



Effect of harmonicsEffect of harmonics Transformer energy losses tend

to worsen with increasing frequency

– The skin effect within winding conductors reduces the available cross-sectional area for electron flow, thereby increasing effective resistance as the frequency goes up

– Magnetic core losses are also exaggerated with higher frequencies, eddy currents and hysteresis effects becoming more severe

Modern power systems are exposed to high frequencies from harmonics produced by switching loads (I.E. VFD’s)

A K-Factor rated transformer is designed to handle these harmonics by utilizing a larger core





Transformer inspections



InspectionsInspections Voltage: Primary and

Secondary voltage should be maintained within set limits

Load Current: The loading will determine the heat generated in the transformer. The heating determines the life expectancy so monitoring load current is a simple method of predicting failures. Load monitoring should be done on an hourly basis or by the use of data recording equipment



InspectionsInspections Temperature: The maximum

allowable temperature is the ambient temperature plus the rated maximum temperature rise. A common thumb rule for life expectancy of transformers is as follows:– Class “A” insulation - 8C

above max temp rating= ½ life expectancy

– Class “B” insulation - 12C above max temp rating= ½ life expectancy

Liquid level: Level loss may occur from leaks or evaporation of the fluid. Any liquid losses should be replaced immediately



Inspections (Liquid Filled)Inspections (Liquid Filled)

External Inspection: This inspection includes checking the tank, radiators, auxiliary equipment, gaskets, and metal parts for corrosion and leaks



Inspections (Liquid Filled)Inspections (Liquid Filled) Auxiliary equipment:

Fans, oil pumps, and cooling fins should be checked for proper flow and operation. Worn or damaged parts should be repaired or replaced



Inspections (Dry Type)Inspections (Dry Type) Inspect fans for

proper operation by taking the mode selector switch to manual

Clean filters for proper air flow



InspectionsInspections Transformer liquid

Air, moisture, and heat are the most common contributors to the breakdown of the fluid

These contaminates react with the fluid and create sludge and acids, which in turn will damage the insulation

Samples should be taken on at least an annual basis and analyzed by an approved test lab that follows ASTM standards



InspectionsInspections More in-depth

inspections require the transformer to be shut down and placed in an electrically safe working condition

The following is a brief summary of the items to be inspected while the transformer is shut down



InspectionsInspections Protective devices:

The following devices should be inspected and tested on an annual basis

– Overcurrent phase and ground relays

– Differential relays

– Sudden pressure relays

– Under/Over voltage relays

– Alarms

– CT’s and associated wiring for relays



InspectionsInspections

Pressure relief device: Liquid filled transformers are equipped with pressure relief devices that are usually set to open at 10-15 psi

Inspections should include checking for leak around joints, diaphragm cracking, and gasket condition



AccessoriesAccessories Sudden pressure relays are designed to

respond to a rapid buildup of pressure in the 2 to 6 PSI range over the 0.02 to 6.0 second time band

Gas build-up can lead to possible explosions as seen here



InspectionsInspections

Ground Connections: The grounding straps should be inspected daily for damage and loose/corroded connections. The substation ground should be checked on an annual basis for proper continuity



InspectionsInspections Insulators:

Insulators should be inspected for tightness, dirt accumulation, water damage, and damaged surfaces

Lightning arrestors: Arrestors should be inspected for tightness, dirt accumulation, water damage, and damaged surfaces. Any dirt or deposits should be cleaned and all loose connections should be tightened



Inspections (Dry type)Inspections (Dry type) Any dirt present should

be removed to permit circulation of air and to aid in the prevention of insulation failure

Compressed air (<25 Psi) and a vacuum cleaner should be used to remove dirt from the windings

All leads, terminations, bushings, and other surfaces should be wiped clean with a dry, lint free cloth

Liquid cleaners should not be used because they may deteriorate the insulation



Inspections (Liquid filled)Inspections (Liquid filled) Internal inspection: this inspection

involves an internal investigation of the tank (liquid filled), windings, and core

This inspection is only done after the unit has been placed in an electrically safe working condition



Circuit Breaker Construction and Maintenance

Circuit Breaker Construction and Maintenance

A guide to proper maintenance of Low Voltage power circuit breakers



Circuit Breaker MaintenanceCircuit Breaker Maintenance Ensure the circuit

breaker is isolated from the power circuit

Always refer to the breaker's maintenance manual

In general, the three basic rules of electrical inspections apply to all circuit breakers:

– Keep it tight

– Keep it clean

– Keep it dry



Contact InspectionContact Inspection The first step for the contact

inspection is to remove the arc chutes

The arc chutes should be inspected for damage, missing pieces, and cleanliness

Low-pressure air can be used to clean out the arc chute assemblies

After the chutes are removed the circuit breakers main and arcing contacts should be visually inspected for alignment and wear



Contact InspectionContact Inspection Silver-plated contacts

normally require little maintenance but may be surface dressed to assure maximum contact at the mated surfaces. This should not be aggressive enough to remove the silver plating or change the shape of the contact surface

If contacts are pitted or eroded they must be reconditioned or replaced

Contact alignment may be checked visually by conducting a “Slow-close” procedure on the breaker



DisconnectsDisconnects Ensure that there are no

broken elements and the disconnects fit snugly together when joined

Disconnects should be lubricated to help them mate together smoothly when installing or removing the breaker from its cubicle

Excessive lubrication will attract dust and other contaminants, and eventually introduce further problems

Apply the lubricant generously then wipe off all the excess



Operating MechanismOperating Mechanism This inspection ensures

cleanliness, nuts, and bolts are tight, and there is no physical damage

The operating mechanism should be lubricated according to the breaker's maintenance manual to ensure it operates freely through its entire stroke

Avoid lubricant on the arc chutes and other electrical parts that may get hot during operation

The operating mechanisms should be cycled several times to make sure that they are working smoothly and are free from binding



Contact ResistanceContact Resistance One of the most

important test is the contact resistance measurement across the breakers closed contacts

High contact resistance will cause overheating and eventual failures



Contact ResistanceContact Resistance Low resistance bridges

provide indication of the contact resistance in microhms

The test set should have at least a 10A output for accurate readings

A LVCB should be less than 100 micro-ohms

Values should never exceed 1.5 times the value of a new breaker or 1.5 times the lowest reading of one pole



Insulation Resistance TestsInsulation Resistance Tests Insulation resistance

(IR) tests are commonly performed with a megohmmeter

Test results should only be interpreted for comparative purposes

Does not indicate the quality of the primary insulation system from the point of view of dielectric strength



Custom TrainingCustom TrainingCustomized training on your plants equipment



Utility feeds to Plant “X”Utility feeds to Plant “X”

The Utillity provides two 120 kV lines to the facility

These lines enter the outdoor switchyard on the east side of the plant near the powerhouse



Plant “X” Primary DistributionPlant “X” Primary Distribution

In the outdoor switchyard two power transformers reduce the 120 kV from the utility to 13.2 kV

The main transformers are oil filled, fan cooled, and are rated for a max load of 24/32/40 MVA



Plant “X” Primary DistributionPlant “X” Primary Distribution The two Utility

transformers distribute 13.2 kV to the primary substation

Secondary selective design consisting of:

– Two main 2000A breakers

– A 2000A tie breaker

– Eight feeder breakers

– Two main busses, 1000 and 2000




FDR 1004

Subs21C

22C 23C 24C

FDR 1003

Subs21A

22A 23A 24A

FDR 1002

Sub 8E

FDR 1001 P/H

Main Bus 1

FDR 2002 Sub 8D

FDR 2003

Subs21B

22B 23B 24B

FDR 2004 Subs 21D 22D 23D 24D

FDR 2001 P/H

Main Bus 2




Each breaker enclosure door contains its associated

– Relays

– Power monitoring

– Control circuits allowing for breaker operation with the door closed via a toggle switch mounted on the door




The circuit breakers in the primary substation are 15kV “General Electric Power Vac” Vacuum circuit breakers

The operation and maintenance of these breakers will be discussed later in this course



Plant “X” Primary DistributionPlant “X” Primary Distribution The 13.2kV

substation in the powerhouse is a similar arrangement to the primary substation that was just discussed

Two main breakers feed busses 1 and 2 that each has 7 feeder breakers for distribution

Bus 1 and 2 are connected via a tie breaker.




Breakers are ITE/BBC 15HK air circuit breakers

Control power for these breakers is provided by a 125VDC-battery system located in the substation

FrontRear




This battery system needs to be kept on line at all times in order for the breakers to trip open under fault conditions

Battery system maintenance will be discussed in chapter 3

The battery is maintained on a 130V “Float charge” by the battery-charging unit mounted on the wall



Power Plus EngineeringPower Plus Engineering IBEW Local 58

NETA Certified Technicians

Complete Service of power distribution equipment

Engineering Services

Customized Training Courses Available including:– Substation Safety and Operation

– Substation Maintenance

– LV Circuit Breaker Maintenance

(248) 344-0200

www.epowerplus.com



POWER PLUS Engineering is a professional full service electrical testing and maintenance firm here to solve all of your AC and DC equipment and system needs

A large number of Michigan, Ohio and Indiana customers rely on POWER PLUS expertise to maintain and repair their electrical distribution systems and emergency power equipment.

POWER PLUS was founded in 1985 and specializes in AC and DC electrical equipment, systems and training.

POWER PLUS is a “Full Member In Good Standing” of the International Electrical Testing Association (NETA), is signatory to IBEW Local 58 and long-time member of the Construction Association of Michigan (CAM).

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Power Plus Training Services An introduction to our training programs