View
843
Download
6
Category
Tags:
Preview:
Citation preview
Analysis of Changes – 2011 NEC
Training Presentation by:
International Association of Electrical Inspectors
Part 1 of 2 – NEC Chapters 1 – 4
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Code-Wide Changes
• There were approximately 5,016 proposals and 2,910 public comments submitted for modifications to the 2011 edition of the NEC
• “Fine Print Notes” have been changed and are now referred to as “Informational Notes” throughout the Code
• The term “grounding conductor” was replaced with the term “grounding electrode conductor,” “bonding jumper,” or “bonding conductor” in several places throughout the NEC
• Three new articles added to the 2011 NEC
Copyri
gh
t © IA
EI 2011Code-Wide Changes (cont.)
• Three new articles added to the 2011 NEC
– Article 399 - Outdoor, Overhead Conductors, Over 600 Volts
– Article 694 - Small Wind Electric Systems
– Article 840 - Premises-Powered Broadband Communications
Systems
Copyri
gh
t © IA
EI 2011
90.5(C) and (D) Explanatory Material and Informative Annexes
• “Fine Print Notes” are now referred to as “Informational Notes”
• This revision will more clearly define the adoptable and enforceable requirements of the NEC from these non-mandatory, but important forms of information
• The term "fine print" in some legal documents does not necessarily make the text unenforceable requirements
• New subdivision (D) (Informative Annexes) has been added referencing the informational annexes contained in the NEC
• Nonmandatory information relative to the use of the NEC is provided in informative annexes
Copyri
gh
t © IA
EI 2011
Copyr i
ght©
IA
EI 2
01
1
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Article 100 - Definitions
• Definitions of “Automatic” and “Nonautomatic” have been revised
– Automatic - Performing a function without the necessity of human intervention
– 2008 NEC : Self-acting, operating by its own mechanism when actuated by some impersonal influence, as, for example, a change in current, pressure, temperature, or mechanical configuration
– Nonautomatic - Requiring human intervention to perform a function
– 2008 NEC : Action requiring personal intervention for its control. As applied to an electric controller, nonautomatic control does not necessarily imply a manual controller, but only that personal intervention is necessary
Copyri
gh
t © IA
EI 2011
Automatic Nonautomatic
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Article 100 - Definitions
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Article 100 - Definitions
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Definitions related to services were added or revised in Article 100 to
clarify when these definitions are
covered under the scope of the NEC
Copyri
gh
t © IA
EI 2011
Article 100 - Service Definitions
• Service Conductors, Overhead - The overhead conductors between the service point and the first point of connection to the service-entrance conductors at the building or other structure
• Service Conductors, Underground - The underground conductors between the service point and the first point of connection to the service-entrance conductors in a terminal box, meter or other enclosure, inside or outside the building wall
• Informational Note: Where there is no terminal box, meter, or other enclosure, the point of connection is considered to be the point of entrance of the service conductors into the building
Copyri
gh
t © IA
EI 2011
Article 100 - Service Definitions (cont.)
Copyri
gh
t © IA
EI 2011
Article 100 - Service Definitions (cont.)
• Service-Entrance Conductors, Underground System - The service conductors between the terminals of the service equipment and the point of connection to the service lateral or underground service conductors
• Informational Note: Where service equipment is located outside the building walls, there may be no service-entrance conductors or they may be entirely outside the building
Copyri
gh
t © IA
EI 2011
Article 100 - Service Definitions (cont.)
• Service Lateral - The underground conductors between the utility electric supply system and the service point
• Service Point - The point of connection between the facilities of the serving utility and the premises wiring
• Informational Note: The service point can be described as the point of demarcation between where the serving utility ends and the premises wiring begins. The serving utility generally specifies the location of the service point based on their conditions of service
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
New definition and accompanying Informational Note added for Uninterruptible Power Supply (UPS)
Copyri
gh
t © IA
EI 2011
Article 100 - Definitions
• Uninterruptible Power Supply - A power supply used to provide alternating current power to a load for some period of time in the event of a power failure
• Informational Note: In addition, it may provide a more constant voltage and frequency supply to the load, reducing the effects of voltage and frequency variations
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
110.3(A)(1) Examination of Equipment
• Information related to special conditions of equipment has been added to the Informational Note
(A) Examination. In judging equipment, considerations such as the following shall be evaluated:
(1) Suitability for installation and use in conformity with the provisions of this Code.
Informational Note: Suitability of equipment use may be identified by a description marked on or provided with a product to identify the suitability of the product for a specific purpose, environment, or application. Special conditions of use or other limitations and other pertinent information may be marked on the equipment, included in the product instructions or included in the appropriate listing and labeling information.
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
110.28 Enclosure Types
• List of items that are required to be marked with an enclosure-type number from Table 110.28 have been expanded
• 110.28 relocated from 110.20
• Enclosures of switchboards, panelboards, industrial control panels, motor control centers, meter sockets, enclosed switches, transfer switches, power outlets, circuit breakers, adjustable-speed drive systems, pullout switches, portable power distribution equipment, termination boxes, general purpose transformers, fire pump controllers, fire pump motors, and motor controllers shall be marked with an enclosure-type number as shown in Table 110.28
Copyri
gh
t © IA
EI 2011
Cat. No. HNF361R
30 Amps Maximum
NEMA Type 3R
Copyri
gh
t © IA
EI 2011
Requirements for electrical equipment located in electrical vaults have been rearranged and expanded for usability
110.31(A) Electrical Vaults110.31(A) Electrical Vaults
Copyri
gh
t © IA
EI 2011110.31(A) Electrical Vaults
• Where an electrical vault is required or specified for conductors and equipment operating at over 600 volts, nominal, the following shall apply:
– Walls and Roof (Revised)• Constructed of materials of adequate structural
strength for the conditions• Minimum fire rating of 3 hours• Studs and wallboard construction not permitted
– Floors (Revised)• Concrete not less than 102 mm (4 in.) thick
(contact with the earth)• Otherwise, adequate structural strength for the
load imposed and minimum fire resistance of 3 hrs
Copyri
gh
t © IA
EI 2011
110.31(A) Electrical Vaults (cont.)
• Where an electrical vault is required or specified for conductors and equipment operating at over 600 volts, nominal, the following shall apply:
– Doors (New)
• Doorway from building interior to be provided with a tight-fitting door (minimum fire rating 3 hrs)
• AHJ permitted to require such a door for an exterior wall opening where conditions warrant
• Where the vault is protected with automatic sprinkler, water spray, carbon dioxide, or halon, construction of 1-hour rating permitted for walls, floors, and doors
Copyri
gh
t © IA
EI 2011
110.31(A) Electrical Vaults (cont.)
• Where an electrical vault is required or specified for conductors and equipment operating at over 600 volts, nominal, the following shall apply:
– Locks (New)
• Doors to be equipped with locks
• Doors to be kept locked
• Access only to qualified persons
• Personnel doors to swing out and be equipped with panic bars, pressure plates, or other devices that are normally latched but open under simple pressure
Copyri
gh
t © IA
EI 2011
110.31(A) Electrical Vaults (cont.)
• Where an electrical vault is required or specified for conductors and equipment operating at over 600 volts, nominal, the following shall apply:
– Transformers (New)
• Where a transformer is installed in a vault, the vault must be constructed in accordance with Part III of Article 450
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyr i
ght©
IA
EI 2
01
1
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
200.2 Use and ID of Grounded Conductors
• 2008 NEC
– All premises wiring systems, other than circuits and systems exempted or prohibited by 210.10, 215.7, 250.21, 250.22, 250.162, 503.155, 517.63, 668.11, 668.21, and 690.41, Exception, shall have a grounded conductor that is identified in accordance with 200.6. The grounded conductor shall comply with 200.2(A) and (B).
• 2011 NEC
– Grounded conductors shall comply with 200.2(A) and (B).
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
210.8(B)(5), Ex. No. 2 to(5) GFCI - Sinks
• Receptacles located around sinks at a dentist’s or doctor’s office or clinic do require GFCI protection
– (B) Other Than Dwelling Units - All 125-volt, single-phase, 15- and 20-ampere receptacles installed in the locations specified in (1) through (8) shall have ground-fault circuit-interrupter protection for personnel
– (5) Sinks — where receptacles are installed within 1.8 m (6 ft) of the outside edge of the sink
– Exception No 2 to (5): For receptacles located in patient bed locations of general care or critical care areas of health care facilities other than those covered under 210.8(B)(1) (Bathrooms), GFCI protection shall not be required
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
210.8(B)(7) GFCI - Locker Rooms
• Receptacles installed in locker rooms now require GFCI protection
– (B) Other Than Dwelling Units. All 125-volt, single-phase, 15- and 20-ampere receptacles installed in the locations specified in (1) through (8) shall have ground-fault circuit-interrupter protection for personnel.
– (7) Locker rooms with associated showering facilities
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011210.52(C)(5) and 210.52(D)
• Dwelling Unit Receptacle Outlet Locations:
– Listed receptacle outlet assemblies are now permitted to be installed on or in kitchen and bathroom countertops to serve as the required countertop receptacles
– Receptacle outlets must be located on, or above the countertop
– Applies to countertops in bathrooms, kitchens, pantries, breakfast rooms, dining rooms, and similar areas of dwelling units
– Receptacles shall not be installed in a face-up position in countertops or similar work surfaces [406.5(E)]
Copyri
gh
t © IA
EI 2011
Courtesy of Thomas & Betts Corp.
Copyri
gh
t © IA
EI 2011
Courtesy of Thomas & Betts Corp.
Copyri
gh
t © IA
EI 2011
210.52(E)(3) Balconies, Decks, and Porches
• Balconies, decks, and porches that are accessible from inside the dwelling unit required to have at least one receptacle outlet installed within the perimeter of the balcony, deck, or porch (regardless of size)
• Receptacle not be located more than 2.0 m (6½ ft) above the balcony, deck, or porch surface
• Exception for balconies, decks, or porches with a usable area of less than 1.86 m2 (20 ft2) has been deleted
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Article 225 – Outside Branch CircuitsFeeders – Part III Over 600 Volts
• 225.50 Sizing of Conductors
• 225.51 Isolating Switches
• 225.52 Disconnecting Means
(A) Location
(B) Type
(C) Locking
(D) Indicating
(E) Uniform Position
(F) Identification
Copyri
gh
t © IA
EI 2011
Article 225 – Outside Branch CircuitsFeeders – Part III Over 600 Volts (cont.)
• 225.56 Inspections and Tests
(A) Pre-Energization and Operating Tests
(1) Instrument Transformers
(2) Protective Relays
(3) Switching Circuits
(4) Control and Signal Circuits
(5) Metering Circuits
(6) Acceptance Tests
(7) Relays and Metering Utilizing Phase Differences
(B) Test Report
Copyri
gh
t © IA
EI 2011
Article 225 – Outside Branch CircuitsFeeders – Part III Over 600 Volts (cont.)
• 225.60 Clearances over Roadways, Walkways, Rail, Water, and Open Land
(A) 22 kV, Nominal, to Ground or Less
(B) Over 22 kV Nominal to Ground
(C) Special Cases
• Table 225.60 Clearances over Roadways, Walkways, Rail, Water, and Open Land
• 225.61 Clearances over Buildings and Other Structures
(A) 22 kV Nominal to Ground or Less
(B) Over 22 kV Nominal to Ground
• Table 225.61 Clearances over Buildings and Other Structures
Copyri
gh
t © IA
EI 2011
Article 225 – Outside Branch CircuitsFeeders – Part III Over 600 Volts (cont.)
• 225.70 Substations
(A) Warning Signs
(1) General
(2) Isolating Equipment
(3) Fuse Locations
(4) Backfeed
(5) Metal Enclosed and Metal Clad Switchgear
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
225.18 Clearance of Overhead Conductors
• Overhead spans of open conductors and open multiconductor cables (not over 600 volts) shall have a clearance of not less than the following:
– 3.0 m (10 ft) - above finished grade, sidewalks, etc. (not to exceed 150 volts)
– 3.7 m (12 ft) - over residential property and driveways, and commercial areas not subject to truck traffic (not exceed 300 volts)
– 4.5 m (15 ft) - areas listed in 3.7-m (12 ft) classification (voltage exceeds 300 volts to ground)
– 5.5 m (18 ft) - over public streets, alleys, roads, etc.
– 7.5 m (24.5 ft) - over track rails of railroads
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
230.24(A) Ex. No. 5 Clearance Above Roofs
• Service conductors generally required to have a vertical clearance not less than 2.5 m (8 ft) above roof surface
• Exception No. 5: Where the voltage between conductors does not exceed 300 and the roof area is guarded or isolated, a reduction in clearance to 900 mm (3 ft) shall be permitted
• Guarded — Covered, shielded, fenced, enclosed, or otherwise protected by means of suitable covers, casings, barriers, rails, screens, mats, or platforms to remove the likelihood of approach or contact by persons or objects to a point of danger.
• Isolated (as applied to location) — Not readily accessible to persons unless special means for access are used.
Copyri
gh
t © IA
EI 2011
230.42(A)(1) Ex. Size and Rating of Service
• The ampacity of service-entrance conductors (before any adjustment or correction factors) shall not be less than either of the following:
– The sum of the noncontinuous loads plus 125 percent of continuous loads
– The sum of the noncontinuous load plus the continuous load if terminated in an overcurrent device (where both overcurrent device and assembly are listed for operation at 100 percent of their rating)
• Exception: Grounded conductors not connected to an overcurrent device permitted to be sized at 100 percent of the continuous and noncontinuous load
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
240.15(B) Circuit Breakers as OCP
• Circuit breakers must open all ungrounded conductors of the circuit unless otherwise permitted by the following:
– Individual single-pole circuit breakers (with identified handle ties) of multiwire branch circuits permitted as OCP serving only single-phase line-to-neutral loads
– In grounded systems, individual single-pole circuit breakers rated 120/240 volts ac (identified handle ties) permitted as OCP for line-to-line connected loads for single-phase circuits
Copyri
gh
t © IA
EI 2011
240.15(B) Circuit Breakers as OCP (cont.)
• Circuit breakers must open all ungrounded conductors of the circuit unless otherwise permitted by the following:
– For 4-wire, 3-phase systems or 5-wire, 2-phase systems, individual single-pole circuit breakers rated 120/240 volts ac (identified handle ties) permitted as OCP if the systems have a grounded neutral point and the voltage to ground does not exceed 120 volts
– Individual single-pole circuit breakers rated 125/250 volts dc (identified handle ties) permitted as OCP for 3-wire, direct-current circuits supplied from a system with a grounded neutral where the voltage to ground does not exceed 125 volts
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
240.91 Protection of Conductors -Supervised Industrial Installations
• New provisions were added for limited “round up” conductor protection with overcurrent devices
– rated over 800 amperes
– in supervised industrial installations
Copyri
gh
t © IA
EI 2011
240.91 Protection of Conductors -Supervised Industrial Installations
• Conductors shall be protected by the following:
– (A) General - Conductors to be protected per 240.4
– (B) Devices Rated over 800 Amperes - Where the overcurrent device is rated over 800 amperes, the ampacity of the conductors it protects must be equal to or greater than 95% of the rating of the OCD defined in 240.6 where:
- (1) the conductors are protected within recognized time vs. current limits for short-circuit currents and
- (2) where all equipment in which the conductors terminate is listed and marked for the application
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
250.2 Definition: Supply Side Bonding Jumper
• New definition for “Supply Side Bonding Jumper” was added to 250.2
• SSBJ also introduced at 250.30(A)(2) for grounding of separately derived AC systems
• In the previous edition of the Code, the term “equipment bonding jumper” was used
• New definition of SSBJ necessary to ensure the proper identification and installation of bonding conductors installed within or on the supply side of service equipment and between the source of a separately derived system and the first disconnecting means
• Equipment bonding jumpers are installed on the load side of the overcurrent device
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
250.24(C) Grounded Conductor Brought to Service
• Rules for routing the grounded conductor at service equipment have been revised for clarity
• Requirements on routing the grounded conductor with ungrounded conductors were moved to 250.24(C) from Item (1) to clearly indicate that this routing rule applies to single or parallel raceways
• Separate sub-sections have been created for applications installed in a single raceway and conductors installed in parallel in separate raceways
• Rules for sizing grounded conductor of 3-phase systems have been located in a new Item (3)
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
250.64(B) Securing and Protection - GECs
• Where exposed, a grounding electrode conductor (GEC) or its enclosure shall be securely fastened to the surface on which it is carried
• GECs shall be permitted to be installed on or through framing members
• 4 AWG or larger copper or aluminum GEC must be protected if exposed to physical damage
• 6 AWG GEC free from exposure to physical damage permitted to be run along the surface of a building without metal covering or protection (if securely fastened to the construction)
• See 250.64(B) for list of acceptable wiring methods to provide physical protection
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
250.92(B) Method of Bonding at Service
• Bonding requirements were added for bonding around reducer washers at raceways containing service conductors
• Bonding jumpers must be used around impaired connections such as reducing washers or oversized, concentric, or eccentric knockouts
• Standard locknuts or bushings cannot be the only means for the bonding at services but permitted to be installed to make a mechanical connection of the raceway(s)
• Electrical continuity at service equipment, service raceways, and service conductor enclosures shall be ensured by bonding equipment to the grounded service conductor, threaded couplings or threaded hubs, bonding-type locknuts, bonding bushings, etc.
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Table 250.122
• Sizing requirements for wire type equipment grounding conductors is governed by 250.122 and Table 250.122
• Revision with the deletion of the “30” and “40” amperes rows in Table 250.122
• The heading above the ampere column in the table states “Rating or Setting of Automatic Overcurrent Device in Circuit Ahead of Equipment, Conduit, etc., Not Exceeding (Amperes)”
• The “30” and “40” ampere figures were redundant and not needed
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Table 250.122
• The sizing requirement of an aluminum equipment grounding conductor for circuit conductors protected by a 4000-ampere rated overcurrent device was revised
• The minimum size for this aluminum equipment grounding conductor was changed from 800 kcmil to 750 kcmil
• A 500 kcmil copper conductor and a 750 kcmil aluminum conductor with equivalent insulation are equally capable of carrying the same fault current
• 750 kcmil aluminum conductors are a more common industry standard size than 800 kcmil
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
250.190 Grounding of Equipment 1 kV and Over (High Voltage)
250.190 Grounding of Equipment (A) Equipment Grounding (B) Grounding Electrode Conductor (C) Equipment Grounding Conductor
(1) General(2) Shielded Cables(3) Sizing
• Requirements for grounding of equipment of systems and circuits of 1 kV and over (high voltage) have been revised and expanded
• An EGC is required to be installed along with the medium voltage feeder conductors for solidly grounded systems
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyr i
ght©
IA
EI 2
01
1
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
300.11(A)(2) Non-Fire-Rated Assemblies
• New language was added requiring identification of independent wiring method support ceiling wires in non-fire-rated assemblies
• Previous language only required additional wiring method support wires to be distinguishably marked for fire-rated assemblies
• Acceptable identification methods could include such things as painting, tagging or other forms of identification
• This will also assist both installers and inspectors to be able to determine which support wires are acceptable for supporting wiring methods
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011Article 310 Ampacity Tables
• All tables located within Article 310 were renumbered in the 2011 NEC
• Article 310 (Conductors for General Wiring) went through extensive reorganization for the 2011 NEC
• This reorganization had an extreme impact on the tables within the article as well
• This was an effort to bring the table numbering in line with the NEC Style Manual
• NEC Style Manual Section 2.3.1 - “Tables and figures shall be referenced in the text and shall be designated by the number of the NEC rule in which they are referenced”
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
310.10(H)(1) Conductors in Parallel
• Revisions were made to the parallel conductors rules found at 310.10(H)(1) [previously 310.4(A)] pertaining to the minimum size conductors permitted to be run in parallel
• Previous language stated that conductors “1/0 AWG and larger shall be permitted” to be run in parallel
• The words “shall be permitted” did not act to prohibit the paralleling of smaller conductors
• This revision states more definitively that “only sizes 1/0 AWG and larger” are permitted to be run in parallel (without employing one of the two existing exceptions to the main rule)
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Table 310.15(B)(2)(a) Ambient Temperature Correction Factors Based
on 30°C (86°F)• The ambient temperature correction factor table
has been relocated from the bottom of previous Table 310.16 to a new Table 310.15(B)(2)(a)
• Temperature correction factors needed and will now have there own table
• All temperature applications now at one location as the other temperature correction factor tables previously located at the bottom of the other allowable ampacity tables were relocated to new Table 310.15(B)(2)(b)
• Ambient temperature correction factor tables were also expanded to include temperatures and correction factors below the ambient temperature of allowable ampacity tables
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Table 310.15(B)(3)(a) Adjustment Factors for More Than Three Current-Carrying Conductors in a Raceway or
Cable• Table 310.15(B)(3)(a) [formally Table 310.15(B)(2)
(a)] contains requirements for adjustment or derating of conductors where the number of current-carrying conductors in a raceway or cable exceeds three
• The first column heading has been changed from “Number of Current-Carrying Conductors” to “Number of Conductors”
• This will take into account “spare” conductors that might be installed in raceways for future expansion or use but are not yet “current-carrying” conductors
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
310.15(B)(3)(c) Circular Raceways Exposed to Sunlight on Rooftops
• Revisions were added to require all types of circular raceways to temperature correction factors of 310.15(B)(3)(c) (not just conduits)
• Previous language required conductors or cables installed in conduits exposed to direct sunlight on or above rooftops to be subject to these correction factors
• The term “conduit” was changed to “circular raceway” to indicate that all types of circular raceways are subject to these temperature correction factors
• The term “circular raceways” will include all wiring methods originally tested (such as EMT)
• The term “conduit” is not defined in the NEC; the term “circular raceways” is a broader, and more-encompassing
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Table 310.15(B)(16)
• Some of the ampacity values in Table 310.15(B)(16) (formally Table 310.16) were revised for the 2011 NEC
• These revised ampacity values were an effort to harmonize the ampacity values between NEC Table 310.15(B)(16) and Canadian Electrical Code (CEC) Tables 2 and 4 with technically substantiated ampacity values
• Proposals were submitted to correlate the CEC to the NEC on five minor deviations
• These revisions were generated by proposals from the NFPA/CSA NEC/CEC Ampacity Harmonization Task Group
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Table 310.60(C)(4)
• Table 310.60(C)(4) - Ambient Temperature Correction Factors for Conductors Rated 2001 to 35,000 Volts
• A new temperature correction factor table for conductors rated over 2000 volts was added at 310.60(C)(4)
• This new table will harmonize these ampacity correction factors between the NEC and the Canadian Electrical Code (CEC)
• Equation following 310.60(C)(4) was used to calculate these ampacity correction factors
• This new table was generated by the NFPA/CSA NEC/CEC Ampacity Harmonization Task Group
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
314.27(A) Boxes at Luminaires or Lampholders
• Revisions were made to the requirements for boxes at luminaires and lampholders for clarity
• Revision incorporates the provisions of previous 314.27(B) (Maximum Luminaire Weight) into the revised language of 314.27(1) and (A)(2)
• The requirements for wall-mounted and ceiling-mounted luminaires have been separated into separately numbered subsections
• Manufacturer marking requirements for maximum weight of luminaire support to be marked “on the interior of the box”
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
314.28(E) Power Distribution Blocks
• New provisions added to permit and provide guidelines for the installation of power distribution blocks in pull and junction boxes
• Basic minimum size pull and junction box permitted to contain power distribution blocks [1650 cm3 (100 in.3)]
• New provisions ensure that no shock hazard exists from exposed live terminal parts when the pull and junction box cover is removed
• These new provisions are similar to provisions that already exist in Article 376 for metal wireways
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
320.2 Definitions: Type AC Cable
• Armored Cable, Type AC. A fabricated assembly of insulated conductors in a flexible interlocked metallic armor. See 320.100
• The definition of Type AC cable has been revised
• Previous definition used the phrase flexible metallic “enclosure” for containing the insulated conductors of this wiring method
• “Enclosure” missed the mark entirely in describing Type AC cable
• New language replaces “flexible metallic enclosure” with “flexible interlocked metallic armor”
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
328.14 Medium Voltage Cable: Type MV
• Type MV cable is now required to be installed, terminated and tested by qualified persons
• Type MV cable installations have typically been under the authority of licensed utilities (typically above 600 volts), and under the supervision of the engineering community
• New language should heighten the awareness to installers and AHJs concerning the inherent dangers with installations at these higher voltages that may not be apparent to the untrained eye
• The NEC typically requires more specific qualifications for special equipment and systems that require highly trained and knowledgeable installers
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
334.10(1) Uses Permitted – Type NM Cable
• Type NM cable can now be used in attached or detached garages, and one- and two-family dwelling storage buildings without concealment behind a finished 15-minute rating thermal barrier
• Previous language permitted Type NM cable as an exposed wiring method at an attached garage, but not a detached garage
• The perception that the installation of Type NM cable in these detached accessory buildings somehow constituted a greater hazard than the dwelling unit structure itself seemed excessive to many users of the Code
• Note: “attached and detached garages and their storage buildings” are not children’s play houses, and other similar structures, which may invite increased use
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
342.30 Securing and Supporting Raceways
• Short raceways [450 mm (18 in.) to 900 mm (36 in.)] no longer require additional support
• In previous language, the existence of a coupling in a short conduit nipple instantaneously provoked a support requirement for this conduit
• Raceways generally require support within 900 mm (3 ft) of terminations; when entire length is just that long or shorter, no additional support should be needed
• This section was revised into a list format to make this section more user-friendly
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
342.30 Securing and Supporting Raceways
• The deletion of the “Unsupported Raceways” language was uniformly made to five (5) conduit articles:
342.30(C) Intermediate Metal Conduit (IMC)
344.30(C) Rigid Metal Conduit (RMC)
352.30(C) Rigid Polyvinyl Chloride Conduit (PVC)
355.30(C) Reinforced Thermosetting Resin Conduit (RTRC)
358.30(C) Electrical Metallic Tubing (EMT)
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
348.42 Couplings and Connectors (FMC)
• Angle connectors for flexible meta conduit cannot be installed where the angle connector itself will be concealed
• Previous language may have been construed to restrict the use of an angle connector if the raceway to which the angle connector is attached is all or even partially concealed
• Revision will make it clear which portion of the raceway installation is not permitted to be concealed (angle connector itself)
• Same change occurred at 350.42 for liquidtight flexible metal conduit (LFMC)
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Courtesy of CANTEX Forte-Duct
Copyri
gh
t © IA
EI 2011
353.10(6) Uses Permitted (HDPE)
• A new Item (6) for “Uses Permitted” for HDPE conduit was added for temperature rating of conductors used with HDPE
• Previous language was an Item (5) and an exception to Item (5) of the “Uses Not Permitted” in the 2008 NEC
• The new language writes the previous exception into permissive text
• Moving the conductor operating temperature requirements to “Uses Permitted” makes it clear that conductors marked with a rated temperature higher than HDPE raceway can be used when the conductors are operated within the HDPE raceway temperature rating (not the higher rating of the conductor)
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
368.10(B) Busways Behind Access Panels
• Busways are permitted to be installed behind access panels
• Previous title of “Concealed” was changed to “Behind Access Panels”
• Busways were previously permitted to be installed behind an access panel, but meeting the definition of “concealed” was difficult at best
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyr i
ght©
IA
EI 2
01
1
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
404.2(C) Switches for Lighting Outlets
• Generally, where switches control lighting loads from a grounded general-purpose branch circuit, the grounded circuit conductor for the controlled lighting circuit must be present at the switch location
• Many electronic lighting control devices, such as occupancy sensors require standby current to maintain a ready state of detection for the function of these devices
• Note: See exceptions for boxes feed by raceways and cable assembly boxes with framing cavity open at the top or bottom on the same floor level, or wall, floor, or ceilings unfinished on one side
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
406.9(B)(1) Receptacles in Wet Locations
• All 15- and 20-ampere, 125- and 250-volt receptacles installed in a wet location must have an enclosure that is weatherproof whether or not the attachment plug cap is inserted (in-use cover)
• For other than one- or two-family dwellings, an outlet box hood installed for this purpose shall be listed and where installed on an enclosure supported from grade must be identified as “extra-duty”
• All 15- and 20-ampere, 125- and 250-volt nonlocking type receptacles must be listed weather-resistant type
Copyri
gh
t © IA
EI 2011
Example of “extra-duty” type outlet box hood
Note: Enclosure not supported from grade
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011409.104(A) Wiring Space (Industrial Control Panels)
• Other equipment (other than switches or overcurrent devices) permitted to be installed in industrial control panels with adequate wire bending space provided
• The term “other equipment” added here to accommodate other types of devices and equipment (other than switches or overcurrent devices) which are installed in industrial control panels
• Previous language indicated that an industrial control panel could serve as a junction box for conductors tapped off of something like a contactor without adequate wire bending space provided
• “Other equipment” could include such things as terminal blocks, control transformers, and relays
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
422.30 Disconnecting Means for Appliances
• “Simultaneously” was added to the disconnecting means requirements for appliance
• Required appliance disconnecting means is to disconnect all the ungrounded conductors of each appliance at the same time (simultaneously)
• Previous language identified that an appliance could be supplied by more than one source
• Revision clearly identifies these sources as either a branch circuit or feeder
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
422.31 Disconnecting Means for Appliances
• Disconnecting means requirements when an appliance contains a motor over 1/8 hp have been revised and clarified
• Previous requirements of 422.32 (disconnecting mean for motor-driven appliances) have been deleted and rolled into the revisions of 422.31(C)
• Previous 422.32 prohibited the capability of an appliance rated over 1/8 hp to be locked in the open position
• “Over 1/8 hp” has been removed from 422.31(B) and a new 422.31(C) has been created to address appliances rated over 1/8 hp
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
424.44(G) Heating Cables in Floors
• GFCI protection now required for cables installed in electrically heated floors of kitchens as well as in bathrooms and in hydromassage bathtub locations
• GFCI protection of electrical heating cables in kitchen masonry floors should include the same GFCI protection currently provided in bathrooms and hydromassage tub locations
• This GFCI protection will help reduce shock hazards to persons in contact with these heated floors
• This GFCI requirement applies regardless of the type of floor covering over the concrete or poured masonry such as wood, vinyl, or ceramic tile
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011426.28 GFP of Equipment
• The elimination of ground-fault protection of fixed outdoor electric deicing and snow-melting equipment for mineral-insulated, metal-sheathed cable has been deleted (as permitted in previous editions of the Code)
• Mineral-insulated cables employ different types of metal sheaths, not all of which are suitable as ground-fault return paths
• Revisions to the title of 426.28 also occurred to match the subject content of this section (Ground-Fault Protection of Equipment)
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011430.53 Several Motors or
Loads on One Branch Circuit• Inverse time circuit breakers and fuses are the
only permitted means for providing group motor branch circuit short-circuit and ground-fault protection
• The Code permits more than one motor or motor(s) and other loads to be supplied with one branch circuit (with conditions)
• Instantaneous trip circuit breakers are not permitted to be used in group installations as coordination of these circuit breakers is typically very difficult, if not impossible to achieve when used in these group installations
• Clarifications to this section will help avoid misapplication of these types of devices
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
430.53(D)(3) Several Motors or Loads on One Branch Circuit – Single Motor
Tap• Branch-circuit protective devices are now
permitted to provide short-circuit and ground-fault protection for group motor installations and not required to be identified for group installations
• For group motor applications, 430.53(D)(3) permit tapping a branch circuit to supply a single motor
• These tap conductors are permitted to terminate in a listed manual motor controller that is marked “Suitable for Tap Conductor Protection in Group Installations”
• Revisions will now allow the branch-circuit protective device to provide short-circuit and ground-fault protection for group installations and not be required to be identified for group installations
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
445.19 Generators Supplying Multiple Loads
• Revision clarifies the application of tap conductors where multiple enclosures are supplied from a generator
• Generator(s) are now required overcurrent protection meeting the requirements of 240.15(A) (Overcurrent Device Required- Ungrounded Conductors) allowing the tap conductors to meet the definition of “Tap Conductors” at 240.2
• Feeder taps without overcurrent protection upstream is in conflict with the requirements described in 240.21 (Overcurrent Protection-Location in Circuit)
• Modern generators typically employ a listed overcurrent protective device integral with the control function
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
450.14 Disconnecting Means -Transformers
• New disconnecting means requirements added for transformers (other than Class 2 or Class 3)
• This brings transformers in line with other electrical apparatus with similar disconnecting means requirements such as motors, generators, appliances, air-conditioning equipment, etc.
• Intended to enhance safety for qualified electrical workers when they work with or perform maintenance on transformers
• Allows for a transformer to be isolated where there are multiple transformers tapped from a single feeder as permitted by 240.21(B)(3)
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Copyri
gh
t © IA
EI 2011
Analysis of Changes – 2011 NEC
Training Presentation by:
International Association of Electrical Inspectors
Recommended