What’s in Store for the 2008 NEC?
In the coming months the code-making panels of the National Fire Protection Assn. will review approximately 3,700 proposals to revise the current (2005) edition of NFPA 70, The National Electrical Code. Their recommendations will be presented to the NFPA membership at the annual meeting in Boston next June.
In the coming months the code-making panels of the National Fire Protection Assn. will review approximately 3,700 proposals to revise the current (2005) edition of NFPA 70, The National Electrical Code . Their recommendations will be presented to the NFPA membership at the annual meeting in Boston next June.
So what exactly is on the docket? Following is a snapshot of the major proposed changes:
Title 110.20 — Enclosure Types . Moves enclosure selection table from 430.91 to Article 110 and applies to 600-volt and less enclosures for: switchboards, panelboards, motor control centers, industrial control panels, meter sockets and motor controllers.
Title 110.26(C)(2) — Entrance to Working Space . Requires two entrances to the working space if the equipment is 1,200 amps or greater and the equipment is more than 6 ft. wide. Doors within 6 in. of the working space must have panic hardware and must open outward.
Title 210.4(A) & (B) — Multiwire Branch Circuits . This amendment addresses the requirements for simultaneous disconnect of all circuits, not just be those on same yoke but also and include other circuits such as lighting. Additionally, conductors must be grouped at one point in the panel (wire tie). Conductors must also be tagged to show which grounded conductor goes with which ungrounded conductor.
Title 210.8(A) — GFCI (Dwelling Units) . This proposal would delete the exceptions to (A)(2) and (A)(5) that allow non-GFCI-protected receptacles for dedicated appliances and receptacles that are not readily accessible. Furthermore, GFCI protection will now be required for all receptacles in the garage and unfinished basements. The exception for fire alarms, however, will remain in place.
Title 210.8(B) — GFCI (Other than Dwelling) . Requires GFCI protection expanded to all 125-volt, 15- and 20-amp receptacles installed within 6 in. of any sink.
Title 210.8(B) — GFCI (Other than Dwelling) .The requirement for GFCI has been expanded to all 125-volt, 15- and 20-amp receptacles installed outdoors, regardless of the occupancy or location. The exception is for industrial locations when they use the assured equipment grounding conductor program.
Title 210.12(B) — AFCI . AFCI expansion to include all 120-volt, 15- and 20-amp circuits in the dwelling.
Title 240.92(B) — Tap Conductor Short Circuit Ratings . This proposal adds new provisions to the “Supervised Industrial Installation” rules. In fact, it allows conductor size to be based on ICEA formulas (I2/A2) t = 0.0297 log10 [(T2 + 234)(T1 + 234)] where I = short circuit current in amperes; A = conductor area in circular mils; t = time of short circuit in seconds; T1 = initial conductor temperature; T2 = final conductor temperature.
Title 250.20(D) — Separately Derived Systems . Text has been added to make it clear that a generator installation with transfer equipment that switches the grounded conductor must be grounded in accordance with 250.30(A).
Title 250.122 — Size of Equipment Grounding Conductors . New text clarifies that when ungrounded conductors are increased in size for ampacity adjustment, the equipment-grounding conductors do not need to be increased proportionally.
Title 280 — Surge Arresters . Now applies only to arresters over 1 kV. Article 285 now also covers all surge-protective devices less than 1 kV.
Title 285 — Surge Protective Devices (SPD) . UL 1449 is currently under revision for 3rd Edition. The UL proposal would align NEC terminology with the UL standard, specifically for:
Type 1 — Line side of Service Disconnect
Type 2 — Load Side of Service Disconnect
Type 3 — Outlet device/Plug strips
Type 4 — Recognized Component
Title 310.15(B)(2)(c) — Conduits on Rooftops . Requires that the ambient temperature used for ampacity correction be adjusted by specified factors where conductors or cables are installed in conduit, the conduit is on or above a rooftop or the conduit is exposed to direct sunlight. The temperature requirements are as follows: zero to
Title 334.80 — NM Sheathed Cable: Type NM, NMC, NMS . Where more than two cables containing two or more current-carrying conductors (#12 AWG = 30A @ 90C; 8 conductors = 80% derating 30A x 0.8 = 24A), the penetration must be draft-stopped or fire-stopped with foam, caulk or thermal insulation.
Title 334.80 — Ampacity . Requires ampacity adjustment factors to be applied to NM cable where more than two cables—with two or more currentcarrying conductors—are installed without spacing, and the cables are installed in contact with thermal insulation.
Title 406.8(B)(1) — Wet Locations . Would require a receptacle that is listed as weather-resistant, effective by Jan. 1, 2011.
Title 408 — Panelboards . The 42-circuit restriction would be removed. That said, the product standard has requirements for Class CTL panels that will need to be addressed. Furthermore, product markings will restrict number of circuits until product standard is revised.
Title 430.126 — Overtemperature Protection . New language: A) General. Adjustable-speed drive systems shall protect against motor overtemperature conditions where the motor is not rated to operate at the nameplate-rated current over the speed range required by the application. Specifically:
– Motor thermal protector meeting 430.32
– Adjustable-speed drive system with load and speed sensitive overloadprotection
– Overtemperature protection relay utilizing thermal sensors embedded in the motor
– Thermal sensors embedded in the motor that communicate with the drive.
Title 490.27 — Metal-Enclosed and Metal-Clad Service Equipment . This proposal adds requirements for service conductor termination compartment as follows: hinged or bolted cover; markings; voltage testing provisions; ground bus; requirements where separable connectors are used. For service overcurrent devices, they must be designed so that they are de-energized while being replaced or maintained. Additionally, access to OCD shall not expose personnel to live parts
Article 519 — Control Systems for Permanent Amusement Attractions . This article covers the installation of control circuit power sources and conductors for electrical equipment, including associated control wiring in or on all structures, that are an integral part of a permanent amusement attraction.
Title 585 — Critical Operations Power Systems . Developed in response to Homeland Security activity, specifically steps beyond an emer-gency system examining requirements for how one keeps a system in operation for days.
Title 590.6 — Temporary Installations — GFCI . New text makes it clear that the GFCI provisions apply whether power is derived from a utility source or an on-site generator.
Title 702.5(2) — Automatic Transfer Equipment . If an automatic transfer is used in an optional system, the power source—typically a generator—must be able to pick up the full load transferred by the equipment; and a load-management system must be installed that will limit the load to that capable of being supplied by the source.
Title 760.41(B) — NPLFA Branch Circuit . Requires an individual branch circuit be used to supply the power source of the fire alarm system. There’s also a parallel requirement for 760.121(B) for power limited systems.
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