Updates to 2014 NEC


Figure 3: Modular data centers allow the use of outside air in the cooling systems, thereby limiting the use of air conditioning during colder months in cool climates. The HP EcoPOD modular data center is an example of a developing trend in data center architecture. Courtesy: HP400.7 Uses Permitted The proposed change to Article 400 (Flexible Cords and Cables) would allow use of a flexible cord or cable for connection of accessory equipment associated with mechanical equipment, alarms, or antennas. The nondetachable power supply cord must be 6 ft or less and the equipment must be above an accessible ceiling or dropped ceiling to meet this intent. Also, the installation shall not be prohibited by 300.22 to qualify as a permitted use.

404.2(C) Switches Controlling Lighting Loads A new proposed exception would exempt switch locations (from providing a grounded circuit conductor at the switch location) where snap switches with integral enclosures complying with 300.15(E) control the lighting loads.

Another exception would exempt the grounded circuit conductor requirement, such that where multiple switches (e.g., three- or four-way) control the same lighting load in an interior room or space, the grounded circuit conductor shall not be required at each location if one has been provided at one or more switching points visible from most areas within the room.

406.3(E) Controlled Receptacle Marking This new subdivision would require the use of a new marking symbol for receptacles that are controlled by an automatic control device or BAS. The requirement applies to nonlocking-type 125 V, 15 A and 20 A receptacles. Note that in the 2010 version of ASHRAE 90.1, 50% of all 125 V, 15 A and 20 A receptacles shall be controlled by an automatic control device for private offices, open offices, and computer classrooms (this includes receptacles in modular partition walls). As the new energy codes and future versions of U.S. Green Building Council LEED are adopted, this receptacle marking requirement will become much more prevalent.

406.5 Receptacle Mounting One change to this section would clarify that drywall screws shall not be used to fasten receptacles to boxes.

Currently receptacles mounted in countertops and similar work surfaces are not permitted to be mounted in the face-up position in dwelling units. Another proposed change would expand this restriction to apply to all occupancies.

A new subdivision would require that receptacles installed in floors, seating areas, and other similar surfaces may only be installed in a face-up position if the assembly is listed for that application.

406.15 Dimmer Controlled Receptacles A new section would clarify that a receptacle supply lighting load shall only be connected to a dimmer if the plug and receptacle combination is a nonstandard configuration type that is specifically listed and identified for each such unique combination.

410.6 Listing Required In addition to luminaires and lampholders, this amendment would require that retrofit kits be listed.

410.10(F) Luminaires Installed in or Under Roof Decking This new subdivision would restrict luminaires from being installed within 1.5 in. from the lowest surface of metal-corrugated sheet roof decking. The restriction is already in place for cables, raceways, and boxes (300.4(E)), but this change would extend the restriction to luminaires. The intent is to limit physical damage to the luminaire and its associated equipment (e.g., ballast and transformer) when screws and fasteners are added to repair or replace the roof decking, membrane, and insulating materials.

440.9 Grounding and Bonding, Air-Conditioning and Refrigerating Equipment A new section would require that an equipment grounding conductor be provided where air conditioning and refrigerating equipment is installed outdoors with either liquidtight flexible nonmetallic conduit (type LFMC) or electrical metallic tubing (type EMT). A related change to 350.60 would require that a wire-type equipment grounding conductor be installed for outdoor HVAC installations using LFMC, with exception requirements listed for industrial, commercial, and institutional installations.

445.11 Marking, Generators Additional marking would now be required by the generator manufacturer indicating whether or not the neutral is bonded to the generator frame. If the bonding is field-modified, additional marking would be required to again indicate whether or not the neutral is bonded to the generator frame.

445.20 GFCI Protection for Receptacles on Portable Generators A new section would require that all 125 V, 15 A and 20 A receptacles that are part of a 15 kW or smaller, portable generator have GFCI protection. The GFCI protection shall be integral to the generator or receptacle. The intent is to reduce possibilities of shock hazards for use of portable generators in less than ideal conditions.

490.25 Backfeed A proposed new section in Article 490 (Equipment, Over 600 V, Nominal) would add the following signage requirements to installations over 600V where the possibility of backfeed exists:

(a) A permanent sign in accordance with 110.21(B) shall be installed on the disconnecting means enclosure or immediately adjacent to open disconnecting means with the following words or equivalent: “DANGER — CONTACTS ON EITHER SIDE OF THIS DEVICE MAY BE ENERGIZED BY BACKFEED.”

(b) A permanent and legible single-line diagram of the local switching arrangement, clearly identifying each point of connection to the high-voltage section, shall be provided within sight of each point of connection.

517.18(B) Patient Bed Location Receptacles In the 2011 NEC, patient bed locations for general care areas are required to have a minimum of four receptacles, which shall be hospital-grade single, duplex, or quadruplex type, or any combination of the three. The proposed change for 2014 would increase this requirement to eight receptacles. The substantiation for the change is to coordinate requirements between the NEC and NFPA 99, Heath Care Facilities Code.

517.19(B) Patient Bed Location Receptacles In the 2011 NEC, patient bed locations for critical care areas are required to have a minimum of six receptacles. The proposed change for 2014 would increase this requirement to fourteen receptacles, with a minimum of one of the receptacles to be connected to either the normal system branch or the critical system branch. Again, the substantiation for the change is to coordinate requirements between the NEC and NFPA 99, and the receptacles shall be hospital-grade single, duplex, or quadruplex type, or any combination of the three.

517.19(C) Operating Room Receptacles A new subdivision would list receptacle requirements for operating rooms, A minimum of 36 receptacles would be required in each operating room, with a minimum of 12 receptacles on either the normal system branch or the critical system branch. Receptacles shall be hospital-grade single, duplex, or a combination of both.

625 Electric Vehicle Charging and Supply Equipment Systems This article would be renamed and reorganized with several changes, the most notable of which are as follows. Definitions for “electric vehicle charging system” and “electric vehicle supply equipment system” have been added (625.2). Where an automatic load management system is used, the maximum electric vehicle supply equipment load on a service or feeder would be limited to the maximum load permitted by the automatic load management system (625.12). A new section (625.17) lists requirements for cords and cables (e.g., types, ratings, lengths). Electric vehicle branch circuits would be required to be labeled, “For use with electric vehicle supply equipment (or electric vehicle charging system)” (625.30). Requirements would also be expanded for cord and plug supply equipment connections (625.44).

Figure 4: Electric vehicle charging systems provide a convenient means to charge vehicles that plug in instead of fueling up. Proposed changes to the NEC list additional requirements for these systems. Courtesy: GE690.12 Arrays on Buildings Response to Emergency Shutdown A new section in Article 690 (Solar Photovoltaic Systems) is proposed to increase the electrical and fire safety of photovoltaic (PV) systems on buildings—in particular, for the emergency responders working on power lines that may potentially contain live PV circuits. For PV systems installed on roofs of buildings, PV source circuits would be required to be de-energized within 10 seconds of when emergency shutdown is initiated or when the PV power source disconnecting means is opened. Additionally, the voltage at the module and module connectors shall be limited to 80 V or less when the source circuits are de-energized.

700.19 Multi-wire Branch Circuits A proposed new section to Article 700 (Emergency Systems) would prohibit emergency lighting and power branch circuits from being part of a multi-wire branch circuit. The intent is to prevent the unnecessary opening of the other one or two poles of a multi-wire branch circuit because of an overload, ground fault, or short-circuit on one pole of the multi-wire branch circuit. Prohibiting multi-wire branch circuits for emergency lighting and power branch circuits would prevent a trip in one emergency circuit from otherwise unnecessarily tripping other circuits, due to the circuit being supplied by either a multi-pole circuit breaker or single-pole circuit breakers sharing a common handle tie.

More Information

This article is meant to highlight some of the more important proposed changes of interest to consultants and specifiers. The changes listed are also limited to those that are currently listed as accepted in the RPO. As the list in this article is not comprehensive, there may be other substantive and important changes relevant to your field of work. Please review the 2013 ROP for more information, including all of the proposed changes.

Justin Schultz is a lead electrical engineer at Metro CD Engineering and serves as education chairman and board member for his local Illuminating Engineering Society (IES) section. He is a 2011 Consulting-Specifying Engineer 40 Under 40 winner.

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