This article is a continuation of a concise and complete review of some of the more significant changes that have been incorporated into the 2014 edition of the National Electrical Code (NEC). This segment takes a look at some significant revisions in chapters 4 through 6. Not all of the 2014 Code changes are presented in this article, and the changes that are covered are provided in the numerical sequence in which they appear in the NEC. 

(Editor's Note: Click here to read part I of this series. Click here to read part II of this series.)

Chapter 4 Equipment for General Use

404.2(C) Grounded Conductor at Switch Locations

This section has been restructured into a list format, and the former exception has been incorporated into positive text. New list item (3) relaxes the grounded conductor requirement at switches with integral enclosures. New list item (5) relaxes the grounded conductor requirement in locations where multiple switches control the same lighting load. [ROP 9-44, 9-45, 9-46; ROC 9-87, 9-88, 9-89, 9-90, 9-91]

406.3(E) Marking for Controlled Receptacles

A new subdivision (E), Controlled Receptacle Marking, Exception, and associated figure been added to 406.3. This requirement applies to receptacles controlled by building automation or energy management systems. A specific power symbol marking must be applied to nonlocking type, 125-volt (V), 15- and 20-ampere (A) automatically controlled receptacle outlets and be visible after installation. [ROP 18-15; ROC 18-13]

406.5(E) and (F) Receptacles in the Face-Up Position

Subdivision (E) has been revised and expanded to all occupancies, and 210.8 ground-fault circuit interrupter (GFCI) protection applies. New Subdivision (F), Receptacles in Seating Areas or Similar Surfaces, states that receptacles installed in seating areas or similar surfaces are not permitted in the face-up position unless the installation meets one of list items (1) through (4). [ROP 18-32, 18-33, 18-34; ROC 18-23]

406.9(B)(1) Receptacles in Wet Locations

The words “other than one- and two-family dwellings” have been removed from this section. The text related to how the receptacle outlet is supported has also been removed from this section. Listed and identified extra-duty receptacle covers (hoods) are required for all 15- and 20A, 125- and 250V receptacles installed in a wet location. [ROP 18-37, 18-38]

408. 3(F)(3), (4), (5) Panelboards, Switchboards, and Switchgear Identification

Three list items have been added to 408.3(F) and the word “switchgear” has been added. Additional caution markings are now required for switchboards, switchgear and panelboards used with high-impedance grounded neutral systems, ungrounded direct current systems and resistance grounded direct current systems. The “caution” markings in list items (1) through (5) must comply with 110.21(B). [ROP 9-111, 9-103a; ROC 9-55, 9-58]

422.5 Ground-Fault Circuit-Interrupter Protection

Section 422.5, Ground-Fault Circuit Interrupter (GFCI) Protection, has been added to Part I of Article 422. GFCI protective devices installed for appliances covered by Article 422 must be readily accessible, which is consistent with the readily accessible requirements for GFCI devices in 210.8. [ROP 17-19, 17-42]

422.23 Tire Inflation and Automotive Vacuum Machines

Tire Inflation and Automotive Vacuum Machines, 422.23, has been added to Article 422. Tire inflation equipment or vacuum machine for public use must have GFCI protection for personnel. The GFCI protection (circuit breaker or outlet device) is required to be readily accessible. [ROP 17-31]

424.66 Installation

Subdivision (B), Limited Access, has been added to 424.66. The width and depth of working space in 110.26 is required in front of duct heater enclosures containing equipment that requires servicing while energized. The revision requires duct heater equipment enclosures to be located so as to provide the minimum clearances. [ROP 17-75; ROC 17-19]

445.20 Protection for Portable Generators

A new 445.20, Ground-Fault Circuit Interrupter Protection for Receptacles on 15 kW or Smaller, Portable Generators, has been added to Article 445. If a 15-kilowatt (kW) or smaller portable generator has a 125/250V locking receptacle, then all 125V, single-phase, 15- and 20A receptacles must have GFCI protection or not be usable when the 125/250V locking receptacle is in use. [ROP 13-19; ROC 13-19]

450.10(A) Dry-Type Transformer Enclosures

A new subdivision (A) and exception have been added to 450.10. This new provision provides specific requirements for grounding and bonding connections in transformer enclosures. A separate grounding terminal bar must now be installed but not on vented portions of the enclosure. [ROP 9-144]

480.9(D) and (E) Marking for Personnel Access to Energized Batteries and Egress

Two subdivisions have been added to 480.9: (D) Marking for Personnel Access to Energized Batteries and (E) Egress. Marking for battery rooms must meet the warning sign requirements in 110.27(C). Personnel doors for battery rooms must swing in the direction of egress and be equipped with listed panic hardware. [ROP 13-44, 13-45; ROC 13-26, 13-27]

490.25 Backfeed

A new 490.25, Backfeed, has been added to Part II of Article 490. The new requirement is for a sign that warns qualified people of the possibilities of contacts within the equipment being energized by backfeed. A reference to 110.21(B) has been provided for additional requirements related to danger signs installed on equipment. The specific text on the sign must read as follows: 


Chapter 5 Special Occupancies

501.15(C)(6) Fiber Optic Tubes Within a Seal

Optical fiber tubes (metallic or nonmetallic) are now recognized for installation in a seal, and they shall not exceed 25 percent of the cross-sectional area of a rigid metal conduit unless specifically marked otherwise. The cross-sectional area of the optical fiber tube(s) must be used, not that of the optical fibers themselves. Expanded cross-sectional area seals are readily available for use in fill applications up to and not exceeding 40 percent. These expanded sealing fittings are listed and identified. [ROP 14-48, 14-49, 14-172, 14-173, 14-174, 14-176; ROC none]

514.3(B)(1) Motor Fuel Dispensing and Aboveground Fuel Storage

Superscript note 2 to Table 514.3(B)(1) has been revised to refer to two figures. Existing Figure 514.3(a) has been revised to show a new below-grade sump classified area as Class I, Division 1. A new Figure 514.3(b) was added to show the classified area adjacent to a dispenser mounted on aboveground storage tanks. Both of the figures and associated text are extracted material from NFPA 30A 2012. [ROP 14-237] 

514.3(C) Motor Fuel Dispensing Stations in Boatyards and Marinas

All boat and marina motor fuel dispensing station requirements were relocated from Article 555, Marinas and Boatyards, to Article 514, Motor Fuel Dispensing Stations. New Section 514.3(C) is titled “Motor Fuel Dispensing Stations in Boatyards and Marinas.” All NEC requirements for boatyard and marina motor fuel dispensing facilities are under the purview of NEC Code-Making Panel 14. Section 555.21 now provides only a reference to Article 514 for the specific requirements for these fueling facilities in marinas and boatyards. [ROP 14-237]

517.18(B) Number of Receptacles in Normal Patient Bed Locations

The minimum number of receptacles required in a general care patient bed location has increased to eight. These receptacles must be listed and identified as “hospital grade” and connected to an insulated copper equipment grounding conductor. This revision aligns with the new requirements in Section (A) of NFPA 99 Health Care Facilities Code. [ROP 15-36]

517.19(B) Number of Receptacles in Critical Care Patient Bed Locations

The minimum number of receptacles required in a critical care patient bed location has increased from six to 14. These receptacles must be listed and identified as “hospital grade” and connected to an insulated copper equipment grounding conductor. This revision aligns with the new requirements in Section (B) of NFPA 99 Health Care Facilities Code. At least one of the 14 receptacles shall be connected to either the normal system branch circuit required in 517.19(A) or to a critical branch circuit supplied by a different transfer switch than the other receptacles at the same patient bed location. [ROP 15-39]

517.19(C) Operating Room Receptacles

New subdivision (C), Operating Room Receptacles, was added to 517.19, and the balance of the section was renumbered accordingly. The minimum number of receptacles required is increased from six to 36. The revision provides direction on which system branch the receptacles must be connected and that they be “hospital grade” type. NFPA 99 2012 Health Care Facilities Code has been revised by increasing the number of receptacles in patient care locations of healthcare facilities, including operating rooms. This revision aligns the NEC with Section of NFPA 99. [ROP 15-40]

590.4(J) Cable and Cord Supports

Cable assemblies and flexible cords and cables installed as branch circuits or feeders must not be installed on the floor or on the ground. Extension cords connected to receptacles and laid on the floor are considered suitable for this use because they “extend” the GFCI protection of the outlet. Construction locations are almost always wet locations. This revision aligns the NEC requirements with existing OSHA requirements and addresses a serious safety issue with feeders and branch circuits installed on the floor or laying on the ground on construction sites. [ROP 3-105; ROC 3-35] 

Chapter 6 Special Equipment

600.6(A)(1) Disconnect Required for Signs

Section 600.6(A)(1) is a significant worker safety issue requiring a sign disconnect to be located at the point where the circuit conductors enter the sign enclosure or pole. The revision provides the specific detail to restrict conductors on the line side of the disconnect switch from being routed into the enclosure to connect to a switch that is installed on the sign enclosure. If the disconnect is in the open or off position, live conductors are still present within the sign enclosure. This revision provides the needed clarification and prohibition. This safety-driven change simplifies worker compliance with both NFPA 70E and OSHA rules. [ROP 18-99; ROC 18-47]

625.41 Electric Vehicle Supply Equipment Circuit Ratings

Former 625.14 has been revised and relocated to 625.41 as a result of Article 625 being reorganized. A new last sentence that includes provisions for an automatic load management system has been added to 625.41. The maximum electric vehicle supply equipment load on a service and feeder shall be the maximum load permitted by the automatic load management system. This revision provides relief from service upgrades in some cases, but an automatic load management system has to limit the load on the service to its capacity. [ROP 12-52, 12-63; ROC 12-27a]

Article 646 Modular Data Centers

Article 646, Modular Data Centers, is new to NEC Chapter 6. This article includes four parts addressing general requirements, equipment, lighting and workspace. Modular data centers are prefabricated units of information technology equipment and support equipment. Modular data centers are intended for fixed installation either indoors or outdoors. This new article closely follows the arrangement and information contained in Article 645, Information Technology Equipment; and NFPA 75, Standard for the Protection of Information Technology Equipment. Some configurations use support equipment housed in a separate enclosure. [ROP 12-147; ROC 12-71, 12-74, 12-77, 12-80]

680.22(A)(2) Locking Receptacles and Attachment Plugs Not Required

List item (2), requiring a locking configuration, has been deleted. Removing this locking configuration from 680.22(A)(1) matches existing requirements of “Other Receptacles, Location” not less than 6 feet from a pool in 680.22(A)(2). Single receptacles of the grounding type and provided with GFCI protection for personnel are now considered sufficient safety measures for these locations. [ROP 17-101, 17-104, 17-105] 

680.42(B) Bonding for Outdoor Spas and Hot Tubs

This revision originated as Tentative Interim Amendment 1005 for the 2011 NEC. Based on four specific criteria, spas and hot tubs listed for outdoor use may be exempt from the perimeter surfaces equipotential bonding requirements of 680.26(B)(2). The class of spas referred to in this section is a self-contained outdoor/indoor-rated UL1563 listed product. [ROP 17-142, 17-144; ROC 17-46]

690.12 Rapid Shutdown of PV Systems on Buildings

Photovoltaic (PV) system circuits installed on or in buildings must now be provided with a rapid shutdown function that controls specific conductors in accordance with 690.12(A) through (D). Controlled conductors shall be limited to no more than 30V and 240 volt-amperes (VA) within 10 seconds of a rapid shutdown initiation. Where the need for an electrical safety product or system is demonstrated, prescriptive operational and safety requirements are incorporated in the NEC to stimulate the industry into meeting that need. Limiting firefighter exposure to electrical shock is an important safety requirement for first responders. Limited time to achieve a lower voltage level after shutdown is a system operational requirement. This new rapid shutdown requirement applies to PV systems or circuits installed on or in buildings. [ROP 4-253; ROC 4-108, 4-113]

690.31(G)(1) Marking for PV Circuits Embedded in Building Surfaces

Marking requirements of embedded PV circuits hidden within roofing material and other building surfaces have been strengthened. Hidden PV circuits must now be clearly marked using an approved method suitable for the weather and continuous exposure to sunlight. This requirement is necessary to protect personnel from hazards that could arise from accidental contact with PV conductors embedded in roofs. [ROP 4-204, 4-205]

694.1 Wind Electric Systems

The provisions of Article 694 apply to wind (turbine) electric systems that consist of one or more wind electric generators and covered by the NEC as determined in 90.2. The former size limitation of 100 kilowatts has been removed from the scope of this article. These systems can include generators, alternators, inverters and controllers. Wind electric systems can be interactive with other electrical power production sources or might be stand-alone systems. Wind electric systems can have alternating current (AC) or direct current (DC) output, with or without electrical energy storage, such as batteries. [ROP 4-345, 4-346]

695.4(B)(2)(2) Overcurrent Protection Selection

Past calculations sizing the disconnecting means and the overcurrent protective device included the sum of locked-rotor currents of all fire pump and jockey pump motors, plus the full-load current of the remaining loads. As revised, the calculations now include locked-rotor currents of only largest fire pump motor, plus the sum of other motor and remaining loads. The overcurrent protection must be by an assembly listed for fire pump service. Also, the overcurrent protective device shall not open within 2 minutes at 600 percent of the full-load current of the fire pump motor(s), it shall not open with a restart transient of 24 times the full-load current of the fire pump motor(s), it shall not open within 10 minutes at 300 percent of the full-load current of the fire pump motor(s), and the trip point for circuit breakers shall not be field-adjustable. This change aligns with the requirements in Section of NFPA 20, Standard for Stationary Fire Pumps. [ROP 13-57]

Chapter 7 Special Conditions

700.12(F)(2) Exception

The existing exception to 700.12(F)(2)(2) permitting unit equipment supplied by three or more normal circuits, no longer permits multiwire branch circuits to serve the uninterrupted area. Section 210.4(B) contains a general requirement to simultaneously disconnect all ungrounded conductors of multiwire branch circuits either with identified handle ties or by use of a common trip breaker. Using normal multiwire branch circuits increases the risk of an area being without emergency lighting if on of the circuits were to trip causing the others to be disconnected due to the handle tie arrangement.  Forbidding multiwire normal branch circuits in these specific instances provides additional safety during loss of normal lighting. [ROP 13-116]

700.19 Multiwire Branch Circuits Prohibited

A new 700.19 has been added addressing multiwire branch circuits used in emergency systems. This new provision prohibits multiwire branch circuits protected by common trip circuit breakers to serve emergency lighting and power circuits. Emergency lighting and power could be unavailable during ordinary line to ground faults and other problems where common trip circuit breakers or handle ties are employed. Continued reliability of emergency circuits requires this change. [ROP 13-118] 

700.28 Selective Coordination

The definition of the term selective coordination in Article 100 has been revised to clarify that the coordination is across the full range of available overcurrents. This change in 700.28 requires a professional engineer or other qualified person to choose the overcurrent protective device types, ampere ratings, and settings to achieve selective coordination. This responsible party must provide documentation to the authority having jurisdiction (AHJ) that the selection of the overcurrent protective devices achieves the required selective coordination. This process will ensure selective coordination for a project without an addition burden on the AHJ. Documentation is required to be made available to others involved in the original construction process, or post installation, to ensure the system is installed, maintained and modified with the knowledge of how the original system was selectively coordinated. The same revision has been incorporated into sections 620.62, 701.27 and 708.54 dealing with requirements for selective coordination of overcurrent devices. [ROP 13-126, ROC 13-85]

Article 728 Fire-Resistive Cable Systems

A new Article 728 titled “Fire-Restive Cable Systems” provides the necessary information required for the proper installation of fire-rated cables.  Precise installation requirements for fire-resistive cables are critical component of egress and safety during a fire. Many building and specific areas require the continued use of electrical energy during fire and other emergency conditions. This article contains specific requirements related to survivability of these fire resistive cable systems. As with many required products required in the NEC, fire resistive cables require proper installation to achieve their original purpose of providing electricity in a building during fire. As more fire resistive cables are installed, this article will play a prominent in these installations. [ROP 13-170, ROC 13-79, 13-80, 13-81, 13-83a, 13-83b]

760.24 Circuit Integrity (CI) Cable

A new 760.24(B) covers installation instructions for supporting circuit integrity (CI) fire alarm cable. Generally, CI cables must be supported at a distance not exceeding 24 inches by using only steel supports and fasteners. Circuit integrity cables installed within 7 feet of the floor must be fastened at intervals of not more than 18 inches. [ROP 3-178]

Article 750 Energy Management Systems

A new Article 750 titled "Energy Management Systems" defines and controls building systems while protecting the safety concerns of the NEC or building codes. With the application of the smart grid initiatives, premises energy management systems must be compatible with NEC and other personnel and building safety concerns. Article 750 provides a safe and systematic approach for load shedding and disconnection of power. Performance requirements in other energy codes should refer to the NEC for prescriptive electrical installation requirements. The most important aspect here is to ensure an overall energy management system does not override a system specific to addressing load shedding for an alternate power source for fire pumps and emergency systems. [ROP 13-180]

Chapter 8 Communications Systems

800.24 Mechanical Execution of Work

Nonmetallic cable ties or other nonmetallic accessories installed in other spaces used for environmental air are now required to be listed as having low smoke and heat release properties. This revision aligns the NEC with similar provisions contained in NFPA 90A. The same revisions have been incorporated into 770.24, 820.24 and 830.24. [ROP 16-17, ROC 16-100, 16-42, 16-166, 16-225]

800.179(G) Circuit Integrity (CI) Cable or Electrical Circuit Protective System

Requirements for CI cable or electrical circuit protective systems listing requirements have been added to 800.179(G). Listing information includes specific installation requirements in accordance with the listing to maintain minimum fire ratings. The new provisions clarify what constitutes a circuit protective systems and how circuit integrity cables must be part of a system installed to meet established fire resistive rating criteria. The same revisions have also been incorporated into Articles 725, 760 and 770.

Not all of the changes to the NEC are covered in this article. For complete details about these and other NEC revisions, refer to the NFPA 2014 NEC Report on Proposals and Report on Comments. The terms National Electrical Code and NEC are registered trademarks of the National Fire Protection Association.