Part 1 of this series covered the most significant National Electrical Code (NEC) revisions in Article 90, Chapter 1. Part 2 addressed Chapter 2. Part 3 dealt with Chapter 3. Part 4 covered some of the more significant revisions in NEC chapters 4 and 5. Part 5 addresses some of the changes in Chapter 6 through 8. Chapter 6 covers special equipment, Chapter 7 covers special conditions, and Chapter 8 covers communications systems.
Chapter 6 Special Equipment
Section 600.6 Disconnects (Revision)
This revision clarifies that the disconnecting means for electric signs and outline lighting systems must supply only those loads, and they are not permitted to supply any other load. The previous language of this section did not clearly indicate that the disconnecting means was limited to the sign or outline equipment supplied. This revision provides that clarification.
Another clarification this revision provides is the inclusion of skeleton-tubing installations. It was generally understood that this section applied to skeleton-tubing systems, but the requirement did not previously address it. The revision clarifies that the required disconnect for each feeder or branch circuit supplying a sign or outline lighting system is not permitted to supply another load.
Section 600.7(B)(1) Exception (New)
The new exception to 600.7(B)(1) relaxes the requirements for bonding metal parts of equipment supplied by Class 2 circuits. This section provides correlation with the provisions of 250.112(G) that generally require all metal parts of signs and outline lighting systems to be bonded to the equipment-grounding conductor of the supply circuit. Previously, it did not matter what the sign or outline lighting system voltage was. All metal parts had to be grounded and bonded. This new exception recognizes the limits of low-voltage systems supplying signs and outline systems. The new exception applies only to the remote metal parts associated with this type of equipment (i.e., the parts that are exposed only to the low-voltage circuit supplied by the Class 2 transformer or power supply).
Section 625.2 Plug-in Hybrid Electric Vehicle (PHEV) (New)
A new definition of the term “plug-in hybrid electric vehicle” (PHEV) has been added to 625.2, and a new sentence has been added to the current definition of electric vehicle, as follows: “Plug-in hybrid electric vehicles (PHEV) are considered electric vehicles.” This revision identifies plug-in hybrid electric vehicle supply equipment as an alternative and equivalent type of supply equipment for premises-wiring systems. This new definition is included in 625.2 and referenced in the scope of Article 625, to clarify that these types of vehicles are covered by the rules in this article. This definition indicates that not only does a PHEV include an onboard source of motive power, but the power-storage capabilities can also be used as an alternative power source to supply wiring systems. These vehicles include a recharging system for the onboard battery-storage units. A new definition of the term “rechargeable energy storage system” has also been added to 625.2
Section 630.13 Disconnecting Means (Revision)
The word “identified” has been inserted before the term “disconnecting means” in 630.13. The identification requirement will assist personnel in identifying the appropriate means to disconnect supply power to an individual welder that may be located among a group of welders.
Section 645.4 Special Requirements for Information Technology Rooms (Revision)
This section has been revised to improve clarity and usability. The existing informational notes have been revised to reflect the current edition of the National Fire Protection Association (NFPA) 75 and the applicable sections where appropriate. Additionally, a new list item (6) and an associated informational note have been added to this section. The new list item (6) clarifies that only equipment and wiring related to the operation of the information technology room is allowed to be installed within that room.
Section 645.10 Disconnecting Means (Revision)
Section 645.10 has been expanded and restructured into two subdivisions, covering remote disconnecting means controls and critical operations data systems. A new final sentence has been added that provides direction for users about disconnecting means for critical operations data systems. This section now includes conditions under which remote disconnecting means controls may be eliminated in critical data systems. The concerns are for critical data system loss and disruption. Five specific conditions must be met before the provisions in (B) can be applied and the remote disconnecting means control can be eliminated.
Section 670.5 Short-Circuit Current Rating (New)
Section 670.5, Short-Circuit Current Rating, has been added to Article 670. This new requirement correlates with the general rule in 110.9, covering equipment to be applied on systems that do not exceed the amount of available fault-current ratings of such equipment. This equipment is required to be marked with the short-circuit current rating.
Section 680.23(A)(8) Compliance (Revision)
This revision removes the 15-volt threshold for underwater luminaires and replaces it with reference to the low-voltage contact limit that is newly defined in 680.2. As long as the low-voltage contact limits (as defined and provided in the new definition) are not exceeded, ground-fault circuit interrupter protection is not required. These voltage sources are produced by specific transformers or power supplies manufactured for use with specific luminaires that are equipped with light-emitting diode technologies. This equipment is required to be listed for this use.
Section 680.74 Bonding (Revision)
This revision requires that the 8 AWG copper-bonding conductor be long enough to terminate on a replacement nondouble-insulated pump motor in the hydromassage bath tub. This bonding conductor is required to be connected to the pump motor branch circuit’s equipment-grounding conductor if a double-insulated circulating pump motor is installed. This revision requires the equipotential-bonding conductor to be routed to a hydromassage tub motor location, even if it is a double-insulated type. The idea is to be proactive in case of a replacement motor being one of the standard types that is not double-insulated and thus requiring a bonding connection that might otherwise get left unbounded to the installed equipotential-bonding system.
Section 690.4 Installation (New)
This new requirement in 690.4 mandates that only qualified people install photovoltaic (PV) systems, including all wiring and equipment. Similar new requirements are also included in Article 692 (Fuel Cells), Article 694 (Small Wind Electric Systems) and Article 705 covering interconnected electrical power production sources. These systems are often operated in parallel with the serving utility provider and require specific knowledge of paralleling equipment, transfer equipment and interactive inverters to avoid possible back-feed into the utility source.
Section 690.4(F) Circuit Routing (New)
This new requirement also mandates that, where PV module systems are integrated into the roof and the associated circuits are imbedded in the roof, the location of these circuits must be clearly marked. This would require a physical marking on the rooftop to warn firefighters and workers of the circuits contained in the roof. While no prescriptive means for applying this marking is included in the new requirement, this marking should be permanent and easily seen in any weather condition.
Section 690.31(E)(1) Beneath Roofs (New)
Direct current (DC) photovoltaic (PV) source and output raceways and MC cable are now prohibited from being installed within 10 inches of the roof decking or sheathing except where directly below the roof surface covered by PV modules and associated equipment. Additionally, where circuits penetrate the roof, they must be run perpendicular to the roof penetration point to supports a minimum of 10 inches below the roof. The goal is to not embed circuits within concealed building construction because others may need to penetrate the roof after installation. Also, in the event of an emergency, responders would be vulnerable to electric shock because these circuits are still energized and concealed, so they must now be clearly marked as required by Section 690.4(F).
Chapter 7 Special Conditions
Section 700.10(D)(1) Feeder Circuit Wiring (Revision)
The minimum fire rating in 700.10(D)(3), (D)(3) and (D)(4) has been increased to a 2-hour fire rating. The requirement for the fire rating of spaces containing equipment in 700.10(D)(2) is also increased to a 2-hour rating allowing for safe egress from buildings within established time frames that are consistent for emergency systems in conformance with other safety standards, such as the Life Safety Code. The 2-hour requirement can be achieved using suitable wiring methods (such as MI cable or MC cables) installed to meet specific installation criteria or by encapsulating the emergency feeder circuit(s) within building construction that is installed to achieve a 2-hour fire rating.
Section 701.6(D) Ground Fault Indication (New)
Section 701.6 has been expanded to require audible and visible signal devices be installed to indicate a ground fault in solidly grounded wye legally required standby systems of more than 150 volts-to-ground and circuit-protective devices rated 1,000 amperes or more. The new provision aligns Article 701 with Article 700, which includes the same requirements. A legally required system must provide power to loads classified as required, such as police stations, 911 centers, etc. Although 700.26 indicates that ground-fault protection of equipment is not required on the alternate source for legally required standby systems, ground faults can occur and can result in an equipment burndown. Because of the emergency nature of such systems, automatic disconnect in the event of a ground fault is inappropriate. Detection of such a fault, however, is desirable so that the condition can be corrected.
Sections 760.41(B) and 760.121(B) Branch Circuits (Revision)
The location of the overcurrent protective device (OCPD) for the branch circuit supplying the fire alarm equipment must be identified at the fire alarm equipment. The OCPD must be identified using the color red, be accessible only to qualified personnel and marked to identify it as supplying the fire alarm system. This marking requirement will raise the level of awareness for building owners, maintainers and service personnel about the need for continuity of power circuits that supply fire alarm systems. Even though fire alarm equipment must be provided with a backup system (often batteries), the backup power storage can be drained if the normal power is interrupted for long periods of time. The new marking requirement should draw more attention to circuits that must not be disconnected other than in extenuating circumstances and should be restored as quickly as possible. Many of these circuits are also provided with a lock-on device that is available as an accessory feature from circuit breaker manufacturers.
Chapter 8 Communications Systems
Article 800 and Chapter 8 Articles (Global Revisions)
Throughout Chapter 8, the term “grounding conductor” has been replaced with a new proper term. The new informational and associated figures explain the use of the terms “bonding conductor” and “grounding-electrode conductor” within Article 800 and the other articles in NEC Chapter 8. Two new diagrams clearly illustrate how these terms are applied in Article 800.
Article 840 Premises-Powered Broadband Communications Systems (New)
A new Article 840 has been added to Chapter 8 to address installations of optical fiber-based communications systems that are powered, not by the service provider, but from the premises served. These systems may supply a full range of voice, video, data and interactive services through an optical network terminal.
This article concludes the series on 2011 NEC changes. For more detailed information about these or any other important NEC changes, refer to the textbook, “2011 NEC Significant Changes,” published by the National Joint Apprenticeship and Training Committee, or view the archives of this series on ecmag.com. Additional detailed information about each proposal and comment resulting in NEC changes is provided in the NFPA Report on Proposals and Report on Comments for the 2011 NEC. It is also highly recommended that a copy of the 2011 NEC be referred to for complete information about the rules that have been added or revised in this edition.
The 2014 NEC development process has already begun and many proposals have already been submitted. You can do your part by submitting a Code change proposal where you believe there is a need for a revision or improvement in the NEC. It results in a dynamic Code that is continuously developed under the open-consensus process.
JOHNSTON is NECA’s executive director of standards and safety. He is former director of education, codes and standards for IAEI; a member of the IBEW; and an active member of the NFPA Electrical Section, Education Section and the UL Electrical Council. Reach him at firstname.lastname@example.org.