The 2014 National Electrical Code (NEC) development process is in full swing with the NEC technical committees acting on 3,745 proposed new articles and revisions. New and improving technologies and industry advances are driving changes into the electrical industry at an accelerated pace. The requirements in the NEC must address the emerging technology to keep people and property protected from hazards that arise from the use of electricity.
Important factors—such as energy conservation, reduction of oil dependency and preservation of existing electrical infrastructures—are driving many changes. Future NECs will place significant emphasis on energy management and effective energy solutions. In the past, the NEC has typically been silent on energy management systems and techniques; they are often treated more as options. Energy management modifications to electrical systems in buildings can have an effect on safety; hence, the Code must be equipped. By including a new article covering basic safety requirements for energy management systems, the NEC is positioned to be the installation standard to which other energy codes (that contain performance criteria and requirements for energy management) can refer.
The NEC is also experiencing timely revisions in Article 625, which contains the rules for electric vehicle (EV) charging systems. Building a charging infrastructure for EVs will continue to progress incrementally. The proposed revisions proactively continue this cycle to address installation rules associated with current EV charging technologies.
Globally, proposed revisions in the Code include expanded and new rules for direct current (DC) systems and changing the previous 600-volt (V) threshold to a 1,000V maximum.
Now, let’s look at some proposed changes and new articles that have been accepted so far in the NEC 2014 development process.
110.17 Proposal No. 1-110
This proposed rule requires working space identification. The required working space to be kept clear needs to be readily identied on or adjacent to the equipment. The marking could be on the equipment, a wall or the floor.
110.21(B) Proposal No. 1-114
A proposed new subdivision (B) adds specific requirements for warning, caution or danger markings, labels, or signs required or specified elsewhere throughout the NEC.
The markings, signs or labels need to meet the requirements in ANSI Z535.4.
110.26(C)(2) Proposal 1-143a
This proposed revision reduces the ampere (A) value 1,200A to 800A. The proposed change clarifies the requirements for two entrances, and egress paths are required for large equipment with an 800A rating or greater.
210.12 Proposal No. 2-92
A proposed revision addresses arc-fault circuit interrupter (AFCI) requirements in dwelling units and recognizes the use of circuit breakers or outlet devices at the first outlet in the circuit. Four specific conditions must be met for outlet AFCI device installation.
210.17 Proposal 2-128a
The proposed change clarifies that outlet(s) installed for the purpose of charging EVs shall be supplied by a separate branch circuit. This circuit shall have no other outlets.
Table 250.102(C) Proposal 5-42
The proposed new table is used for minimum sizing of line-side bonding jumpers, grounded conductors, main bonding jumpers and system-bonding jumpers. References to this table have been inserted in appropriate sections.
310.15(B)(7) Proposal 6-49a
The proposed revision deletes the table and replaces it with a provision allowing a 0.83 reduction in ampacity for dwelling service and feeder conductors. The reduction is the same as permitted by former Table 310.15(B)(7) but presented in a user-friendly format. A new example is included in Annex D to describe how to apply the revised rule.
Article 393 (proposed as 302) Proposal 18-10a
A proposed new article, “Low Voltage Suspended Ceiling Power Distribution Systems,” addresses low-voltage DC equipment (lighting and power) connected to ceiling grids, floors and walls built for this purpose. This new article addresses equipment that has similar characteristics to track lighting but includes the wiring and power supply requirements.
400.7 and 400.8 Proposal 6-103
A proposed new list item (9) is added to Section 400.7 and recognizes that cords for accessory equipment associated with mechanical equipment are now permitted above a ceiling where not prohibited by 300.22.
450.10(A) Proposal 9-144
This proposed revision addresses grounding and bonding conductor connections in transformer enclosures. New subdivision (A) incorporates specific requirements for installing an equipment grounding terminal bar in transformer enclosures but not on the vent screen portion of the enclosure. The new requirement provides needed direction for installers on making grounding and bonding connections that provide an effective ground-fault current path. An exception addresses transformers with pigtail leads used as the connection means.
501.40, 502.40 and 506.21 and Exceptions
Proposals 14-59, 14-92 and 14-225a
These proposals delete these sections and their associated exceptions. The requirements for simultaneous disconnection of all ungrounded conductors of multiwire branch circuits are already provided in 210.4(B). As indicated in 90.3, chapters 1 through 4 apply generally to all installations unless modified or supplemented by the specific requirements in chapters 5, 6 or 7. This proposed revision removes the redundancy and results in an allowance for multiwire branch circuits in hazardous locations; however, all ungrounded conductors must be provided with a means of simultaneous disconnect as required in 210.4(B).
514.3(B)(1) Proposal 14-237
The proposed revision changes Note 2 following Table 514.3(B)(1) to now refer to Figures 514.3(A) and (B). The existing Figure 514.3 would be replaced with Figures 8.3.2(a) and 8.2.3(b) from NFPA 30A. The proposed revision results in consistency between NEC Article 514 and NFPA 30A. It incorporates these two useful figures that illustrating the current concepts and area classification for motor fuel dispensers installed remotely from the fuel storage tanks and for fuel dispensers installed on aboveground fuel storage tanks.
517.18(B) Proposal 15-36
Section 517.18 addresses general-care areas and in previous NEC editions applied to patient bed locations only. The first part of this proposed revision changes the word “location” to “room.” This proposed revision changes the location of the required minimum number of receptacles from being sited at the “bed location” to just being in the room. The second part of this proposed change increases the minimum number of receptacles required from four to eight. The proposed revision is from the NFPA 99 Technical Committee on Electrical Systems and is an effort to correlate between NEC Article 517 and the revised requirements contained in NFPA 99 2012.
517.19(B) Proposal 15-39
Section 517.19 addresses critical-care patient bed locations. This proposed revision in subdivision (B) changes the required minimum number of receptacles from six to 14. The receptacles required by this section are still required to be listed as “hospital grade.” The proposed increase in number of receptacles is related to the increased quantities of medical appliances and electrical equipment essential for patient care. List item (2) in this section was revised by removing the term “emergency system” and replacing it with “critical branch.” The proposed revision is from the NFPA 99 Technical Committee on Electrical Systems and is an effort to correlate between NEC Article 517 and the revised requirements contained in NFPA 99 2012.
517.19(C) Proposal 15-41
Code-Making Panel (CMP) 15 reacted favorably to the proposal to include a new subdivision (C) in 517.19. This new subdivision, “Operating Room Receptacles,” includes requirements for minimum quantities to be provided and to which branch of the essential electrical system they must be connected. The minimum number of receptacles required in an operating room is 36. At least 12 of the 36 receptacles must be connected to either the normal system branch or the critical system branch. Consistent with 517.18(B) and 517.19(B), all of the receptacles required for operating rooms must be listed as “hospital grade.” The grounding terminal of these receptacles must be connected to the reference grounding point by means of an insulated copper equipment grounding conductor.
517.30(F) Proposal 15-66 (Rejected)
A proposed new subdivision (F) has been added to this section: “Selective Coordination.” It provides specific operating criteria for overcurrent device selective coordination in the essential electrical system. As proposed, the overcurrent devices for the essential electrical system no longer have to be fully selective but are required only to be selectively coordinated for fault events that exceed 0.1 seconds. NFPA 99 contains performance requirements that must correlate with the installation requirements in Article 517 of the NEC. While the NEC definition of “selective coordination” indicates full coordination without mention of time duration of fault events, the new proposed language modifies that general criteria contained in the definition.
Article 625 Proposal 12-52
The proposed revision changes the article title to “Electric Vehicle Charging and Supply Equipment Systems.” It has been renumbered and reorganized to provide a logical sequence and arrangement. The most notable changes proposed are revised and new definitions in 625.2, clarification of cord-and-plug connected supply equipment in 625.44, and the allowance of automatic load management systems to ensure service or source capacities are not exceeded as proposed in 625.12. Other revisions are specific criteria for cords and cables in 625.17 and marking requirements in 625.30 for individual branch circuits installed for supplying EV supply equipment.
645.27 Proposal 12-143
This proposed new section, “Selective Coordination,” requires that all overcurrent devices in critical operations data systems be selectively coordinated with all supply-side overcurrent devices. Information provided in the substantiation emphasized the importance of power reliability and continuity of service for reasons of public safety, emergency management, national security and business continuity.
Article 646 Proposal 12-147
This proposed new article is titled “Mobile Data Centers.” Proposed Section 646.2 defines the term “mobile data center” to differentiate between data centers that currently fall under the scope of Article 645. As indicated in the substantiation, mobile data centers can vary in physical characteristics from a large enclosure to a prefabricated building. The contained equipment in the enclosures or prefabricated buildings would be fully customizable and scalable to provide data center operations but typically would not be permanently installed. Key provisions include nameplate information, minimum size for supply conductors, overcurrent protection sizes, wiring methods and HVAC system requirements.
690.12 Proposal 4-253
A new Section 690.12, “Arrays on Building Response to Emergency Shutdowns,” has been proposed in Part II of Article 690. It would apply to photovoltaic (PV) systems installed on building roofs and would require that PV source circuits be de-energized from all sources within 10 seconds of when the utility supply is de-energized or when the PV power source disconnecting means is opened. When the source circuits are de-energized, the maximum voltage at the module and module conductors would be limited to 80V.
700.19 Proposal 13-118
This proposed new section, “Multiwire Branch Circuits,” restricts branch circuits for emergency power or lighting from being part of a multiwire branch circuit. This proposal is an effort to reduce the possibility of loss of power to one or more emergency circuit due to the simultaneous disconnecting means provisions contained in 210.4(B). The problem is that, if one of the emergency circuits were to trip, it could disconnect the other ungrounded conductors of the same multiwire branch circuit because the circuit is supplied by either a multipole breaker or single-pole breakers under a common identified handle tie.
Article 750 Proposal 13-180
This proposed new article, “Energy Management Systems,” includes definitions, requirements for alternative-power sources, load-management provisions and field-marking requirements. Energy codes typically include performance requirements for managing and conserving energy in buildings or structures. The NEC contains installation requirements that must be applied to such energy management systems and installations. This new article provides a good basis for inclusion of general requirements to address the types of loads permitted to be controlled through energy management.
This article provides only a high level summary of significant changes proposed for the 2014 NEC. The proposed changes in this article are not final and are subject to public review and comment. The 2013 NEC Report on Proposals provides more details. NFPA encourages participation in this process though submittal of comments to these proposed changes. Comment forms can be obtained at www.nfpa.org.
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.