Key Changes in the 2014 NEC Code
Posted in: July 2014
Every three years the National Electrical Code® is revised and new standards are published. Suggestions for these changes come primarily from professional electrical contractors like you and reflect the changing way we use electricity, new products, and emerging technologies.
Among the more significant revisions in the 2014 NEC® Code are a change from 600- to 1,000-volt thresholds throughout as a result of the increasing adoption of wind and solar power generation. The 2014 Code also incorporates requirements for direct current (DC) systems and wiring throughout.
Other major changes are discussed below. The actual code change is in italics, with deleted sections indicated as strikethroughs, followed by an analysis of the changes.
Wiring Methods and Materials - Other Places Used for Environmental Air (Plenum)
Nonmetallic cable ties and other nonmetallic cable accessories used to secure and support cables shall be listed as having low smoke and heat release properties.
This new requirement was added to the end of Section 300.22(C)(1) and requires nonmetallic cable ties and other nonmetallic cable accessories to be specifically “listed” for installation in other spaces used for environmental air.
Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings; and Handholes – Smaller Dimensions
Listed boxes or listed conduit bodies of dimensions less than those required in 314.28(A)(1) and (A)(2) shall be permitted for installations of combinations of conductors that are less than the maximum conduit or tubing fill (of conduits or tubing being used) permitted by Table 1 of Chapter 9.
Listed conduit bodies of dimensions less than those required in 314.28(A)(2) having a radius of the curve to the centerline not less than as indicated in Table 2, Chapter 9 for one shot and full shoe benders, shall be permitted for installations of combinations of conductors permitted by Table 1 of Chapter 9. These conduit bodies shall be marked to show they have been specifically evaluated in accordance with this provision.
Where the permitted combinations of conductors for which the box or conduit body has been listed are less than the maximum conduit or tubing fill permitted by Table 1 of Chapter 9, the box or conduit body shall be permanently marked with the maximum number and maximum size of conductors permitted.
This section was revised to eliminate the specific conductor marking requirements for listed conduit bodies of smaller dimensions having a radius of the curve to the centerline not less than as indicated in Table 2, Chapter 9. This is the same minimum radius of curve required for field bends in IMC, RMC, and EMT found in Sections 342.24, 344.24, and 358.24 respectively. Therefore, these are suitable for installations of combinations of conductors of the maximum conduit or tubing wire fill (of conduit or tubing being used) permitted by Table 1 in Chapter 9.
These designs greatly simplify wire fill calculations for conduit bodies for both design and inspection and do not require conductor size markings. The 2011 NEC® text in Section 314.28 (A) (3) was restrictive for these designs as it technically did not permit installation of the full Table 1, Chapter 9 wire fill for the conduit or tubing being used. These conduit body designs effectively negate the concern for wire jamming addressed in Informational Note No. 2 to Tables in Chapter 9.
Liquidtight Flexible Nonmetallic Conduit: Type LFNC - Uses Not Permitted
LFNC shall not be used as follows:
(1) Where subject to physical damage
(2) Where any combination of ambient and conductor temperatures is in excess of that for which the LFNC is approved
(3) In lengths longer than 1.8m (6 ft.), except as permitted by 356.10(5) or where a longer length is approved as essential for a required degree of flexibility
(4) Where the operating voltage of the contained conductors is in excess of 600 volts, nominal, except as permitted in 600.32(A) (5) (4) In any hazardous (classified) location, except as permitted by other articles in this Code
The restriction that limited LFNC to 600 volts was removed from the 2014 NEC. LFNC is listed and has been evaluated to meet or exceed the very rigorous physical requirements such as impacts and crush per UL1660, Liquid-Tight Flexible Nonmetallic Conduit. In addition, UL Certification Guide Information, DXOQ, did not limit LFNC to 600 volts.
Receptacles, Cord Connectors, and Attachment Plugs (CAPS) - Receptacles of 15 and 20 Ampere in a Wet Location (Also covered in: Section 314.15 Damp or Wet Locations)
Receptacles of 15 and 20 ampere installed in a wet location shall have an enclosure that is weatherproof whether or not the attachment plug cap is inserted.
For other than one- or two-family dwellings, An outlet box hood installed for this purpose shall be listed, and where installed on an enclosure supported from grade as described in 314.23(B) or as described in 314.23(F) and shall be identified as “extra-duty.” All 15- and 20- ampere, 125-and 250-volt nonlocking-type receptacles shall be listed weather-resistant type.
406.9(B)(1) was revised for the 2014 NEC® to require a Listed “Extra-Duty” While-In Use weatherproof cover to be used for all 15- and 20-ampere receptacles when located within an area defined as a Wet Location.
Electric Vehicle Charging Systems
Article 625 was re-written and re-organized. As noted by the numerous comments cited above, there were many modifications to the entire article. There were additional revisions such as “fastened in place” that was held for further study by the code making panel (comment 12-25).
The reorganization was designed to make the article more user-friendly. The titles for the various parts of Article 625 did not fit the requirements found within those parts and were revised in order to enhance the understanding of this article. Article 625 had installation requirements scattered throughout the article. This revision was intended to better organize the article.
Wind Electric Systems
The provisions of this article apply to wind (turbine) electric systems that consist of one or more wind electric generators. These systems can include generators, alternators, inverters, and controllers.
The article scope was revised to eliminate the restriction to “small” systems. The scope and remaining sections of the article had a system limitation to 100kW. NEC® requirements are needed for all wind electric systems and this article now applies to systems both higher and lower than 100kW.
Fire-Resistive Cable Systems
This article covers the installation of fire-resistive cables, fire-resistive conductors, and other system components used for survivability of critical circuits to ensure continued operation during a specified time under fire conditions as required in this Code.
This is a new article for the 2014 NEC® to cover the installation requirements for Fire-Resistive Cables. A Fire-Resistive Cable System is the combination of a cable and associated components such as boxes, fittings, raceways, cable tray, and mounting means to be used together to ensure the survivability of critical circuits for a specified amount of time under fire conditions.
Energy Management Systems
This article applies to the installation and operation of energy management systems.
This is a new article for the 2014 NEC® to cover the installation requirements for Energy Management Systems. Energy Management Systems consist of monitor(s), communication equipment, controller(s), timer(s), or other device(s) that enable the surveillance and/or control of an electrical load or a power production or storage source.
For a more in-depth analysis of the new NEC code, the Thomas & Betts publication, Analysis of NEC® Code Changes 2014, is available free at www.public.tnb.com/pub/en/node/1890. Those interested in a printed copy may ask their T&B sales representative.
David Kendall is Director–Industry Affairs for IEC National Platinum Partner Thomas & Betts Corporation, a member of the ABB Group. He is a participating technical committee member for the National Electrical Code on Code Making Panel 8 and represents Thomas & Betts and the Vinyl Institute on the National Electrical Code. Kendall develops educational presentations, publications, and training for Thomas & Betts products in conjunction with the electrical contractors and electrical inspectors. His responsibility includes technical sales support and training, including interpretation of the NEC®, to all regional sales managers, sales representatives, distributors, OEM’s, and end users.