January 2011 Electrical Apparatus

January 2011 Electrical Apparatus

This is a summary of the Electrical Apparatus January 2011 featured technical article,  by Richard L. Nailen, P.E.     

The NEC is the minimum safety standard for electrical installations. It’s written to facilitate legal enforcement if adopted by state and local jurisdictions. Published as Standard 70 by the National Fire Protection Association, the Code is revised every three years, and the 52nd (2011) edition has just been issued. The 870-page volume contains 145 separate Articles. We can highlight only a few of the more significant revisions.

First is the addition of three new Articles. No. 399 is titled “Outdoor, Overhead Conductors, Over 600 Volts.”

A second new Article in the 2011 NEC is No. 694, “Small Wind Electric Systems.” The third new Article is No. 840, “Premises-Powered Broadband Communications Systems.”

A fourth new Article was proposed: No. 862, “Optical Fiber Communication Raceways.” CMP-16 rejected the proposal. Also rejected was a new Article 393, “Non-Continuous Cable Supports.” A new Article 606, which would have dealt with “Prefabricated Wiring Assemblies,” was also turned down

NEC language must meet two criteria (not always successfully). One is that a requirement be clear and unambiguous. A second is that technical terms must be clearly defined. The Style Manual lists terms and dictates their use. A “Glossary of Terms Technical Advisory Committee” oversees the content of NEC Article 100 (Definitions).

Several surprises in the Code are outlined in our January 2011 issue. For example, Article 100 has contained no definition for one of the most troublesome electrical hazards: the ground fault. And, in Article 500 dealing with hazardous areas, the NEC has for many years listed numerous requirements for installations in dusty environments—but the Code has never defined “combustible dust.” Other NFPA standards offer definitions that are not quite consistent or highly subjective.

Read our January issue for more of the NEC’s content, including: What constitutes “high voltage”? What’s a “conduit”? UPS (Uninterruptible Power Supply)? Many other aspects of the code’s new changes are also discussed.

To order a back issue with the full article, “It’s that time again – The 2011 National Electrical Code,” call 312-321-9440 or visit our online webstore.

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