National Electrical Installation Standards

Standards as High as Your Own

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Thursday, May 31, 2018

Question:

I'm currently a student in the F.E.A.T. school in Florida and I notice there are a ton of mentions to "subject to physical damage" or "severe physical damage". I have asked my teachers and my boss if it's defined anywhere what physical damage covers. The only answer I've gotten that makes sense is thru my boss stating that the determination of what physical damage is, is left to the AHJ that runs the area. My question is just if there is a detention anywhere for what all is subject to physical damage or is it like my boss stated it is just up to the AHJ? I was curious is there was another book that might state it or not. Thank you for your time and hopefully hear from you soon

Devon Prest

A

Answer:

Hey Devon thanks for your question and congratulations on getting an education to become an electrician. There are several rules about physical damage protection in 300.4 and the wiring methods themselves have additional rules. As example, Electrical Metallic Tubing is not allowed where subject to severe physical damage as stated in 358.12(1) but there is no similar restriction for Rigid Metal conduit in Article 344. If damage to the contained conductors is likely, that is often considered a situation that is exposed to severe physical damage, such as areas with vehicle traffic. Neither term is defined in the NEC so your boss is essentially correct, other than the part about "running the area", the final approval decision is up to the AHJ as stated in 110.2.

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