Use of Frame as EGC NEC17

[00crashtest]

In the 2017 edition of the National Electric Code, on page 125, 250.136(A), titled Equipment Secured to Grounded Metal Supports, says, "The structural metal frame of a building shall not be used as the required equipment grounding conductor for ac equipment." Since it makes no mention of dc, does this mean that DC equipment is always allowed, unless there are other restrictions, to use buulding frames as the required EGC? In general, if the authority having jurisdiction hasn't made additional relevant restrictions, does the NEC work like common law, where such thing is not explicitly prohibited (in any direct or indirect way) is always allowed? Or does it instead work like civil law where such thing is not explicitly allowed is always prohibited?

 

[jaggedben]

DC equipment requiring an EGC would still need an EGC listed in 250.118. So your question is pretty moot in this case. But in general, things not prohibited by the NEC are allowed. (I don't think your characterization if civil law is correct, btw.)

 

[00crashtest]

DC equipment requiring an EGC would still need an EGC listed in 250.118.

Then the restriction in 250.136(A) is also moot, as it is already effectively prohibited in 250.118.

 

[00crashtest]

But in general, things not prohibited by the NEC are allowed.

Thanks for confirming my intuition, because the sovereign nation of the NEC that it's based in operates on the principle of common law.