Code regarding metal vs plastic switch/receptacle covers?

[5mall5nail5]

Hi all -

A colleague who knows I am working on my own garage and looking at NEC stuff just asked me if I knew of any code that would require metal vs plastic wall switch and receptacle plates. He noticed his whole house is plastic plates yet his garage is all metal plates. Any thoughts?

Thanks,
Jon

 

[Stuart in MN]

It's possible there are local regulations, but there are no national code issues as far as I know - you just need a cover plate, the code doesn't specify the material.

 

[Higgins]

It could be the case where the electrical boxes in the garage were surface mounted which requires a metal cover.

AL

 

[Stuart in MN]

There may be local restrictions, there's nothing in the NEC that requires metal covers on surface mount boxes.

 

[billp603]

If it is an attached garage the metal plates may be required to meet the fire resistance of the wall if it's common to the living area. In my garage the only metal plate is the switch plate by the entry door to the house. The house was built 15 years before we moved in and I always assumed that was why. Could just be a coincidence.

 

[Charles (in GA)]

NEC 406.5(B) requires that SWITCHES installed in new work, or as replacement anywhere there is a equipment grounding conductor, that switch must have a ground wire screw/connection on it and it must be capable of grounding the switch cover, even if the switch cover that is installed is non-conductive.

Older type switches do not have a terminal to attach a ground wire, and are no longer allowed to be used, except where there is no ground conductor present in the box (older houses with two wire systems), and then only if the cover is non-conductive in most circumstances.

NEC 314.25(A) requires that if metal covers are installed that they must be grounded as specified by NEC 250.110.

Charles