Stainless Steel screw for bonding

[69gp]

Hi I posted this in the solar and did not get an answer. Maybe someone here can provide an answer. Where in the 2017 NEC can I find that the screw for a pressure connector located outside in the elements needs to be Stainless Steel.

thanks

 

[hbiss]

Nowhere. That would be up to the manufacturer of the connector.

Just so you know, we read all the forums so posting the same question in two different forums isn't going to help you.

-Hal

 

[jaggedben]

There is probably something general in the NEC that states that electrical connections must be suitable for the environment. Maybe in article 110. If not, I'm pretty sure that there's something in 250 about grounding connections being listed for grounding, so that probably would cover it too.

I can tell you that it's well known throughout the solar industry that grounding parts on arrays need to be listed for solar arrays (UL 2703) or for direct burial which in practice means either stainless steel with tinned copper, or bronze.

 

[electrofelon]

Its a bit of a pet peeve of mine, but I hate the solar industry's obsession with stainless steel. It is often mated to aluminum which is a horrible combination in the galvanic series and should be avoided. Granted those direct bury rated lugs are typically tin plated copper with stainless screw which is a better combination, but you see stainless hardware against aluminum many other places.

 

[kwired]

I think this is a listing issue and not a code issue. Only code that would apply would be 110.3(B), which tells you apply listing and instructions included in the listing.

Only thing in NEC I am aware of that includes "listed for grounding" applies to connecting devices used on grounding electrode conductors.