Base plate grounding

[BAHTAH]

Installed (2) 100/3 Sq-d contactors in an enclosure with a plywood backboard. Each contactor had a ground symbol and threaded hole on the baseplate for grounding. I am not sure what size the threaded hole was, but it was smaller than a standard 10-32 ground screw. The enclosure is grounded via the conduits. My question is, what size conductor would be used to bond the contactors to the enclosure? And why are manufactures providing threaded grounding points that are smaller than 10-32. I am not sure I could buy a ground screw (green) to match what is provided.

 

[iwire]

Installed (2) 100/3 Sq-d contactors in an enclosure with a plywood backboard.

First, why the heck is there plywood involved? :-?

Next time buy an enclosure with a back plane.

My question is, what size conductor would be used to bond the contactors to the enclosure?

What size breaker is supplying the contactors? If it's a 100 amp 250.122 requires 8 AWG.

And why are manufactures providing threaded grounding points that are smaller than 10-32.

There is no code requiring them to use 10-32.

I am not sure I could buy a ground screw (green) to match what is provided.

There is no reason you have to use a green screw, use a standard machine screw. I believe that hole is 8-32 if I remember right.

Personally I would rip the carpenters material out of the electricians box and find a way to use metal. For example install shallow uni-strut in the box and mount the contactors to that.