Class 1 Division 2 Repair garage

[scottam99]

I will be contacting the AHJ regarding this question. I have a panel that is 72" high. in order to have it outside the 30" boundary The top breakers would exceed the 6'7" maximum height for installation. My question is this. Is the boundary based on the height of the back box or is it based on where the lowest breaker would be? If the back box was mounted at 27-1/2" I would be within the 6'7" height restriction. The main breaker would be at 38" above finished floor which is where I would assume any arching could ocurr. Any thoughts?

 

[rbalex]

First, let's talk about the '30" boundary'. Where did that come from? In general, with no ventilation, the classified location envelope is 18" above the floor.

 

[don_resqcapt19]

It would be my opinion that 511.7(B)(1)(a) would prohibit the enclosure from being in the classified area.
What is the code reference for the 30" boundary?

 

[scottam99]

The 30" boundary was quoted to me by the AHJ. The blue prints state per electrical engineer use wiring methods per article 511 in shop area

 

[rbalex]

The "boundary", if any, is 18" above the floor. See Sections 511.3(C)(1) and 511.3(D)(1).