John,
I am talking about landing a wire without connections directly to a copper ground bar. I was reminded by an AHJ that we should not allow AL wires to be landed on copper ground bars. For example Ilsko D-176 web site here:
http://ilsco.com//TechnicalDrawing//N0009.pdf States that it is UL listed for CU wire only.
YET, when inspecting a Generac transfer switch the EC on the job I was going to red sticker the job. The EC on the job asked me to read a small label in the top left corner of the switch. He had to move the wires out of the way so that I could read it. It stated that all of the connections in this transfer switch was UL listed/labeled for CU or AL wires.
Now that seems to go against the manufacture of the ground bar listing. Should you pass it (and accept the UL listing of the switch) or fail the job (Because AL wires on copper ground bar is not allowed by UL listing)?
The only label to follow is the one supplied by the manufacturer of the final UL Listed device.
A general statement like 'never land AL on CU' does not apply when UL has done the actual testing.
A reference to general use instructions for a similar looking ground bar are meaningless. First, the switch's bar may be a different manufacturer. Second, the Ilsco device is actually Component Recognized by UL, which means it must be used as 'part of' something larger assembly. Third the Ilsco ground bar does not really say copper only, it has the stamp 6-14CU in one location, and 4-14 (no material type listed) in another.
