I am working on an installation where I am running wire between relays located in two 3' x 4' cans. The cans are connected by four 3" nipples. The design load on the wiring between the cans is 750 amps.
When sizing the wire, normally I would use the ampacity tables for 3 conductors in a raceway, but I was wondering if I can use the tables for wire in free air? Is the nipple between the cans considered a raceway? I talked to the customer about this and he indicated that their UL listed inverters use free air ampacities for the interior wiring, so he thought it would be OK for me to do the same.
Any insight/opinions/comments would be greatly appreciated.
Thanks
When sizing the wire, normally I would use the ampacity tables for 3 conductors in a raceway, but I was wondering if I can use the tables for wire in free air? Is the nipple between the cans considered a raceway? I talked to the customer about this and he indicated that their UL listed inverters use free air ampacities for the interior wiring, so he thought it would be OK for me to do the same.
Any insight/opinions/comments would be greatly appreciated.
Thanks