I have a 600 amp 3 ph 4 wire 480 volt I-Line panel with a main breaker being fed from utiliy power 2 runs of 350 mcm copper. out of the I-line it feeds a 75 kva 480/120/208 3 ph 4 wire transformer for a lighting panel in the same room as the I-line, 480 side is in pvc with # 2 copper secondary side is pvc with 3/0 copper, bonding to be done in transformer. Also out of the I-line we are feeding a 6' hoffman enclosure used as a motor control panel, within the hoffman is a 400 amp 3 ph breaker used as a main for all motor starters,they are all individually fused within the box, also pvc from the I-line with 500 mcm no neutral. Then last a 5kva transformer 1ph 480/120/240 being used for 120v control power on one leg and computer power on the other leg. This transformer is on the outside of the hoffman box with metal sealtight, being fed off the 400 this is so that when the hoffman is locked out, the control and computer are also dead. please help with grounding and bonding.

Last edited by lite bulb; 11/18/14 12:04 AM.