james blake
Member
- Location
- Colorado
A co-worker and I were wiring a 150 KVA transformer with a 480V primary and a 208Y120V secondary, in the basement of a school. We were feeding a 400A panel. Our secondary ungrounded conductors were two parallel runs of 4/0 cu THHN. I told my co-worker I would pick up the 1/0 cu THHN (based on the largest ungrounded conductor) to run to our water pipe electrode. He told me that there is no way he is going to run 1/0 when we only need to run a 6 awg to the water pipe. He referenced 266.66(A). I explained to him that 250.66(A) applied to ground rods and driven pipe electrodes, not water pipe. He would have none of that. He said he had been doing it like that for years and that even an inspector said he was right. I've been working in the electrical trade for eleven years, and my co-worker has been in it for at least twenty or more. Does he know something I don't?