In a 4 unit building. The meter bay has 7o amp breakers from each meter that supplies a 60 amp breakers via #2 alum. the 60 amp goes to the main panel inside each unit via #4 alum. All are done inside metal conduit. All of the main panels inside the apartments have the nuetrals isolated from the grounds, however the grounds are attached to the condiut and not the panel. Two of the panels had a bond lug to the inside of the panel that were attached to the nuetral bus. The other two panels were not bonded to the nuetral. What am I missing here? Furthermore, the apartments are all electric baseboard heat. They are very small 1 br apartments but this just seems like 60 amp supply is insufficient. Am I wrong? Thanks, Tom
Tom, The #2 is ok and so is the #4. The way I read your post tells me that the apartments are only recieving 60 amp. Sounds like you need to upgrade if your heat is bb's. As for the "bond lug" that was attached to the "nuetral bus". That's improper. The ground wires are attached to the "metal conduit". If you look I am sure that you will find the "metal conduit" is attached to the panel. Hence, if your "bond lug" is attached to the "nuetral bus" you are no longer isolating the nuetral and ground.
Re: Is this panel proper???#7855 02/25/0208:00 PM02/25/0208:00 PM
Well, you could try doing a load calculation for the feeders, just follow the examples in the back of the NEC. If the breakers haven't been tripping & the connections don't show signs of overheating, you might let this sleeping dog lie, especially if the load calc works out.
Few things are harder to put up with than the annoyance of a good example.