mark32
Senior Member
- Location
- Currently in NJ
A fellow electrician, whom I just met, is redoing the service on his house because he is turning it into a two family so he wants to add a meter and a sub panel, of which would be located upstairs.
His plans are as follows: 4/0 AL SE into metallic trough (3R) via a hub, nipple out of trough with metallic offset nipples, one goes to 100a meter, the other into a 200a meter, then LB out of each meter and run into basement where one feeds 200a main panel, the other feeds a 100a disconnect that in turn feeds sub upstairs. I asked him how he was going to bond the trough, he said the nipples coming up from the meters will accomplish that. I said I don't think so but didn't push the topic as I've never done such an install, the same goes for the tap for the 100a side. He was going to tap it with #2 AL but then went up to 2/0 AL. Inside he already has, I believe, #4 copper AC feeding the sub which now that I think of it could be an issue as AC's ampacity is to be found in the 60c column yes? So instead of the 100a disc use a 100a main breaker panel and feed the #4 copper with a 70a breaker? Excuse me for getting side tracked, so here is how I envision the service assembled with the parts he wishes to use: Tap or bolt (Which is preferred?) a distribution block to the trough and terminate the neutral to that, then use bonding bushings on the offset nipples on the trough side and bond that to the block, if he was using a metallic raceway leaving the meters (Which he's not) use bonding bushings on the connectors when they enter their respective panels/disconnects. Oh, and use #1 AL for the 100a tap. What do you think?
His plans are as follows: 4/0 AL SE into metallic trough (3R) via a hub, nipple out of trough with metallic offset nipples, one goes to 100a meter, the other into a 200a meter, then LB out of each meter and run into basement where one feeds 200a main panel, the other feeds a 100a disconnect that in turn feeds sub upstairs. I asked him how he was going to bond the trough, he said the nipples coming up from the meters will accomplish that. I said I don't think so but didn't push the topic as I've never done such an install, the same goes for the tap for the 100a side. He was going to tap it with #2 AL but then went up to 2/0 AL. Inside he already has, I believe, #4 copper AC feeding the sub which now that I think of it could be an issue as AC's ampacity is to be found in the 60c column yes? So instead of the 100a disc use a 100a main breaker panel and feed the #4 copper with a 70a breaker? Excuse me for getting side tracked, so here is how I envision the service assembled with the parts he wishes to use: Tap or bolt (Which is preferred?) a distribution block to the trough and terminate the neutral to that, then use bonding bushings on the offset nipples on the trough side and bond that to the block, if he was using a metallic raceway leaving the meters (Which he's not) use bonding bushings on the connectors when they enter their respective panels/disconnects. Oh, and use #1 AL for the 100a tap. What do you think?
