Hey Folks. A friend of mine just bought a condo and wants to rearrange some of the inside walls and have new wiring put in. We are going to do all of the branch circuit wiring ourselves but he's hiring a licensed electrician to put in a new panel. Here's where the big problem comes in... The service to the upstairs apartment/condo passes through the main panel of the downstairs unit. The neutral wire goes into the downstairs panel then another wire leaves that panel to go to the neutral bus on the upstairs panel. In other words, the neutral is daisy-chained. We know this is not acceptable, and we're pretty sure having the feed for the upstairs running through our panel is also unacceptable, but how to go about fixing these two problems is where a major difference in opinion and price comes in.
One electrician says the existing neutral can still be used for just the upstairs apartment by moving it, as well as the two hots, into a junction box. This means all three wires going to the upstairs unit will have splices in them. Meanwhile, a new neutral wire will get pulled to the downstairs panel and the existing hots will be re-used. The service comes from a ganged meter/main circuit breaker box about 30' away. This electrician says that a separate and unbroken ground wire does not need to be pulled because the panel in the apartment will be the "main panel" (have its own disconnect).
Another electrician says that because there is a main disconnect at the ganged meter box outside, the panels inside the apartments have to be treated as subpanels, and therefore need unbroken neutrals and grounds. So both apartments would need to have two new wires pulled to each panel, neutral and ground. He says no problem with having splices in the hots as long as they are in a junction box, not in the panel (he agrees with the first electrician on this point). Obviously, this guy's price is a lot higher than the first one's, but if the first one's won't pass then it really doesn't matter. Can someone shed a little light on this one???
NOTE - the existing service to each unit is 100A and uses #2 Aluminum THWN wires. Both electricians say #4 copper THHN is equivalent to #2 Aluminum THWN - correct? And no, the service ampacity can't be upgraded - the condo association prohibits it.
Thanks for any help - we're basically treading water until we get this squared away!
One electrician says the existing neutral can still be used for just the upstairs apartment by moving it, as well as the two hots, into a junction box. This means all three wires going to the upstairs unit will have splices in them. Meanwhile, a new neutral wire will get pulled to the downstairs panel and the existing hots will be re-used. The service comes from a ganged meter/main circuit breaker box about 30' away. This electrician says that a separate and unbroken ground wire does not need to be pulled because the panel in the apartment will be the "main panel" (have its own disconnect).
Another electrician says that because there is a main disconnect at the ganged meter box outside, the panels inside the apartments have to be treated as subpanels, and therefore need unbroken neutrals and grounds. So both apartments would need to have two new wires pulled to each panel, neutral and ground. He says no problem with having splices in the hots as long as they are in a junction box, not in the panel (he agrees with the first electrician on this point). Obviously, this guy's price is a lot higher than the first one's, but if the first one's won't pass then it really doesn't matter. Can someone shed a little light on this one???
NOTE - the existing service to each unit is 100A and uses #2 Aluminum THWN wires. Both electricians say #4 copper THHN is equivalent to #2 Aluminum THWN - correct? And no, the service ampacity can't be upgraded - the condo association prohibits it.
Thanks for any help - we're basically treading water until we get this squared away!