Mike Dolt Enterprises
Mike Dolt Enterprises
User: jbelectric777, Location: NJ/PA
Asked on: Sunday, May 1, 2011 at 3:30 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:50 am EDT
Question: Hey guys, I just want some feedback on use permitted for aluminum type SEU and SER as service entrance, specifically its ampacity derating. I am pretty sure I am correct but non the less, here's the scenerio. I understand that note (8) allows the use of #2 type SEU and SER as 100 amp service conductor/s for single and two family dwellings only. I take that as it cannot be used as service entrance and have protection more than 100 for 1) R3 multi family 2) commercial occupancies. So in the case of a multi family apartment building each "dwelling" must have a 100 amp service BUT it cannot be using the number 2 AWG aluminum. It would have to be sized in accord with the table/s etc in 310-16 or be protected at the next common (code given) size, which would be 90amps. So if feeders were pulled in an R3 that were #2 Al they can only have 90 amp protection but at the same time the apartment service size would be in violation because it is a dwelling and the minimum size service is 100 amp. Who say yey and who say ney ? Thanks in advance, Jim
Yes, you are correct.
According to Note 8 of Table 310.16, aluminum type SEU and SER can be used as service entrance conductors for single-family and two-family dwellings only. However, this use is limited to a maximum ampacity of 100 amperes.This means that #2 AWG aluminum SEU or SER cannot be used as service entrance conductors for multi-family dwellings (R3) or commercial occupancies, as these require ampacities greater than 100 amperes.In the specific case of a multi-family apartment building, each dwelling must have a minimum service size of 100 amperes. If #2 AWG aluminum SEU or SER is used, it can only have 90 amp protection, which is below the minimum required service size.Therefore, the use of #2 AWG aluminum SEU or SER as service entrance conductors for multi-family dwellings or commercial occupancies is prohibited by the NEC. Flag for review