Results 1 to 3 of 3

Thread: 705.12(D)(2)

  1. #1
    Join Date
    Sep 2014
    Location
    CO
    Posts
    4

    705.12(D)(2)

    I have a new service at 200-amps with a 200-amp MCB. In order to install a larger PV system, I want to install a 175-amp MCB. The calculated loads in the building are less than 175-amps.

    Question: Can I install the service feeder to be rated at 175-amps as well instead of the 200-amps? Or does the service need to remain at 200-amps because of the bussing in the main board?

    It's not a lot of money but it could be if the service were much larger and it was a long run to the utility transformer.

  2. #2
    Join Date
    Oct 2009
    Location
    Austin, TX, USA
    Posts
    8,932
    Quote Originally Posted by Tank11 View Post
    I have a new service at 200-amps with a 200-amp MCB. In order to install a larger PV system, I want to install a 175-amp MCB. The calculated loads in the building are less than 175-amps.

    Question: Can I install the service feeder to be rated at 175-amps as well instead of the 200-amps? Or does the service need to remain at 200-amps because of the bussing in the main board?

    It's not a lot of money but it could be if the service were much larger and it was a long run to the utility transformer.
    I am pretty sure that the service conductors can be smaller if the breaker that is the main service disconnect has a lower rating.

  3. #3
    Join Date
    May 2011
    Posts
    3,934
    The NEC would allow what you want to do. I've run into one municipal utility that requires the service conductors to be rated the same as the panelboard, though.

    Another option (probably) would be to install a 'solar ready' panel with a 200A breaker and a 225A busbar. That might be more to the customer's liking if the original request was for a 200A service.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •