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-   -   Install 200amp subpanel from 400amp main panel (https://www.askmehelpdesk.com/showthread.php?t=216800)

  • May 17, 2008, 03:24 AM
    U079310
    Install 200amp subpanel from 400amp main panel
    Building a new home. The detached garage has a 400amp service panel which is hardly used (has 2 20amp breakers for garage lights). I want to install a 200amp panel in the house basement which is located about 100 feet from the garage panel.

    I have purchased and installed the 200amp panel in the house basement. What is the best way to now connect the 200amp panel to the 400amp panel. I have installed smaller amperge subpanels previously but do not seem to find any 200amp breakers to do this same function within the 400amp main panel.

    Thank you.
  • May 17, 2008, 03:53 AM
    stanfortyman
    Let me get this straight. You have a single 400A panel in the garage? For just the garage?
    What else is this feeding?
    How is the house being fed?

    You will likely not find a 200A branch circuit breaker. Most panel busses have a maximum branch circuit rating of 100 or 125 amps.
  • May 17, 2008, 04:05 AM
    U079310
    [QUOTE=stanfortyman]Let me get this straight. You have a single 400A panel in the garage? For just the garage?

    Yes Stan you have this correct. The 400A panel is just for the garage. The guy who built the garage was eventually planning on building a home but sold to me before he did so. The 400A panel currently has (2) 20A breakers just for garage lighting.

    The home I mentioned is new, there is nothing providing power to it now. That is the purpose of the 200A panel I purchased for the home basement.
  • May 17, 2008, 04:44 AM
    stanfortyman
    Ahhhh. So the garage was existing, the home is new-new. Got it.

    Well, like I said, it is rare to have a typical panel that will accept a 200A branch breaker.
    I would go to a supply house and give them the model number of the panel and see what branch circuit breakers are available for it. A home center will be useless for this.

    In the meantime post that info here and we'll can see what we come up with.

    You'll need a 2" or 2.5" conduit and 4/0AL or 2/0CU wire to feed this panel.

    Also, where is the phone and cable coming from?
    And what code cycle are you under for electrical?
    These are important questions.
  • May 17, 2008, 04:57 AM
    U079310
    Have already checked for breaker possibilities on the GE 400A main panel. The largest breaker available is 100A.

    I live in Michigan so my handout from the County inspector says that they enforce "Michigan State Electrical Code 2002 which includes the NEC Code 2002".

    Phone and cable in a separate trench in from the road, no problems there. This may be stupid but could you take (2) 100A breakers and run 1 hot wire from each to the lugs on the 200A panel in the house ?
  • May 17, 2008, 05:13 AM
    stanfortyman
    This is what I do NOT like about using a 400A panel in a residential setting. They are foolish IMO.
    With two 200A panels in parallel you could have replaced one with a feed-through panel and sent 200A to the house.
    Your situation is one of the drawbacks of using a single 400A panel.



    Quote:

    Originally Posted by U079310
    This may be stupid but could you take (2) 100A breakers and run 1 hot wire from each to the lugs on the 200A panel in the house ?

    Well, not a stupid question, but NO you certainly cannot do that.


    I hate to say this, but without seeing the actual setting, I'm not sure what I'd do in your situation. Replacing the 400A panel with two 200's is looking like the easiest thing to me.
    It might actually be cheaper and easier still to simply bring a new 200A service to the house from the road.
    Maybe you can open a machine shop in the garage to take advantage of the awesome service out there?
  • May 17, 2008, 01:05 PM
    KISS
    Check out the I-line distibution panels from squareD.

    http://ecatalog.squared.com/pubs/Ele...0120BR9202.pdf

    At least you'll be able to distribute power properly.
  • May 17, 2008, 05:44 PM
    stanfortyman
    I-Line? In a residence?? :eek:
    Heck, by the time you buy just the panel and breakers you could install a whole new 200A residential service at the house.
  • May 17, 2008, 08:08 PM
    Handyman2007
    Why not remove the 400 amp from the garage, relocate the service to the house (200amp) then run a separate 60 amp sub panel to the garage? That is the simplist way as far as I am concerned. I am surpised that the utility co even allowed a 400amp service just in a garage without any building plans for a house first??

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