100A Main Panel…..100A Branch Circuit?

Discussion in 'Electrical Forum discussion & Blog' started by lahabra, Jan 1, 2008.

  1. lahabra

    lahabra New Member

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    50
    Location:
    California
  2. 480sparky

    480sparky In the Trades

    Messages:
    149
    As long as the main panel has a 100a main breaker, there's nothing to prevent you from installing another 100a breaker for another panel.

    My question would be: Is the main panel already supplying another panel somewhere else? If so, you may run into problems overloading the main by putting over 100 amps of load on it.
  3. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,532
    Location:
    North Carolina
    You can feed three or four 100 amp subpanels with that set up as long as the calculated load on the main does not exceed 100 amps
  4. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    992
    Location:
    NY State, USA
    Typically a buss will have a maximum branch circuit breaker rating. Most are 100 or 125 amps.
  5. lahabra

    lahabra New Member

    Messages:
    50
    Location:
    California
    No.

    When I’m done the main will only feed the new sub panel. Then I will connect 21 new circuits to the sub panel.
  6. Bill Arden

    Bill Arden Computer Programmer

    Messages:
    584
    Location:
    MN, USA
    Nice main panel. :)

    I'm currently powering my 100A garage panel using a breaker coming out of my 100A house panel.

    The inspector was ok with it, but I know that I could trip the main if I turn everything on at the same time.

    Your case is better since the main panel only feeds the second panel and thus it is unlikely to overload the main panel.

    Edit: There is one thing you will have to deal with. The ground and neutral can only be tied together at the main and you then have to remove the ground screw in the second panel and run 4 wires to the main.
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