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Thread: Downgrading main breaker size

  1. #1
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    Downgrading main breaker size

    Is there any Code that prohibits downgrading the main breaker size in a 200A panel to 150A? Let's say I buy an old run-down house, demolish it, and build a new house in its place. The neighborhood uses overhead service drops only good for 150 amps. However, I want a panel with 40 spaces in it, which only comes in 200A. Could I install 150A service, change the main breaker to a 150A, and then use the panel as a 150-amp panel?

  2. #2
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    Yes.
    "Electricity is really just organized lightning." George Carlin


    Derek

  3. #3
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    Agreed, yes you can do that. It's very common when doing PV installs to downgrade main breakers from 225 to 200 or 200 to 175 so that you can install a larger solar backfeed breaker. However, you will want to consult with your local power utility. Probably no issue but they might have something to say about it. Also, the utility might spec a certain rating for the available inrush current your main breaker needs to have. If they spec 22k and you install a 10k you'll have an issue with them.

    Also, just my 2 cents, but I recommend installing as many of your circuits as you can in one or more sub panels inside the building instead of in your main meter panel.

  4. #4
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    Quote Originally Posted by jeff48356 View Post
    The neighborhood uses overhead service drops only good for 150 amps.
    Is this per your POCO?

    Also, you can probably install a MLO subpanel under a 150 amp panel for less than the cost of replacing the main breaker of a 200 amp panel.

  5. #5
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    Quote Originally Posted by jeff48356 View Post
    I want a panel with 40 spaces in it, which only comes in 200A.
    I found this: https://www.homedepot.com/p/Square-D...PCVP/204836366

    and this: https://www.homedepot.com/p/GE-150-A...C64K/301157609

    and this: https://www.homedepot.com/p/GE-Power...5C42/100117803

  6. #6
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    Quote Originally Posted by jeff48356 View Post
    Is there any Code that prohibits downgrading the main breaker size in a 200A panel to 150A?
    Let me give you something to think about, what size safety switch would you use for 40 amp fuses?
    Quote Originally Posted by jeff48356 View Post
    Let's say I buy an old run-down house, demolish it, and build a new house in its place. The neighborhood uses overhead service drops only good for 150 amps.
    Are saying your POCO only allows 150 A services?

    Quote Originally Posted by jeff48356 View Post
    Could I install 150A service, change the main breaker to a 150A, and then use the panel as a 150-amp panel?
    As Jumper said, yes.

    Roger
    Moderator

  7. #7
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    Although a very small number of POCOs (including Los Angeles DWP) will not allow you to connect a 150A service to a 200A panel, even with a 150A main breaker.

    Sent from my XT1585 using Tapatalk

  8. #8
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    Quote Originally Posted by GoldDigger View Post
    Although a very small number of POCOs (including Los Angeles DWP) will not allow you to connect a 150A service to a 200A panel, even with a 150A main breaker.

    Sent from my XT1585 using Tapatalk
    More stupidity from clueless POCO's.

    Roger
    Moderator

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