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Inrush current and circuit breakers

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  1. #1
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    Default Inrush current and circuit breakers

    Not quite sure how this works so asking the brains trust.
    We just bought a new amplifier to power the H/T subwoofers.
    It's a Yamaha P7000s and at turn-on it has a fairly massive inrush current of 20 Amperes, the rest of the H/T amp set-up only pulls 5.5A at start -up and the TV ~1.5A
    This is the dedicated 4mm<2 Audio circuit with a 32A breaker on it.
    Which one do I switch on first assuming the TV is already on. Yes the new amp may be a tad overkill but the price is right
    It's rated 1100 watts per channel into a 4R load and 750 into an 8R load at 50%.
    "A big boy did it and ran away"

    Legal disclaimer denying responsibility to be inserted here.

  2. #2
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    20A inrush is actually nothing. Depending on the type of breaker, the short circuit magnetic trip current will be multiples of the thermal breaker current, so with a 32A breaker I wouldn't be concerned at all. I have AC/DC lighting drivers that have an inrush of 55A each, and you can put up to 16 of them on a single type C breaker.

  3. #3
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    I wasn't sure as my other big amp only has an inrush current of 15A and the other two maybe half that and the lights dim when I turn on that system. Thanks fot the information.
    It's the only amplifier I've ever bought that comes with a 15A plug
    "A big boy did it and ran away"

    Legal disclaimer denying responsibility to be inserted here.

  4. #4
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    it should be fine. if you had issues with it tripping you could swap the circuit breaker to a D curve breaker.
    Thats what we do for motors where the inrush current could be 7 times what the rated current of a motor would be.

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