Circuit breaker rating question

Discussion in 'General Electronics Chat' started by inwo, Jan 24, 2014.

  1. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
    I have a din mounted C40-3 breaker that is tripping when starting a motor in cold weather.

    On a cold morning it will trip 3 or 4 times before it starts.

    This is the feed to outdoor control panel. Not the motor protection breaker or overloads.

    I was thinking of upping to a "D" curve, but found a "K".
    Wonder if that seems a good choice?

    From chart it looks like "K" is industrial rated, and trips "short circuit" just a little quicker than "D" but slower than the "C" that is in use.

    The "C" has been swapped once. Motor current is normal.
    Last edited by a moderator: Jan 25, 2014