Review on STETION 50 Amp Circuit Breaker with Manual Reset for Trolling Motors, Car Marine, Boat, ATV. Provides Power Protection for Audio Systems. Fuse 12V-48VDC, Waterproof (50Amp) by Mark Crawford

I bought a 250 amp circuit breaker and am trying to use a circuit breaker between the battery pack and the inverter. These switches are either fake or a cheap, untested copy of a real marine DC switch. The breaker has a very high series resistance of 1.6mΩ, which means that if 250 amps flow through it (due to 157 watts of power dissipation) it will trip instantly. The calculated trip point at 20 amps DC test current was 33 amps. If designed correctly, the circuit breaker should trip after a few minutes when the nominal tripping current is applied. These switches may be ok if the trip current is less than 60A and the switch was actually calibrated when manufactured. Such circuit breakers are easily damaged (and spot welded) when the circuit breaker between the battery and the inverter (or power amplifier) is closed due to the excessive inrush current caused by the capacitor bank in the inverter (or amplifier). I recommend temporarily connecting the light bulb through a breaker until the input power of the inverter reaches the battery voltage, and then closing the circuit breaker.