How much power will a 3 phase, 225 amp main breaker supply?
Assuming most audio gear is 120 volt, a 225 amp, 3 pole main breaker will deliver 225 amps in each leg forever. Code dictates that breakers be derated to 80% of their indicated handle current. Example: 225 amps per leg x 3 = 675 amps x 80% derating = 540 amps @ 120 volts. The continuous power rating is 540 amps x 120 volts = 64,800 watts or 64.8 KVA Audio systems typically require a high inrush current to charge the power supply capacitors and then only need high current to keep the capacitors charged when a sustained high output is encountered. A conservative approach for audio systems is to figure a maximum duty factor of 50% so the panel could power amplifiers requiring up to 129,600 input watts. The actual audio output power will be contingent on amplifier efficiency.
