I got to thinking about huge power amps, like 1500 W and above. While I hope to never own one, my curiosity is piqued by the following question. Say a 1500 W amp is conventional Class-AB, and is optimistically 50% efficient. Then at full power, it is drawing 3000 W from the line cord. The circuit breaker on any standard outlet should pop in a jiffy, if the built-in fuse or circuit breaker doesn't open first. If this is true, what is the meaning of a 1500 W power rating? It must be based on very short duration peaks. Are there industry standards for defining the power rating or test conditions for PA amplifiers? Or is it Caveat Emptor?