120 gallon

4500 watt rated non simtanious with 2 elements

208 volts

I was told by an inspector at a arm forces camp that the 20 amp 2p CB is under rated and the 2p 60 amp disconnect was over sized for a 4500 watt rated non simontanious water heater. As I caculated it 4500 watts @ 208 volts to be 12.5 amps that is 62.5% of 20 amps CB. It was told to install a 60 amp 2p CB to comply. Can someone enlighten me if I am wrong