LOOK IN 220.32 OPTIONAL CALCULATION MULTIFAMILY AT TABLE 220.32 IT GIVES YOU THE NUMBER OF UNITS AND THE DEMAND FACTORS YOU CAN APPLY. ONE, YOU KNOW THAT THERE WERE 3 4/0 CABLES FEEDING THE OLD SERVICE AND IF I WAS DOING THIS I WOULD GO WITH A 800 AMP MAIN. YOU KNOW THAT THE MAX DRAW IS 1200 AMP, HOUSE SERVICE USUALLY NOT MUCH, SO IF YOU WOULD FOLLOW THE TABLE USE 41%, 492 AMPS. WELL THAT SOUND A BIT LIGHT, YOU KNOW THAT THE APARTMENT WERE BEING FED WITH ABOUT 600 AMPS BEFORE SO 800 AMP IS A GOOD COMPROMISE,
JOE OGLE