Hello Everybody here at ECT, I am new here to the forum and would like to get some info from you knowledgable members.
I am in the process of Rennovating a 12 apartment unit with 6 units on ground level and 6 units on second floor. this is all one building with a fire wall after every second unit running from ground level to roof top. The back of the apartments have wooden steps goin to the second story to a wooden deck approx 6' wide that runs the full lenght of the rear complex. The service coming in is a over head triplex from power co. that is connected to three 4/0 SEU cables. Each one of these cables are supplying a single phase 4 gang meter bank with 100 Amp load centers below and there are three banks of these along the rear of the aprtment with all the raceways being externally fastened. The units are being converted into condos and the local AHJ is requiring that the meters be grouped into one assembly located on the side of the complex for better access. my question is could i get some help on sizing the service entrance and the grounding for the meter bank assembly that i will need to purchase? Each apartment will remain 100 amps 120/240 (all plumbing has been converted to pvc.) The service will remain over head and above the banked assembly. I understand that i will have to provide the interuping rate and what size main prior to ordering of the assembly. im sure i left some things out but any help would be greatly appreciated.
The square footage is 550, the heat and range are gas, hot water is 3800 watts, the a/c is 13.5 amps. the washer and dryer are a combination unit and i have not seen the name plate for this but i know the two together call for a 20 amp circuit. (small compact unit). all of these apartments are the same setup.
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,