Upgrade UPS Power Distribution Board

The new load of the upgraded ACP-01 is 17 kVA. The current of the new load is 17,000/120 = 142 A. The ACDP breaker capacity needed is 142 x 1.25 = 177.4 A (~180 A). If you know the load diversity (or redundant load), the calculated rating may less than this.

The existing UPS PDB (ACDP) feeder breaker is 70 A only, so the breaker is under capacity.

You also need to make sure:

(1) The UPS capacity, ACDP and other UPS components are of enough rating to accommodate this new load including the other existing loads.

(2) The cable from ACDP to ACP-01 can carry the new load current. The cable ampacity shall be at least 180 A with voltage drop is witin 3%.

(3) The proper coordination of the breakers and fuses.

There are many other things to consider as well. So, I would suggest doing a thorough study of the UPS system before adding the new loads.

- MS

Camelito Quote "Got feeder from other UPS PDB (ACDP) with breaker 70AMP, 120VAC"

Are you sure the voltage is 120 volts. It is very unusual for a load that large to be using 120 volts. Sure it isn't 240 or 480 volts? Maybe 3 phase.

The way the Camelito described it is UPS PDB (ACDP) is main distribution panel and ACP-01 is subdistribution panel. The 70AMP breaker in ACDP is feeding the panel ACP-01. In this case the 70AMP, 120VAC is logical. Camelito can confirm it.