A 15kva UPS feeds a 3 Phase 208V distribution Panel.
Almost every branch circuit in the panel is occupied by a single pole breaker in the ON position. According to the human interface on the UPS, the output is currently 20 amps, 30amps and Zero amps on phases A, B, and C. The interface also states a 0.86 Power Factor.
The customer would like to place an existing nearby 3 Phase 208V distribution panel on UPS power. You remove the panel cover and load check the three incoming panel feeders. The meter reads 20 amps, 10, amps, and 12 amps.
The customer has verified that all loads in both panels are on prior to checking the output on the UPS, and the incoming feeder loads on the second panel.
Assuming a power factor of 0.80 on the second panel, can the customer feed the second panel with a correctly sized three pole breaker off of a circuit in the UPS panel without overloading the UPS, or, will the customer have to purchase a new UPS?
Note: assume you do not know if the panels are phased the same but that you would be able to correctly identify phasing and move loads as necessary to balance the total load.
All Loads are Wye-Connected.
Click for the solve:
Continue reading “Calculating Three Phase UPS Capacitiy Serving Three Phase Distribution Panels”