A 480Y/277 V lighting panelboard has the following loads:

• Lighting (4 circuits at 277 V) with a total load of 16.0kVA at PF = 0.95 (continuous load)

• Appliances (2 circuits at 277 V) with a total load of 9.0 kVA at PF = 0.90 (noncontinuous load)

• A/C system (1 circuit at 480 V) with a total load of 15.00 kVA at PF = 0.85 (continuous load)

(a) Determine the size of all the circuit breakers in the panelboard (provide the trip rating).

(b) Show a schedule for the panelboard with the least load unbalance between the three phases. Determine the percent load unbalance (based on total power in each phase) for the proposed schedule.

(c) Select the proper main circuit breaker for the panelboard (provide both the frame size and the trip rating).