Branch Circuits

[pressone]

Does anyone know how many branch circuits I need for a connected lighting load of 140KVA that consists of 120V fluorescent fixtures on a 20A circuits? I have a 120/208V 3 Phase Supply. Thank You! George

[Ohm1]

I say 28-33!

[Wgoodrich]

140,000 volt amps for lighting at 120 volt rated flourecent light fixtures on continuous load. Equals 140,000 x 1.25 = 175,000 voltamps.

20 amps times 120 volts = 2,400 voltamps per 20 amp 120 volt circuit.

175,000 voltamp lighting load divided by 2,400 branch circuits = 72.91 general lighting branch circuits.

Adjust to next whole number answer is 73 - 20 amp 120 volt branch circuits.

Hope this helps

Wg

[Ohm1]

If what the OP posted is the correct wattage, then WG is correct. Yet, I bet dollars the OP added up all the lamps, and submitted a number.

For inductive loads, we need an ampere rating, rather than total wattage.
We are looking at an assumed 1,416 fixtures. Heck , if each fixture had a load of .8amps(120)=96(1.25)=120w[ea](1416)=169920W
20(120)=2400
2400/120=20 fixtures on each 20a circuit
1416/20=70.8 20A circuits or 71 circuits.

Good answer WG! :vroam: