Lighting Study

[rmonroe]

I'm about to do a estimated cost study on our lighting usage. We use 3Ph 480VAC Siemens load centers for our 1Ph 277VAC lighting.

My question is, when I check current draw on all three phases do I calculation each phase separatly?

Thanks

rmonroe

 

[ron]

Re: Lighting Study

If you measure 20A on each of the three phases
for phase A 277*20=5540W
for phase B 277*20=5540W
for phase C 277*20=5540W
totaling 16,620W

The other method is 480*20*sqrt(3)= 16,627W which is the same if you consider the rounding of the sqrt(3) is off slightly.

So, same answer either way.

 

[rmonroe]

Re: Lighting Study

Thanks for the information.

rmonroe