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View Full Version : How do you figure three phase amps when all you know is voltage and wattage.


Kingpen
Nov 8, 2011, 05:35 PM
How do you figure three phase amps. When all you know is the voltage and the wattage. Do not know the PF factor

tkrussell
Nov 9, 2011, 06:17 AM
For example, with the following values:

208 Volts 3 phase

15000 watts or 15 KVA

Assume .8 PF

VA (AC Watts)= E*I*PF*1.73

I= KVA/E*1.73*PF

Amps = 15000 watts divide by 208 volts times 1.73 times .8

Amps = 52.10 amps

If this is for resistance heat, no need for PF.