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# Calculating 3 phase kva

Discuss Calculating 3 phase kva in the Industrial Electrician Talk area at ElectriciansForums.net

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#### nickblake

Electrician's Arms
CCTV / Alarms
Solar Guru
DIY
My brains switched off chaps and i can remember how to calculate 3 phase kva

i know its V x I x 1.73 / 1000

so is it 230 or 400 x I x 1.73 / 1000

fee a right numpty cant belive ive forgotten it not done 3 phase calcs for a while please enlighten me to the correct figures then ill give my self a good slapping

E

#### ezzzekiel

P=1.732 X vl X iL X PF

#### ukpablo

##### Regular EF Member
Example 1

A 415 volt, three phase generator provides 200 Amp. Calculate the kW and kVA of this generator.
kW = V x I P.F. x ÷ 1000 = 415 x 200 x 0.8 x 1.732 ÷ 1000 = 115 kW
kVA = kW ÷ P.F. = 115 ÷ 0.8 = 143 kVA
Example 2

To calculate the current (Amps) available from a 150 kVA generator at 415 Volts
kW = V x I x √3 ÷ 1000 Therefore I = kVA x 1000 ÷ V x √3 = 208 Amps
Example 3

To calculate the size of a generator required to provide 150 Amps @ 440 Volt
kW = V x I x  ÷ 1000 = 440 x 150 x 1.732 ÷ 1000 = 114 kW

#### pushrod

Electrician's Arms
VA = √3 x Vl xIl

since VA = watts/PF

edit and it will be 400V

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#### nickblake

Electrician's Arms
CCTV / Alarms
Solar Guru
DIY
Thanks guys the pennys dropped im in the process of giving myself a slap ,im a right bleary eyed parrot faced wassok duuuuuu

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