Load Calculation for 2-phase and 3-phase equipment

1- P (3phase)=3Vph x Iph x PF=1.73Vl x Iph x PF

2- P(1phase)=Vph x Iph x PF

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Hi Guest;

1. 3 Phase Apparent Power "S" (VA) = 3 x V phase x I phase = sqrt. 3 x V line x I line

2. 2 Phase Apparent Power "S" (VA) = 2 x V phase x I phase

Phase wise, its 3 single phases and 2 single phases.

Phase voltage is voltage between one phase and neutral.

Line voltage is voltage between one line and another (with respect to the other line).

You have to consider the power factor for a 3 phase calculation. If you don't know the power factor then a good ball park figure to use is 0.6.

Hi Andy,

Yes power factor must be considered for kW loading at that instant of voltage and current measurement.

For 3 phase system, P = sqrt. 3 x V line x I line X Cos(ø)

Where, Apparent Power "S" (VA) = sqrt. 3 x V line x I line.

As, Power (w) = S x P.F,

From which one can determine the kW loading and the kVA loading. Where, with some power utilities, the maximum billing on power is focused on the kVA. From which injecting reactive power, kVAR, will correct power factor reducing the kVA loading, and savings on money. This is applicable to large facilities and factories.

Anyway, cheers!