The formula for calculating watts using DC volts:
Power, measured in watts (W), is proportional to the product of voltage, measured in volts (V), and current, measured in amps (A)
P = V× I
The formula for calculating watts using AC Single Phase volts:
The power, measured in watts (W), is equal to the power factor, PF, multiplied by the phase current, measured in amps (A), and multiplied by the RMS voltage, measured in volts (V).
P = PF × I × V
The formula for calculating watts using AC Three Phase volts:
Calculation using the voltage from Line to Line:
The power, measured in watts (W), is calculated as the square root of three times the power factor, PF, multiplied by the phase current, measured in amps (A), and multiplied by the line-to-line RMS voltage, measured in volts (V):
P = √3 × PF × I × VL-L
Calculation using the voltage from Line to Neutral:
The power, measured in watts (W), is equal to three times the power factor, PF, multiplied by the phase current, measured in amps (A), and multiplied by the line-to-neutral root-mean-square voltage, VL-N, in volts (V):
P = 3 × PF × I × VL-N
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