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3-Phase Power Calculator

Calculates voltage, current, real power (kW), apparent power (kVA), and reactive power (kVAR) in 3-phase systems.

Results

Apparent Power
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Real Power
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Reactive Power
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Line Current
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Phase Current
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Phase Voltage
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Additional Info

Standard IEEE/IEC 3-phase formulas. For motor loads, use actual motor nameplate FLA if available.

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How to Use This Calculator

1. Choose what to solve for. Select Power (kW/kVA), Current (Amps), or Voltage based on what you need to find.

2. Enter the known values. For power calculation, enter voltage and current. For current calculation, enter voltage and power (kW). The power factor defaults to 0.85 for typical motor loads.

3. Review all results. The calculator shows apparent power (kVA), real power (kW), reactive power (kVAR), line and phase currents, and phase voltage.

3-Phase Power Formulas

kVA = V x I x 1.732 / 1000

kW = V x I x 1.732 x PF / 1000

kVAR = sqrt(kVA^2 - kW^2)

Amps = kW x 1000 / (V x 1.732 x PF)

Wye: V_phase = V_line / 1.732, I_phase = I_line

Delta: V_phase = V_line, I_phase = I_line / 1.732

Frequently Asked Questions

What is the 3-phase power formula?
kVA = V x I x 1.732 / 1000. kW = kVA x PF. Current = kW x 1000 / (V x 1.732 x PF). The 1.732 factor is the square root of 3.
What is a typical power factor for motors?
Typical motor power factors are 0.80 to 0.90 at full load. Lightly loaded motors can drop to 0.50-0.60. Resistive loads are 1.0.
How do I convert kVA to amps for 3-phase?
Amps = kVA x 1000 / (Voltage x 1.732). For example, 45 kVA at 480V = 45000 / (480 x 1.732) = 54.1 amps.

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