208V Three Phase Power Guide
A 208V three phase system is common in commercial panels. It serves motors, kitchens, shops, pumps, and computer rooms. The voltage is measured between any two lines. The calculator uses line voltage, line current, and power factor. It then estimates real power, apparent power, reactive power, energy use, and cost.
Why three phase matters
Three phase power delivers smoother torque than single phase power. Motors run with less vibration. Conductors can carry useful power efficiently. Yet the numbers can confuse users. Line voltage is not the same as phase voltage in a wye system. For most field work, the main input is line to line voltage. For this page, that value is normally 208 volts.
Power factor and load quality
Power factor shows how much apparent power becomes real work. A heater may run near one. A motor can be lower. Low power factor raises current for the same useful output. That can stress feeders and protective devices. This calculator displays kVA and kVAR so the load quality is easier to judge.
Demand, efficiency, and cost
Advanced estimates often need more than amps. Efficiency helps compare electrical input with useful output. Demand factor helps show expected operating load. Run hours and energy price turn demand kilowatts into cost. These values are estimates. Use measured data when safety or code compliance matters.
Phase balance check
Balanced phase current is important. Uneven current can heat equipment and reduce capacity. The optional phase fields compare A, B, and C line currents. The calculator reports average current and maximum imbalance. A small imbalance is usually better. Large imbalance should be reviewed by a qualified person.
Practical use
Enter the known value first. Choose whether you want power from current, current from kilowatts, or current from kVA. Keep voltage at 208 unless the measured line voltage differs. Add power factor from a meter, nameplate, or conservative estimate. Export the results for records. Always verify final designs with local rules and professional judgment. For maintenance teams, the export file is useful. It keeps voltage, current, power factor, and cost assumptions together. That record helps compare future readings. It also supports quick reviews before ordering equipment, sizing panels, or planning load changes during normal site planning tasks.