Home and plant
Turn kilowatts into amps.
Boards, motors, and feeders. No glass line. The figure does not replace a measurement on site.
Phase
- Current
- 4.18A
- Minimum step
- 6 A
Three-phase: I = (kW × 1000) / (380 × 1.732 × cos φ). Single-phase: I = (kW × 1000) / (220 × cos φ).
What this calculation says
Current is power divided by voltage and power factor. Three-phase puts 1.732 in the denominator. That is the three-digit stand-in for √3. Single-phase does not use 1.732.
Voltage is fixed here: 220 V for a home or small workshop, 380 V for three-phase. A supply that measures 230 V or 400 V changes the result. The calculation is not a measurement.
The breaker and contactor step is the first standard rating equal to or above the calculated current: 6, 10, 16, 20, 25, 32, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630 amps. Continuous load, starting current, and cable size can push that step up.
The formula is general. Field service is Pendik, Kurtköy, and Pendik Industrial Zone. The number is not a quote, a board design, or a wiring instruction.