Motor current calculator
Estimate the current drawn by a three-phase induction motor from its mechanical power (kW), the supply voltage, the power factor (cos φ) and the efficiency (η). This current is used to choose the cable section and the protection rating.
- Full-load current I
- 14.15 A
- DOL start (≈ 6×)
- 84.9 A
- Apparent power S
- 9.8 kVA
Indicative result: always verify against the standards and the installation method on site.
Formula
I = P / (√3 × U × cos φ × η)
Good to know
- Full-load current in steady state; the direct-on-line starting current is 5 to 8 times this value.
- Typical values: cos φ 0.8–0.86, efficiency 0.85–0.92 depending on power.