400 V three-phase, 32 A per line at PF 0.9 → 19.95 kW real, 22.17 kVA apparent. Each star winding sees 231 V and 32 A.
Real power
19.95kW
32 A at 400 V, PF 0.9
Line current
32A
Apparent power
22.17kVA
Reactive power
9.66kVAr
Phase voltage
230.9V
V_ph = V_L ÷ √3
Phase (winding) current
32A
I_ph = I_L
Impedance per phase
7.22Ω
Motor shaft output
18.36kW
24.6 hp at 92% efficiency
Suggested breaker (≥125%)
40 A
continuous-load rule of thumb; check local code
Single-phase equivalent
96A at 230 V
why big loads use three phases
Standard three-phase voltages
| Line-to-line (V) | Phase, star (V) | Typical use | Amps for 20 kW | kW per 100 A |
|---|---|---|---|---|
| 208 | 120 | US commercial | 61.5 | 32.4 |
| 230 | 133 | old IEC / Japan | 55.7 | 35.9 |
| 400 | 231 | Europe, IEC | 32 | 62.4 |
| 415 | 240 | UK, Australia | 30.8 | 64.7 |
| 480 | 277 | US industrial | 26.7 | 74.8 |
| 600 | 346 | Canada | 21.3 | 93.5 |
| 690 | 398 | industrial / wind | 18.6 | 107.6 |
| 3,300 | 1,905 | MV motors | 3.9 | 514.4 |
| 6,600 | 3,811 | MV | 1.9 | 1,028.8 |
| 11,000 | 6,351 | MV distribution | 1.2 | 1,714.7 |
| 20,000 | 11,547 | MV distribution | 0.6 | 3,117.7 |
| 33,000 | 19,053 | MV / wind farm collector | 0.4 | 5,144.2 |
- Balanced load assumed (equal current in all three lines). For unbalanced loads compute each phase separately: P = Σ V_ph · I_ph · cos φ.
- Star: line voltage = √3 × phase voltage, line current = phase current. Delta: line voltage = phase voltage, line current = √3 × phase current. Total power is the same formula either way.
- Breaker size is a rough guide (125% of continuous current). Cable size, length, installation method and local regulations decide the real protection.