Asynchronous Induction Motors - Electrical Properties
Typical electrical motor data like nominal current, fuse, start ampere, size of contactor and circuit breaker - for asynchronous induction motors.
The table below can used to determine electrical data for asynchronous 380 Voltage induction motors.
380 Voltage 50 Hz motors are commonly used in Europe. Note that the nominal voltage of existing 220/380 V and 240/415 V systems evolves toward the IEC recommended value of 230/400 V.
| Rated Power | Nominal current - In - (A) | Directly Fused (A) | Star - Delta Started (A) | Star - Delta contactor - In - (A) | Circuit Breaker - In - (A) | |
|---|---|---|---|---|---|---|
| kW | HP | |||||
| 0.2 | 0.3 | 0.7 | 2 | 2 | 16 | |
| 0.33 | 0.5 | 1.1 | 2 | 2 | 16 | |
| 0.5 | 0.7 | 1.4 | 2 | 2 | 16 | |
| 0.8 | 1.1 | 2.1 | 4 | 4 | 16 | |
| 1.1 | 1.5 | 2.6 | 4 | 4 | 16 | |
| 1.5 | 2 | 3.6 | 6 | 4 | (16) 22 | 16 |
| 2.2 | 3 | 5.0 | 10 | 6 | (16) 22 | 16 |
| 3 | 4 | 6.6 | 16 | 10 | (16) 22 | 16 |
| 4 | 5.5 | 8.5 | 20 | 16 | (16) 22 | 16 |
| 5.5 | 7.5 | 11.5 | 25 | 20 | (16) 22 | 16 |
| 7.5 | 10 | 15.5 | 35 | 25 | (25) 22 | 25 |
| 11 | 15 | 22.2 | 35 | 35 | (40) 30 | 40 |
| 15 | 20 | 30 | 50 | 35 | (40) 30 | 40 |
| 22 | 30 | 44 | 63 | 50 | (63) 60 | 60 |
| 30 | 40 | 57 | 80 | 63 | (63) 60 | 60 |
| 45 | 66 | 85 | 125 | 100 | 90 | 100 |
| 55 | 75 | 104 | 160 | 125 | 110 | 100 |
| 75 | 100 | 140 | 200 | 160 | 150 | 200 |
| 90 | 125 | 168 | 225 | 200 | 220 | 200 |
| 110 | 150 | 205 | 300 | 250 | 220 | 200 |
| 132 | 180 | 245 | 400 | 300 | 300 | 400 |
| 160 | 220 | 290 | 430 | 300 | 300 | 400 |
| 200 | 270 | 360 | 500 | 430 | 480 | 400 |
| 240 | 325 | 430 | 630 | 500 | 480 | 480 |
Full-voltage, single-speed motor starters
Full-voltage starters (manual and magnetic) apply full voltage directly to motor terminals.
Reduced-voltage, single-speed motor starters
Some machines or loads may require a gentle start and smooth acceleration up to full speed.
Many starters apply reduced voltage to motor windings, primary resistor, primary reactor, autotransformer and solid state. Part winding and wye-delta starters can also provide reduced-voltage starting, although technically they are not reduced-voltage starters.
Motor Protection
Motors should have protection for themselves, in the branch circuit, and in the feeder line. Protection provided by fuses and circuit breakers guards against fault conditions caused by short circuits or grounds and over currents exceeding locked-rotor values.
