Electric Motors - IEC and NEMA Standard Torques
IEC and NEMA torque classifications of electrical motors.
NEMA (National Electrical Manufacturers Association) has classified electrical motors in four different NEMA designs where torque and starting-load inertia are important criteria.
Torques of the IEC Design N motors are in general close to NEMA Design B motors. IEC Design N and NEMA Design B are the most commonly used industrial types.
Torques of the IEC Design H are nearly identical to NEMA Design C.
| Power (hp) | 2 Pole | 4 Pole | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Locked Rotor Torque | Pull Up Torque | Break Down Torque | Locked Rotor Torque | Pull Up Torque | Break Down Torque | |||||||
| 3 | 170 | 160 | 110 | 110 | 200 | 230 | 180 | 215 | 120 | 150 | 200 | 250 |
| 5 | 160 | 150 | 110 | 105 | 200 | 215 | 170 | 185 | 120 | 130 | 200 | 225 |
| 7.5 | 150 | 140 | 100 | 100 | 200 | 200 | 160 | 175 | 110 | 120 | 200 | 215 |
| 10 | 150 | 135 | 100 | 100 | 200 | 200 | 160 | 165 | 110 | 115 | 200 | 200 |
| 15 - 20 | 140 | 130 | 100 | 100 | 200 | 200 | 150 | 150 | 110 | 105 | 200 | 200 |
- 1 lb ft = 1.356 Nm
