Number of Pole Pairs
The number of pole pairs determines the synchronous speed of the three phase motor.
nsync = synchronous speed
f = frequency of the 3-phase power supply
p = number of pole pairs of the 3-phase motor
Kindly note that the above noted relation results in revs per second if the frequency unit is Hz.
| Pole pair numbers | 1 | 2 | 3 | 4 | 5 | 6 |
| Synchronous speed (at 50 Hz) n [rpm] | 3000 | 1500 | 1000 | 750 | 600 | 500 |
| Synchronous speed (at 60 Hz) n [rpm] | 3600 | 1800 | 1200 | 900 | 720 | 600 |
The rated full-load speed of three phase asynchronous motors is, due to slip, a few percent below the synchronous speed.
