Calculate synchronous speed from supply frequency and pole count.
Synchronous speed depends only on frequency and pole count. An induction motor always runs slightly slower because slip is what generates rotor current and therefore torque. A four-pole motor runs at 1,500 rpm on 50 Hz and 1,800 rpm on 60 Hz, which is why equipment moved between regions changes speed by 20 per cent.
Motor Synchronous Speed
n_s = 120 f ÷ poles
n_s = 120 f ÷ poles Synchronous speed depends only on frequency and pole count. An induction motor always runs slightly slower because slip is what generates rotor current and therefore torque.
A four-pole motor runs at 1,500 rpm on 50 Hz and 1,800 rpm on 60 Hz, which is why equipment moved between regions changes speed by 20 per cent.
This calculator takes 3 inputs: Supply frequency, Number of poles, Slip at full load. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.