ShipCalculators.com

Motor Synchronous Speed

Ns = 120·f / P - fundamental relationship between line frequency, pole count and a synchronous/induction motor's magnetic-field speed.

Motors
Loading calculator…

Formula, assumptions, and limits

Ns=120fPN_s = \frac{120 \cdot f}{P}
SymbolMeaningUnit
ffLine frequencyHz
PPNumber of magnetic poles
NsN_sSynchronous (field) speedrpm

Source: IEC 60034-1 - Rotating electrical machines

In short

Ns = 120\u00b7f / P - fundamental relationship between line frequency, pole count and a synchronous/induction motor's magnetic-field speed.

Learn the theory Marine Electrical Generation and Distribution