Custom Search
Synchronous Speed of Electrical Motors
The speed at which an induction motor will operate depends on the input power frequency and the number of electrical magnetic poles in the motor
Sponsored Links
The synchronous speed of an induction motor is based on the supply frequency and the number of poles in the motor winding and can be expressed as:
ω = 2 60 f / n (1)
where
ω = pump shaft rotational speed (rev/min, rpm)
f = frequency (Hz, cycles/sec)
n = number of poles
The rotational speed at different frequencies and number of poles can be listed as:
| Pump shaft rotational speed - ω - (rev/min, rpm) | ||||||
| Frequency - f - (Hz) |
Number of poles - n | |||||
| 2 | 4 | 6 | 8 | 10 | 12 | |
| 10 | 600 | 300 | 200 | 150 | 120 | 100 |
| 20 | 1200 | 600 | 400 | 300 | 240 | 200 |
| 30 | 1800 | 900 | 600 | 450 | 360 | 300 |
| 40 | 2400 | 1200 | 800 | 600 | 480 | 400 |
| 501) | 3000 | 1500 | 1000 | 750 | 600 | 500 |
| 602) | 3600 | 1800 | 1200 | 900 | 720 | 600 |
| 70 | 4200 | 2100 | 1400 | 1050 | 840 | 700 |
| 80 | 4800 | 2400 | 1600 | 1200 | 960 | 800 |
| 90 | 5400 | 2700 | 1800 | 1350 | 1080 | 900 |
| 100 | 6000 | 3000 | 2000 | 1500 | 1200 | 1000 |
- Motors designed for 50 Hz are common outside U.S
- Motors designed for 60 Hz are common in U.S
Variable Frequency Drive
With a variable frequency drive its possible to modulate the speed of the motor by changing the frequency supplied to the synchronous motor. The relation between motor speed, frequency and number of poles in the motor can be found in the table above.
Sponsored Links
Search the Engineering ToolBox
Custom Search
Engineering ToolBox - SketchUp Edition - Online 3D modeling!
Engineering ToolBox - SketchUp Edition - enabled for use with the amazing, fun and free Google SketchUp