Motor speeds according to poles
Motor speeds according to poles
(OP)
I was looking for a table of speeds of 3 phase motors according to no of poles for 50Hz. Does anyone know the whereabouts of one of these?
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
Motor speeds according to poles
|
RE: Motor speeds according to poles
where n = rpm
f = frequency - cpm
p = number of pairs of poles
So :
2 poles - 3000 rpm
4 poles - 1500 rpm
8 poles - 750 rpm etc
(synchronous speeds - ie not counting slip)
RE: Motor speeds according to poles
Although the f in the numerator has not been clearly defined.
I would prefer to say sync speed = 2*FL / poles
where FL is line frequency.
Put the units in and you'll see the need for any additional required unit conversions such as 60rpm / hz.
Actual speed for general purpose NEMA design B motor is required to be in the range 0-5% below sync speed, and usually in the range 0-1% below sync speed.