Speed Controller For Single Phase Motor

[seppoalanen]

Ups

 

[504bloke]

Rewind the motor to the local Area electrical spec

If you rewind the motor, presuming the motor is plated 50Hz and you rewind to 60Hz or vice versa (bearin in mind that most modern motors are dual 50/60Hz plated nowadays) then that wont affect the speed at all.

 

[bernie_carlton]

I've heard of rewinding a motor to a different voltage but not to a different frequency. I thought the dual frequency rating indicated that it could take the heating effects at the lower frequency though it wouldn't produce the same RPM. maybe I'm just really confused.

 

[jraef]

No you're not confused. Motor speed = 120 x Hz/Number of poles. Winding can change the number of poles, but that changes speed in gross amounts, i.e. 4 poles = 1800RPM, 6 poles = 1200RPM (synchronous speeds). The cost of changing poles on a 1HP motor would far exceed the cost of buying a new motor.

 

[WireGuy1950]

Are you sure that the problem is just the base motor speed?
If it were running at 50Hz it would only be 20% slower.
Maybe the overall speed is too fast for the application, what was this grinder marketed as?
Probably the best solution would be some sort of gear change, maybe a reeves drive to help determine the optimum speed.

 

[rsdoran]

Are you sure that the problem is just the base motor speed?
If it were running at 50Hz it would only be 20% slower.
Maybe the overall speed is too fast for the application, what was this grinder marketed as?
Probably the best solution would be some sort of gear change, maybe a reeves drive to help determine the optimum speed.

The issue is the original frequency of the motor and supply was 50HZ and now it is running 60Hz, that means base speed went from 1500 to 1800, a 20% increase. The added speed appears to be "slinging" the rice.