2 speed single phase ac motor winding connections

[arcelectric]

Lafert ac motor single phase 2 speed with 2 groups of leads for the windings. It is a capacitor run motor with no start winding . 3 leads to each speed and no centrifugal switch . I am unable to get high speed to run at rated speed . runs but at low speed with a hum noise . I can not get details from manufacturer and no local motor winders able to offer assistance . Any suggestions . anyone have this problem before . the winding meter through good and of equal resistance . no opens or grounds . Arcman

 

[bigbillnky]

arcelectric

Morning,
Have you tested the capacitor? A resistance check of the windings is not always a good indicator of their internal condition. A winding analyzer is your best bet.

Just out of curiosity, what is the nameplate HP, RPM, and voltage?

Has this motor been rewound, and possibly the leads have been mis-labeled? Did you follow a connection diagram? If you have ran the motor very long under the conditions you described, it probably is a moot point now.

Bigbillnky,C.E.F.....(Chief Electrical Flunky)

 

[machmech]

"No opens no grounds"= not moot yet!

Capacitor is a good idea. What about switch?

A government which robs Peter to pay Paul
can always depend on the support of Paul.
- George Bernard Shaw

 

[machmech]

Hi Bill

Are you probing for a responsive op? There have been a lot of post and run OPs lately.

I was surprised you did not the question what are the resistance readings you can have readings and still have a toasted winding. They should all be very close to same, correct?

I'll bet this is a fan motor.

Chuck

 

[machmech]

The site is painfully slow.

http://www.lafert.com/products/pdf/New Catalogue 2006 def.pdf