VFDS ON WOUND ROTOR MOTORS

[EJP21]

Has anybody seen these motors run ok on vfds and how do you calculate the resistors across the brushs.

Thanks
Ed

 

[ctolbert]

Ed:

There was a lengthy discussion on this topic a while back.

thread237-7851 a search on vfd's if this link doesn't work.

Carl

 

[Marke]

Because you are not going to operate the motor under a high slip condition, you simply short out the rotor windings. This can be done on the rotor itself and the brushgear removed. No resistors are required. Mark Empson

http://www.lmphotonics.com

 

[Chris33]

Marke is right. All you have to do is short the rotor windings. Take out the brush gear and short the rings. The best way to do this is to get two pieces of copper bar and put them 180 degrees apart so that the rotor is balanced.