wound rotor 8/4 poles

[bum2]

Hello. We have a Chinese-made motor with a wound rotor YZRDW250M-8/4 30 kW under repair. The rotor was rewound, the stator has a factory winding. Please help connect the rotor winding. As I understand it, the rotor winding is 8 poles, when operating at 750 rpm, the rings close, and when operating at 1500 rpm, the rings open. At 750 rpm (with closed rings), it works fine for us, but at 1500 rpm (with open rings), there is no rotation, the rotor can be turned by hand at the rated voltage on the stator. Thank you very much in advance for your answers

 

[jraef]

Rings opening and closing is not a WRIM... If the ring circuit opens, the motor wouldn't work. Or are you talking about SHORTING the rings?

Are you sure this isn't a Repulsion / Induction motor? That's a really old, kind of forgotten technology though, I don't know why anyone would resurrect it...

 

[waross]

Good call on the induction repulsion motor, Jeff.
There should be a shorting bracelet that shorts the commutator when the brushes are lifted.
If the bracelet is not moving into the proper position the motor will stall.
Or;
A two speed WRIM?
Possible I guess.
The two speeds will be wound on the stator.
The rotor will need either a short or resistors on the slip rings at either speed.