Protection of wound rotor induction motors 2

[charlierod]

Hello everybody,

Where could I find guidelines for protecting wound rotor induction motors?

To the best of my knowledge, protection of this type of equipment is achieved in the same manner as for squirrel cage induction motors. But there are still some concerns regarding rotor winding faults for which conventional protection doesn't operate as expected.

Thanks in advance for your help.

 

[electrolitic]

Charlierod
The conventional WR motor protection is achieved in the same manner as for SC induction motor. The problems I had in the past were always related to overheating (even melting) of slip rings(lack of brush pressure, surface wearing, sparkling ). We installed thermal optical sensors inside the brush holder compartment monitoring the slip rings temperature.The present sensors/processors technology can give much more informations (trend graphics, values, etc). This is the best of my knowledge.
Best Regards

 

[charlierod]

Electrolitic,

Thanks for your valuable comment. Could you recommend a manufacturer of these type of sensors?

 

[electrolitic]

charlierod
I don't remember exactly the model we had used but today I consider Raytek compact series CI as an option that must be analysed. ( output J or K or 0 to 5 Volts, 70 deg Celsius ambient temperature, cooling options, 0 to 500 deg Celsius range).
Sorry, I am not familiarized with deg Fahrenheit but It works in both scales.It was a joke. Sorry.
Best Regards