Rotor Voltage

[bob]

Hi,

 

I have got a wound motor rated 1,2 MW 6,6 k V and the open circuit rotor voltage is 1420 V 415 amps. Should the rotor cable rated at 1420 V insulation voltage at least ? Could a standard 1000 V insulated cable be used for this application.

 

Regards.

 

Bob

[marke]

Hello Bob

 

The operating voltage on the rotor circuit will be less than the open circuit voltage except when things go wrong, and that can happen, so it is important that the voltage rating of the cable is adequate for the open circuit voltage.

The open circuit voltage is 1420 volts and that is phase to phase. It would be OK to use single core cables with an insulation voltage of 1000V provided that you could guarantee that one terminal on the rotor din not get connected to earth. As I do not believe that you can guarantee that under fault conditions, it is best to use cores rated for continuous use at 1420 volts.

 

Best regards,