Alterantor rotor heating using DC current
Alterantor rotor heating using DC current
(OP)
Dear All
We have chemical washed an alternator on major overhaul.
Now its rotor is showing very low megger value.
We have tried other heating methods.
Now i want to heat the rotor using DC source.
Can somebody tell me the procedure. We can not run the generator.
Thanks
We have chemical washed an alternator on major overhaul.
Now its rotor is showing very low megger value.
We have tried other heating methods.
Now i want to heat the rotor using DC source.
Can somebody tell me the procedure. We can not run the generator.
Thanks





RE: Alterantor rotor heating using DC current
Yes you could heat the windings with a DC Source like an STATIC WELDING MACHINE(Transformer Type).For Procedure provide more information: What Other Heatings Methods did you try? Slip Ring Type? Brush Less? KVA? Volts? it is dissambled??.Megger Readings??
Regards
Petronila
RE: Alterantor rotor heating using DC current
We have tried Infra red bulbs. Also heaters with blowers.
Its a 18MVA , 11kV alternator. Right now rotor is pulled out of the stator. Megger value is zero.
It is brushless.
Your early reply will be apprecieted.
Aneel
RE: Alterantor rotor heating using DC current
RE: Alterantor rotor heating using DC current
respectfully
RE: Alterantor rotor heating using DC current
Taking account the rotor is pulled out of the stator I will look more than the heating and will check inside of the wires,windings and all rotor“s insulation material in order to find the root cause of this EARTHING .May be the Zero could come like an insulation failure due to winding explosion. You could perform an static test with MCEMAX instrument manufactured by PDMA in order to find short circuits or other failures. I am totally agree with the posted by Skogs in the Same thread No. 237-165089, recommended by EDISON 123: "Conclusion: Not all bad insulation levels can be cured by heating"
Regards,
Petronila
RE: Alterantor rotor heating using DC current
I wouldn't advise DC energising the rotor outside the stator since it is a very powerful magnet and all iron items (screw drivers, spanners, watches etc.) nearby will fly toward to the rotor. Have the rotor inside the stator before you apply DC.
RE: Alterantor rotor heating using DC current
you should "rule out" rotor earth fault.