Synchronoun Motor Fluctuating

[alhafeedh]

We have HP & MP 15MW injuction synchronous motors the MP with voith coupling start fluctuating during loading 55% of its running load, the motor PF and load current fluctuate and tripped on rotor earth fualt. all excitation circuit tested and found okay.
this is the second time any help?

 

[CouplingGuru]

Could you take a picture of the coupling? Not sure if you have a Fluid coupling for soft start or something different.

When it comes to couplings we are always here to help.

http://WWW.PSCCOUPLINGS.COM