Requirement of Loss Tangent or tan (delta) test for 11kV 3MW motor during the commissioning

[krisys]

Good day,

We are going to commission two (2) nos. of 11kV, 3MW motors at our facilities. The motor is also having an explosion proof enclosure, IEC type Ex "d". I would like to know, whether I should insist on Loss Tangent or tan (delta) test as a commissioning test?

The initial tan (delta) test results are the very useful reference (signature) for the subsequent tan (delta)tests in case required during the life time of the motor.

Sharing your views and experience is appreciated.

Thanks in advance.

 

[krisys]

Please read the above query with "partial discharge test (PD)" instead of "tan (delta) test"

 

[edison123]

If FAT was done with these both tests, that should be good enough for the baseline.

Muthu

http://www.edison.co.in

 

[ScottyUK]

I suggest that the PD test is essential for an 11kV machine.

You might want to consider getting Rogowski coils or RF CTs fitted to the machine and the secondaries brought out to an external terminal box by the factory. Field modifications to an Ex'd' machine will run into all sorts of certification problems. The cost should be fairly trivial in the overall scheme of things.

 

[krisys]

Today I have verified at site and found that the PD Sensor connection is brought to a separate auxiliary terminal box. Hence, it should be possible to perform the measurement easily.