Difference between DLA test and tan delta test for HV motor 1

[krisys]

Difference between DLA test and tan delta test for HV motor

We are intending to perform condition assessment for a 11 kV, 3000 kW motor. Some one has specified two tests, namely

a) Dielectric Loss Angle Test (DLA test)
b) tan delta test

As I understand, functionally these tests are same. Can any one clarify / elaborate further on the difference between these two tests?

 

[edison123]

They are the same.

Muthu

http://www.edison.co.in

 

[krisys]

Thanks Muthu.

Can any other test be carried out as part of the High Voltage motor condition assessment at motor workshop?

 

[edison123]

Full flux loop test for the stator core (ELCID is not good enough)

Tan delta and partial discharge up to the rated voltage (U) as baseline values for future trending

IR and PI (PI > 2)

AC HV test (2U+1 for new winding and 1.5U for part repaired/overhauled winding)

Surge comparison test (2U+1 for new winding and 1.5U for part repaired/overhauled winding)

DC resistance of winding at room temp

No-load run to record no-load current, motor vibrations and bearings stabilization temperatures


Muthu

http://www.edison.co.in

 

[VLFit]

The answers of edison123 are all good. One caveat that should be added is that the AC Withstand test and the TD and PD testing are best performed with power frequency AC high voltage. However, should the capacitance of the load be too high to permit the use of 50/60 Hz. AC voltage, VLF AC 0.1 Hz. voltage can be used. (a 100 lb. VLF hipot can perform the test of a 1000 lb far more expensive and larger, higher power consuming 50/60 Hz. hipot.) A VLF AC hipot and TD and PD diagnostic measurement accessories are readily available. IEEE 433-2009 defines the use of VLF for AC withstand testing rotating machinery. Good luck.

 

[krisys]

Thank you VLFit