Motor failure

[powerjunx]

Due to maintenance upgrades and revision, i was assign to evaluate and record all motor failures in our plant, though i have undergone failure analysis before...

I would like to ask you for a Copy of "Standard Checklist format" of the so called Root-Cause Failure Analysis.


All comments is highly appreciated!!



Big Thanks!!

 

[electricpete]

We don't have a standard checklist, but I think the following data would be a good start to analyse an electrical fault:

At the plant:
Which protective relay tripped
Megger reading and bridge readings. (separate phases for megger readings if possible).
Weather conditions at time of the trip.
System operation at time of the trip (starting,steady state, etc).
Any visual observations

At the shop:
Repeat megger and bridge.
Disassemble, remove rotor, perform visual inspection. Note any abnormal conditions.
Determine location of any ground (abnormal megger) and turn (abnormal bridge) faults based on both visual (if possible) and electrical (successively isolating portions of the coil).
Note the electrical location of the failure in relation to line end coil. (suggests possible surge or partial discharge induced degradation)
Note the physical location of the failure in relation to vent ducts (suggests possible moisture)
Isolate the faulty coils. If rewind is planned, test remaining coils to destruction by surge and/or hi-pot to assess the health of remaining coils (is there a general weakness or just a fault in the one coil).
General visual inspection of the stator for partial discharge, evidence of end-turn movement (loose blocking, cracked coatings), wedge tightness, etc.


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[powerjunx]

Pete, i appreciate your comment.

I did quite similar fault analysis as yours, but the sad thing is... my boss wants a universally accepted format.

I hate to argue with him that is why i had this inniative to search in this forum.

 

[edison123]

What pete has given is pretty much I use at my shop. Since I am in India and pete is from US, you could call this universal ???

As far as I know, there ain't any universally accepted maintenance format.

Tell your boss that there ain't anything in this world that is failure-proof. All things will fail when they age (which again depends on how you use or abuse them)

* How do centenarians handle peer pressure ? *

 

[powerjunx]

ed,

i think you're right - pointing out you're practice as universal.

But i never meant about a maintenance format and i know maintenance varies to every plant, etc.

i'm after of the Root Cause checklist format.

I notice and heard about Failure Analysis but can't find a good link on the web, could you please direct me to such site?



Regards..

 

[GGOSS]

Hello fbcybil,

For general information and photographic images of startor failures you could try the following;

Go to:

http://www.easa.com

Click on: Industry Info
Click on: Failures in Three-Phase Stator Windings

It may not be the 'be all and end all' but it's certainly a good starting place.

Regards,
GGOSS