MV Motor maintenance
MV Motor maintenance
(OP)
Hi,
We have on site one 4,0 MW 11 k V wound motor which has been operating well since installation two years ago.The insurance company is now pushing us to overhaul the motor for bearing and winding inspections.We have contacted the motor manufacturer and they said that this decison should be taken by the client!!
We are planning to effect a non-destructive analysis of the winding of the motor by a third company. The test will evaluate the insulation condition for winding contamination. This test will also determine early winding defects ( for a new installed motor ). In addition, we are also planning to contract a third party to effect an analysis of the bearings on the motor notwithstanding the fact that we have on-line vibration measurements on both drive and non-drive ends.
I am afraid the insurance company would still stick to the stupid idea of overhauling. I am looking for IEC or NEMA maintenance recommendations for a motor of this size. Thanks for any input.
Grundig
We have on site one 4,0 MW 11 k V wound motor which has been operating well since installation two years ago.The insurance company is now pushing us to overhaul the motor for bearing and winding inspections.We have contacted the motor manufacturer and they said that this decison should be taken by the client!!
We are planning to effect a non-destructive analysis of the winding of the motor by a third company. The test will evaluate the insulation condition for winding contamination. This test will also determine early winding defects ( for a new installed motor ). In addition, we are also planning to contract a third party to effect an analysis of the bearings on the motor notwithstanding the fact that we have on-line vibration measurements on both drive and non-drive ends.
I am afraid the insurance company would still stick to the stupid idea of overhauling. I am looking for IEC or NEMA maintenance recommendations for a motor of this size. Thanks for any input.
Grundig





RE: MV Motor maintenance
1. Contaminated environment inside the motor.
2. Abnormal winding and bearing temps.
3. Abnormal noise
4. Abnormal vibration
5. Low IR values (Trending)
6. Abnormal currents
As a motor repair man, I am not aware of any standards about scheduling of motor overhauls.
And insurance company is definitely not the reason to do it especially if the motor has been running well. There is always a possibility that you screw up during the "overhaul" and spoil a well-running motor.
My 0.02 $
* Women are like the police. They can have all the evidence in the world and yet they still want a confession - Chris Rock *
RE: MV Motor maintenance
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RE: MV Motor maintenance
Grundig
RE: MV Motor maintenance
Grundig
RE: MV Motor maintenance
You can kick the ball back at them by asking them if they can show any standard for their claim and if they are willing to foot the bill for the "overhaul" and any consequential damages.
I too hate the bean counters.
* Women are like the police. They can have all the evidence in the world and yet they still want a confession - Chris Rock *
RE: MV Motor maintenance
Here is something else with a discussion of intefval (seems very agressive to me).
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RE: MV Motor maintenance
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Eng-tips forums: The best place on the web for engineering discussions.
RE: MV Motor maintenance
Our most agressive interval for motor refurbishment is 10 years. We have some motors 15 years, some 20 years, and many not at all.
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RE: MV Motor maintenance
Also, is this a batch process or continuous operation?
You can install a partial discharge monitoring system at this voltage to get a decent indicator of insualtion health online. This, coupled with your vibration monitoring system and temperature monitoring would tell almost everything you need to determine what maintenance is required and when.
RE: MV Motor maintenance
What are the works you would cover under refurbishment ?
Would motor refurbishment also include rewind ?
* Women are like the police. They can have all the evidence in the world and yet they still want a confession - Chris Rock *
RE: MV Motor maintenance
Grundig - If this is a horizontal motor, you can usually do half of this scope in-place with only 10% of the effort: pull the end-covers, inspect end-windings, clean them with dry ice, support rotor, roll out bearings for inspection, reassemble, test. If you get to negotiating with your insurance carrier, this may be something they would accept instead.
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Eng-tips forums: The best place on the web for engineering discussions.
RE: MV Motor maintenance
* Women are like the police. They can have all the evidence in the world and yet they still want a confession - Chris Rock *