STANDARD motor repair/rewind specs? 4

[electricpete]

There is a widespread belief among power plant motor engineers I have talked to that detailed specifications are required for repair shop repair/rewind of induction motors. It makes it easier to compare bids among repair shops, helps communicate expectations, and helps guide toward consistent quality.

But those specifications can get large and unwieldly for both the customer and the bidder/repairer. Why should I as a customer re-invent the wheel? And why should each bidder have to spend a lot of time studying my specs.

It seems like the situation would be greatly helped if there were standard repair/rewind specs. Perhaps even a few different levels to convey the difference between level of care/effort expended in handling of a non-motor vs a critical motor.

I haven’t found much out there is this regard. I have seen IEEE1068 (repair/rewind spec for petrochem) and EASA AR100 (available free on the internet). These have some good items but seems like they fall far short of the required level of detail. (particularly AR100 has a lot of qualitative statements not backed by quantitative checks).

I have found a few specs published on the internet… one at eeco-va.com, one from NWIBRT. None of these seems to carry any weight or recognition as a standard.

There are some very good EPRI specs that I rely on heavily. But there are proprietary, not freely available, and not familiar to many motor repair shops.

Any comments? Ideally I would like to hear if there is some big standard spec somewhere that I have missed (I don’t think so). Otherwise… other links to repair specs and recommendations for approaching the problem?

 

[gordonl]

Pete,

I'm not heavily involved in this area, but since so many shops are members of EASA, I would think new standards should be developed and/or published through them, although practically that may be the wrong side of the fence to work from.

 

[GordS]

My approach on this topic has been to leave the busines of motor repair to the repair shops - since they should be the experts. Our repair spec mainly addresses aspects of the repair that are site preferences, such as:
1. Type of grease to install
2. Format of and information expected in the repair report.
3. Tests we expect to be performed on the completed repair along with acceptance criteria.
4. How do we do business with the shop ( ie, contacts, paperflow, authorization to proceed with repair, etc)
5. When do we insist on VPI treatment.
to name a few.

A very small portion of the spec specifies actual repair practices. Those few instances are based on instances that have bitten us in the past so we have deemed important enough to highlight to the repair shop.

We have the capability in our spec to attach a detailed repair spec if we have one. This is more likely to happen with larger motors.

 

[jbartos]

Suggestion: Specs may be created from a suitable literature. Visit

http://www.oit.doe.gov/bestpractices/pdfs/biblio.pdf

for related literature

 

[advidana]

Bidding is not a good idea. Repair of a motor is like a repair on your car engine- It's the wild west out there. I would get the best repair shop in your area to repair your motor. Then have them comply with your spec.

You cannot not specify quality into any repair.

I agree, there are a lot of spec's out there, some are good and some are just ok. I think experience will sort them out.

Good Luck

 

[jbartos]

Suggestion: I agree with the previous posting about difficulties to obtain a good quality product. Normally, a product quality is ascertained by the product factory test and certification that may include the product test results. Such products are considered to be "good quality" products. They are often sought. I was looking for Mean Time Between Failure (MBTF) and Mean Time To Repair (MTTR) for motor speed drives at motor drive manufacturers. Out of a few major ones contacted the result was:
First provided a number based on a reliability software analysis
Second one gave me an empirical estimate (based how many complaints and repairs arrived).
Third one got very irritated about such a nuisance as MTBF and MTTR
Others said: Either it was in the preparation or not available.

 

[electricpete]

advidana - I agree with you that attempting to spec quality is close to impossilbe... much better to pick a good repair shop. But there are still one big issue:

the bid process is a necessary fact of life in a large company. As an engineer I cannot tell our procurement people which repair shop to go to. I can create the specs and provide input to selecting the bidders and evaluting the bids. At least that's what we're stuck with now.

 

[edison123]

pete,

If you want, I could mail you the various specs and tests that we follow in our shop.

 

[electricpete]

Kumar - that would be great.

Can you please send it to the address in my profile?

Thanks
Pete

 

[electricpete]

Sorry, I meant Agoram, not Kumar.

 

[edison123]

pete,

did you get my mail ?