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Generator Testing

05/11/2017 11:14 AM

the packing sheet of a 20KV,15MW generator caught fire while being transported .the fire was extenguished within 15 minutes .however terminal boxes and end shields caused some fire to enter stator (only staror was being transported).now i want to know want kind of tests are needed to ascertain the integrity of stator winding , core laminations,space heater ,winding temperature sensors etc. as i know that insulation life is reduced for each 10 degree rise in temp above nominal temp.so how to account for this due to fire temp.

regards,

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#1

Re: Generator Testing

05/11/2017 11:53 AM

You don't. You contact the manufacturer of the stator and have them evaluate it.

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#2
In reply to #1

Re: Generator Testing

05/11/2017 1:03 PM

we cant send it back because of some contractual obligation.the only reference i got is throgh IEC 60034-18 ,which gives methods for functional evaluation of insulation system.i am not sure if this standard covers all possibile tests for our problem fact finding.

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#4
In reply to #2

Re: Generator Testing

05/11/2017 2:45 PM

If you all can't send it back then you've only got two options. Either call out the manufacturer's representative, or scrap it and buy another one.

If you think you can do a better job on it without involving the manufacturer, then why the heck are you coming here?

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#24
In reply to #2

Re: Generator Testing

05/13/2017 12:22 AM

"we cant send it back because of some contractual obligation"

What sort of 'contractual obligation' would require you to accept delivery of damaged goods?

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#25
In reply to #24

Re: Generator Testing

05/13/2017 8:21 AM

Purchased used as is where is you haul away.

That type of contract.

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#26
In reply to #25

Re: Generator Testing

05/13/2017 8:31 AM

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#3

Re: Generator Testing

05/11/2017 1:17 PM

There is no possible condition that would force me to put this unit into operation.

As an AHJ, I would not allow this unit to be placed in service without a document from the OEM saying that the unit is good to go.

If the OEM cannot certify it for some reason or the other, go after the carrier that was transporting this unit for damages and get a new one.

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#6
In reply to #3

Re: Generator Testing

05/11/2017 3:49 PM

Agreed.

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#8
In reply to #3

Re: Generator Testing

05/11/2017 4:34 PM

Except if ol' coolyaar was anywhere near this during transport, and threw out his lit cigar, I would be willing to place odds. Where in heck did he steal a generator that size without getting caught, anyhow? That's a joke, if anyone is interested.

Another question: Was this second-hand purchase contract agreement/obligation?

Third-party purchase? Were the shipping arrangements for delivered price from OEM, or delivered from seller, or was it F.O.B. OEM shop?

As an AHJ, you are absolutely correct in what you are saying, and coolyaar would do well to listen to you, and there is no way he can assume the responsibility and risk of energizing that system if the rotor insulation is compromised in any way, not to mention the instrumentation, etc.

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#15
In reply to #3

Re: Generator Testing

05/11/2017 10:35 PM

They don’t have AHJ’s in Sri Lanka, they work to a form of BS7671 which he obviously still hasn’t bought yet.

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#5

Re: Generator Testing

05/11/2017 3:47 PM

It is likely damaged. Contact your appropriate insurance provider and make a claim! This is EXACTLY why you have insurance.

If you don't have insurance (which really wouldn't surprise me at all at this point) send it back to the manufacturer or a local qualified service agent for inspection, repair and test. Pay money to have it done if they wont do it for free.

You won't be able to test it yourself, you wont be able to repair it yourself, you won't be able to calculate the expected life or extent of the damage yourself.

What the hell, throw it in the generator and turn it on and see what happens. Based on your previous posts have your clueless boss stand next to it when you throw the breaker, I am sure he won't mind.

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#9
In reply to #5

Re: Generator Testing

05/11/2017 4:36 PM

He could also (coolyaar that is), tell his boss the generator is "sick", and to lay hands upon it, for that surely will make it better.

If they were to hold hands during the spin up ceremony, so much the better, not.

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#12
In reply to #9

Re: Generator Testing

05/11/2017 5:27 PM

hahaha.good one

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#7

Re: Generator Testing

05/11/2017 3:49 PM

You may also request your generator vendor use a different carrier next time, one that doesn't set its deliveries on fire?

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#10

Re: Generator Testing

05/11/2017 4:43 PM

This is obviously some​ kind of joke.

Am I the only one who doesn't find it funny?

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#11
In reply to #10

Re: Generator Testing

05/11/2017 4:49 PM

I am not sure coolyaar realizes that carbon conducts electricity. There is no way to light this thing up without literally lighting it up! It is well done, toasted, fried, whatever, over and out.

Coolyaar may in fact, be the unluckiest fellow on our forum to ever appear.

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#13
In reply to #10

Re: Generator Testing

05/11/2017 6:05 PM

Mildred said you'd say that.

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#14

Re: Generator Testing

05/11/2017 7:59 PM

Excuse me.... Can someone sign for this delivery?

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#20
In reply to #14

Re: Generator Testing

05/12/2017 3:31 AM

OK!

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#16

Re: Generator Testing

05/11/2017 11:05 PM

Given you have no way out on this if it was me I would be taking a detailed look at what exactly got damaged in the windings.

Given its a 20 KV unit those windings are likely going to have a substantial amount of insulation covering them of which if you got lucky only the outermost layer got scorched.

Years ago I worked at the big coal mine here in North Dakota as a student co-op employ ona work and learn program. I worked with the electrical crews and was around the HV power systems they used all the time ranging from 4160 to 23KV system voltages.

As a student peon I got put on the menial task work a lot of which repairing various HV devices and cabling and HV control units was two of the main things I did.

Anyway, with the higher voltage stuff pretty much everything used multi layer insulations made of various materials ranging from rubbers to fiberglass and epoxy compounds depending on the application.

Given that I would be tempted to do a bit of exploratory surgery on the damage insulation and see just how deep it was burned. If it's just a top protective layer you may actually be good to go with minimal repair work.

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#17
In reply to #16

Re: Generator Testing

05/12/2017 12:01 AM

Now don't go encourage him to half-ass it.

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#21
In reply to #17

Re: Generator Testing

05/12/2017 1:06 PM

When presented with such scenarios where the only option beyond attempting to repair something myself is to scrap it I tend to give the exploratory surgery and repair route a try before I junk something.

If the attempted repair works I got what I needed and if it didn't I learned something from the experience.

Either way I at least tried to do something about the problem besides throw it away and start over not knowing anything new.

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#22
In reply to #21

Re: Generator Testing

05/12/2017 2:43 PM

Yes... but...

We are talking about a 20KV 15MW stator that got roasted for 15 minutes.

Would you want that running in your facility after someone "explored" a tad?

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#23
In reply to #22

Re: Generator Testing

05/12/2017 8:34 PM

If it was my facility and it passed any reasonable post repair testing I could come up with, that should be a normal routine annual or specific run time preventative maintenance test procedure, Heck yes!

It was designed by a human and built by a human therefore with proper technical diligence it can be repaired by a human.

If one cannot trust their own workmanship they should not be in business period.

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#27
In reply to #23

Re: Generator Testing

05/13/2017 8:50 AM

that is what i am talking about.there must be some set of tests to pinpoint the extent of damage and then apply suitable repair measurs. at least one should give a trying.this is the way how people learn things instead of just calling manufacturers.

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#28
In reply to #27

Re: Generator Testing

05/13/2017 8:55 AM

Are you willing to sit on the thing when they crank it up? You know, to demonstrate your confidence in the repair? We're only talking 20 kV, right? No biggie should the insulation fail?

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#29
In reply to #28

Re: Generator Testing

05/13/2017 10:13 AM

Why would he be sitting on it?

More than likely he and everyone else involved in the installation would be standing a reasonable distance away (in a control room perhaps) just in case the repair didn't go as well as hoped.

Also it's a electrical generator not a nuclear reactor so even if it does fail all they get to see is a impressive fireworks show for a moment while the system shuts down.

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#34
In reply to #28

Re: Generator Testing

05/15/2017 11:52 AM

Do people sit on new one when they crank it up?

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#35
In reply to #34

Re: Generator Testing

05/15/2017 11:54 AM

Some prefer to stand. You planning to get a new one because that stator is screwed.

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#37
In reply to #35

Re: Generator Testing

05/16/2017 10:14 AM

I can expect only you sit on it. One advice! Sit "tight"

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#38
In reply to #35

Re: Generator Testing

05/16/2017 10:49 AM

I think Mr. coolyaar was attempting to be phunny and invite to the grand re-opening of his 20 MW machine, although, I personally would want a wee bit more distance between me and the machine during start up, sync idle, and latch in. I give it about 30 ms after latch in, just to be generous.

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#30
In reply to #27

Re: Generator Testing

05/13/2017 10:29 AM

That's where you have to make the decision whether you are willing to give repairing it yourself a try or spending the money to have someone else work on it for you.

Until you make the effort to determine what degree of damage it sustained you will have no way of knowing what is the next and most appropriate step to repair it.

The way I see it right now you have very little to loose in taking some time and exploring the actual damage to see what may or may not need to be done.

No one here can make that decision for you.

Personally I pick up equipment all the time that people don't want mostly because they see some cosmetic or minor damage as being proof the item is junk yet the reality is far from it.

In fact I have thread about it here right now. The things people throw away.

Recently I got a perfectly good $400 impact gun for free that took all of $12 and 15 minutes of my time to fix that someone threw out because they feel was 'unrepairable'.

After that I got a good pickup truck for cheap for the same reasons. Someone didn't feel that spending a few hundred dollars and half a day of their time was worth it to keep a good vehicle (their only vehicle they really need and can't afford to replace) on the road.

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#31
In reply to #27

Re: Generator Testing

05/14/2017 10:59 AM

Sure, "just" clean off as much residue as possible, run the same series of tests that were performed during its manufacture and FAT (Factory Acceptance Test), and compare the results.

You really should include some pictures showing the extent of the damage. You could be making the mistake of looking at the insulation when in fact if the core laminations were severely overheated then you'll need to rebuild the entire stator.

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#36
In reply to #31

Re: Generator Testing

05/15/2017 1:31 PM

I would be willing to bet that no matter what you do to it, as far as cleaning/repairs, it will never pass the "Megger" test. Incident 1 - coolyaar 0.

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#32
In reply to #27

Re: Generator Testing

05/14/2017 3:40 PM

Perhaps I should elaborate. Based on your previous posts I am not confident you should try as I don't believe you have the necessary education and training to perform such a delicate and dangerous job.

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#33
In reply to #21

Re: Generator Testing

05/14/2017 3:42 PM

Who said anything about you and what you are capable of? See post #32. Serious safety concerns and all.

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#18

Re: Generator Testing

05/12/2017 12:08 AM

You might try the Meyers-Briggs and the Peters Delusion Inventory tests, then consult the DSM-IV-TR criteria for further evaluation. Should the problem persist, layering with risperidone, quetiapine, and olanzipine may help; however, in extreme cases a mixture of haloperidol and lorazepam may be necessary. When all else fails try using a Skinner Box to dispense the bad news.

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#19
In reply to #18

Re: Generator Testing

05/12/2017 1:22 AM

roflmaopmsl

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