10 MW synchronous generator cleaning
10 MW synchronous generator cleaning
(OP)
Dear All experts,
we have 10 MW 6600 volt synchronous generator, Lube oil was leaking inside the generator from DE bearing which cause a dirty winding as the attached photo.
we make megger test (5 KVdc - 1 min )all readings was good and more than 2G ohm.
I am wondering ,what is the effect of operating the generator in this case ?
How can we clean without dismantling the generator ? We do not have the ability to pull up the rotor shaft from the stator.
which solvent we can use ?
thanks in advance
we have 10 MW 6600 volt synchronous generator, Lube oil was leaking inside the generator from DE bearing which cause a dirty winding as the attached photo.
we make megger test (5 KVdc - 1 min )all readings was good and more than 2G ohm.
I am wondering ,what is the effect of operating the generator in this case ?
How can we clean without dismantling the generator ? We do not have the ability to pull up the rotor shaft from the stator.
which solvent we can use ?
thanks in advance
RE: 10 MW synchronous generator cleaning
Muthu
www.edison.co.in
RE: 10 MW synchronous generator cleaning
Itsmoked taught me this. Thanks Keith.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: 10 MW synchronous generator cleaning
Muthu
www.edison.co.in
RE: 10 MW synchronous generator cleaning
Chapter 25, Rotating Equipment recommends using a cleaning solvent.
Alstrom generator maintenance manual recommends using "white spirit" (Yep, turpentine - paint thinner). And don't let the solvent soak into the windings.
Most of the techs I work with like CRC Electro-Clean. After a wipe down (as recommended by Edison and Bill, they will get a case of the CRC, spray, wipe, meg after dried.
Considering the capital investment was $10M - $20M, I highly recommend getting out the mfg maintenance manual and following their recommended procedure - really, that first.
All the maintenance specs say oil contamination degrades the insulation. It needs to be cleaned up.
Personal opinion:
As said, wipe up all you can.
Spray solvent and wipe the rest.
Thoroughly dry and meg before putting into service
the worm
Harmless flakes working together can unleash an avalanche of destruction
RE: 10 MW synchronous generator cleaning
Was this one the one that was rewound in 2016?
Harmless flakes working together can unleash an avalanche of destruction
RE: 10 MW synchronous generator cleaning
then it is not really that dirty when compared with how bad it could be.
If globs of debris obstructed the voids between the form wound coils,
then yes... the dirt would be prohibiting free air flow.
Because it's not possible to take the motor out of service for proper cleaning,
the first one can do is as edison123 suggests. Mop up, wipe off, CLEAN off
debris as best as can be accomplished.
It's going to take a LOT of clean rags that will become dirty real fast.
And as other's have suggested, it's not a good idea to use any solvents or liquid(s)
of any kind... because there is no adequate means of thoroughly drying out the winding after getting it wet.
CRC Electro-Clean could certainly be used as suggested by iceworm.
You'll need a couple three cases of it however to get you started based on how
dirty the winding appears to be.
If the apparatus was removed for cleaning... then of course any of the typical
cleaning methods using old fashioned soap and water applied under moderate
pressure... then dried out... and cleaned again if need be... and dried out once again
would be the usual cleaning steps.
Ice blasting would be another approach... but confirmation that the process is not leaving
moisture in hidden voids would have to be determined.
A lot of CLEAN rags. A lot of WIPING off the debris. Cases of CRC Electro-Clean
(or equivalent ; )
And, a plan on when the machine can be scheduled for proper cleaning.
John
RE: 10 MW synchronous generator cleaning
I'm curious - have you ever heard of an oil motor winding catching fire?
=====================================
(2B)+(2B)' ?
RE: 10 MW synchronous generator cleaning
RE: 10 MW synchronous generator cleaning
When the winding flashes over, oil/grease flash points are easily achieved.
Unattended accumulated oil from the engine caused this fire damage in a DG alternator stator.
With collateral damages to the rotor and exciter.
Sorry about the white spaces, don't know how to fix it.
Muthu
www.edison.co.in
RE: 10 MW synchronous generator cleaning
RE: 10 MW synchronous generator cleaning
manufacture manual" Oil and grease are not harmful to insulation but they do accumulate dust. Remove oil
or grease with a cloth moistened, but not dripping, with a safety type, commercial
cleaning solvent. "
i am seeking for suitable solvent and not effeect on winding insulation
RE: 10 MW synchronous generator cleaning
Dab a small amount of white spirit on the soft cloth and wipe away those hard to reach points with a stick. Good luck with that.
The cloth should not be dripping with the solvent. Otherwise, you will simply wash down that hard to reach dirt making it a harder to reach dirt.
Muthu
www.edison.co.in
RE: 10 MW synchronous generator cleaning
It does strike me that there are many many oily motors in plants and repair shops that aren't generally considered as fire hazards (I admit that's a vague term). Maybe they should be.
=====================================
(2B)+(2B)' ?