Flooded motor

[Patrick Kane]

This is a bit of a freak accident, but i dropped off a 3 phase motor at my local shop for the drive shaft bearing to be changed and a general refurb since it was from '65. Just got the call today that he had a foot of water in his shop, and the motor got flooded. He took it to the larger shop in town for them t bake the motor and dry out the windings, but now im wondering if this motor is worth $200-300 to be worked on? Without having power to the unit, is moisture exposure a bad thing? Frankly, i dont know enough to know if lasting harm was done or not.

[Darcy Warner]

If it was under water for years, maybe. In this situation I see no ill effect.

[John K Jordan]

This is a bit of a freak accident, but i dropped off a 3 phase motor at my local shop for the drive shaft bearing to be changed and a general refurb since it was from '65. Just got the call today that he had a foot of water in his shop, and the motor got flooded. He took it to the larger shop in town for them t bake the motor and dry out the windings, but now im wondering if this motor is worth $200-300 to be worked on? Without having power to the unit, is moisture exposure a bad thing? Frankly, i dont know enough to know if lasting harm was done or not.

I see a info on the web about drying motors. This may interest you:
https://www.schneider-electric.us/en...wet-motors.jsp

JKJ

[Patrick Kane]

Ok, the internal caveman in me thought, water in motor no good, but then after consider it a minute most damage occurs when stuff is wet and there is a power source connected. Electronics being the thing i know a little something about with power and moisture. My brother is a wizard at falling in streams and miraculously saving wet phones.

What the small shop was going to do for $150-200 is now looking like $300-350, which sucks a bit, but my hands are kinda tied on it now. Ordered the VFD last week and it will be here today. Full swap to single phase looks like it would have been the cheaper route now. Thanks for the info, i was having a lot of second thoughts about frantically calling the shop back to stop the presses on doing any work on the thing.

[Peter Kuhlman]

As long as it was fresh water you are probably fine. If salt water I wouldn’t bother repairing it based upon all the motors we had repaired after a major hurricane. Most failed within a year of being redone.

[Darcy Warner]

I don't see why you need to pay for the extra work needed because they had water in their shop.

[Dan Friedrichs]

What exactly are they doing for this cost? A 3 phase motor has very few parts: rotor, bearings, stator, windings. They aren't re-winding it, I assume. So they're replacing 2 bearings (cost: $10)?

I'd ask for a detailed bill...

[Patrick Kane]

Oh yeah, the extra cost is associated with the big shop working on it with a considerably higher labor charge(specifically the labor charge i was looking to avoid by going to the small shop in the first place). I can have this guy do the work for the original estimate, but i would be sitting around waiting for a month and a half since his shop is inoperable for the moment. However, im hesitant to take it back now, because i have no freaking clue how to treat a wet motor. Also dont want to be sitting on a lame duck saw for two months.

[Darcy Warner]

Oh yeah, the extra cost is associated with the big shop working on it with a considerably higher labor charge(specifically the labor charge i was looking to avoid by going to the small shop in the first place). I can have this guy do the work for the original estimate, but i would be sitting around waiting for a month and a half since his shop is inoperable for the moment. However, im hesitant to take it back now, because i have no freaking clue how to treat a wet motor. Also dont want to be sitting on a lame duck saw for two months.

Bearing change in a motor is so easy.

Put it in the oven for a few hours.

[Frank Pratt]

New bearings, a bake in the oven, then to a hi-pot test to make sure all the insulation is still good.

[Dan Friedrichs]

Still...changing bearings is maybe a 20 minute job.

[Charles Lent]

I was once the North American Electrical Factory Rep for a European Printing Press Manufacturer. Several of our customers in the US got flooded and called for help to get their presses back in business. I pulled the motors and transformers that had been under water and had a local motor shop rinse and bake them, replace the bearings, and hi pot test them. I had the presses back running in 4 days, but these were fresh water floods and the local motor shop was able to provide the help needed promptly. None of the motors or transformers failed later, at least for the remaining years that I still had that job. If these were salt water floods, I doubt that I would have been as successful, but I would have started the recovery with a very thorough fresh water rinse before baking them. The hi pot test should tell you if the insulation is OK before you put it back into service.

The place that had your motor should have insurance to cover the costs of recovery or replacement, and the motor shop that bakes and hi pots them should be able to provide some guarantee that they are acceptable. I would start there.

Charley

[Bill Dufour]

They need to slowly dry them out and replace the bearings. Too quick a heating can cause steam which seems like it could blow windings apart. If this is under 10Hp I would bake in an oven at around 200f for a few days then dip and bake. For a big generator my Neighbor says it took him about six months.
They built a vacuum chamber around each generator with electric heaters inside. They keep the temp just below boiling water. After a while the vacuum would hold for a while when the pumps were turned off showing that most of the water had evaporated. he said they enclosures where never good enough to not leak at all. His method worked good enough that he was called in special when the next flood hit the river and took out another states generators.
He enjoyed the work but not enough to go until the federal government said he had to go.
Bill D.