water in elec motors

[golfpin]

I apologise in advance because of my idiocy on the PC I am perhaps repeating this post don,t seem to know where to place and then to view it.
So here goes. Have bought a flood damaged Maximat V 10 P lathe. Lathe was completely under water for a few days but after water receded it was never switched on and it stood for about 2 years! Have stripped it, in good shape except of course for the motors, [has milling attachment] stripped the elec. motor, roller bearings siezed but easily replaced but am concerned about the insulation of the windings can this be tested in any way because to get a motor rewound here in RSA is looking for trouble and expense. The on/off for/rev switches, should I flood them with an electrical cleaner and or water dispersant or both I don,t want remove the switches from the panel/mounting box because there are a zillion wires and I am no electrician. Was told that I should place motor in oven to dry out [sounds feasible] not sure of wife though!!! any advice appreciated.
Golfpin

[Harold_V]

Bear in mind, I am not an electrician, nor am I an expert with motors.

Motors can be checked with an instrument called a Megger, and there may be other means. I am not familiar with how they operate, but I believe one of the things they determine is if there's a potential for insulation failure, or if it has already failed.

If the motors have been in a dry place for two years, and have experienced a warm environment, it would be my opinion that they are already dry.
Might not hurt to have someone with experience voice an opinion, though.

Mean time, place an electric heater with a fan on them and allow them to heat up. Can't hurt. The warm, moving air should displace any moisture that may be held within.

Harold

[f350ca]

I haven't had to dry a motor out yet, but read somewhere that placing a low wattage light bulb in series with the motor works well. This reduces the current to the point that the motor can't run and the voltage drop across the motor will be low enough to prevent arcing. It will warm the windings and dry them out. A check with a volt meter from the frame to ground will tell you if the windings are shorting to ground, and a check on the voltage across the bulb will tell you if the windings are shorted to them selves, you should not see full line voltage across the bulb.
Greg

[JHenriksen]

I recently worked on a surface grinder with a motor problem. The cross feed motor was full of oil and would kick out the overload. I took it to my motor winding shop to have him figure out what to do.
He took the motor apart and put the stator in his rotary aqueous parts washer. The detergent wash removed the oil, ( about a 30 minute wash) then he put the stator in his bakeout oven at about400 degrees f for several hours., Everything checked out ok afterwards and the motor is in production.
If you had any concerns of residual water, open the motor up and set it in the sun for a few days, or sneak it in to the kitchen oven. After two years of sitting , it should be ok.

[warmstrong1955]

We used to take wet motors apart, and cook 'em on low in an oven for about 24 hours, leaving the door slightly open.
Worked well with submersible pump motors that lost a seal..... among others.

Our electricians always megged 'em after they were dried. No sense assembling an entire pump if the insulation is shot.

Bill

[golfpin]

To all,
many thanks for the prompt replies I suppose one is caught between a rock and a hard place, trying to sneak said motor into oven or stealing her hairdryer for nef[hair]ous activity,s!!!!!!!
Golfpin

[TomB]

My shop has gone through several floods. Mostly I see the water coming up and I put the motors up higher. For example the motor on my floor mounted vertical bandsaw is about 10" above the floor so I added a plug and socket between the switch and the motor and I take the motor off and set it on the table. But before I had that set up it went under once or twice. Typically I would start the motor and let it run for 30 minutes and all was fine.

But then I had a much bigger flood where the water was 40" rather than 12" deep. All my plans for 15" or less of floods went underwater. I found several types of problems:
1) The bandsaw went back together was run for a bit and all was good.
2) The cabinet table saw (5 hp) was started and ran but then when I pushed the off button nothing happened. I had to unplug it to stop it. When I thought about it and took the switch box apart it was full of water. I let it dry for a bit then reassembled and everything worked.
3) The Shopmaster 3-in-1 has a lathe and mill motor. The lathe motor (about 1 hp) went underwater and would not start. When I took it apart I found the internal start/run switch was corroded (a rivet and spring were dissimilar metals) and I had to replace the spring.
4) The planner motor was well above the water but the switch was submerged. It started fine, ran and stopped, but them several months latter it would not start. I took the switch apart and found it was full of water and corroded. I will need to replace it but have not yet done so as I've not needed the planer.
5) The washing machine motor was a difficult case. It's a new washer and I discovered it runs at 8 or 10 thousand RPM and there is what I presume from the wiring a built-in VFD. Both had to be replaced and the manufactured was absolutely useless with regard to advice. "We can't tell you anything as you are required to call our certified service technicians." Maybe the motor would have run if I replaced the VFD or vise-versa but without advice I just bought both new. On the other hand the dryer started and ran fine.
6) Small power hand tools, drills, sanders etc seem to be either oblivious to the water or destroyed by even dampness. I can't tell why, but if does not run and I take it apart there never seems to be an obvious reason or fix. It is not however possible to get the water out of the plastic boxes they come in.

In my case I deal with clean ground water that comes up through the floor. Flood water from bank overflow or salt water from storm surge would obviously be a different case.

Tom

[hammermill]

depending on the motor , if it has brushes they and the comuntater need to be cleaned. if the lathe has drive eletronics the controls and boards need to be cleaned and brushed then rinsed with deionied water and at leas t dryed

other wise give the bearings a good lube/replace and you should be good to go!

[daGrouch]

+1 for hammermill.

Most damage for electrical/electronics is turning them on while wet. If the power was off the entire time while submerged, the electrical should be ok. 2 years is a lot of drying time. Baking would be needed if the flood were last week.

If the motor core plates are clean or light surface rust only you should be good there too. If they rusted badly, the plates could expand enough to bite into the windings.

Were it my machine I'd hit the switches with contact cleaner, replace bearings and lube, stand back and switch it on with a broomstick.

[lakeside53]

I have had the exact problem with a single phase V10P motor - it was submerged, partially torn down and then left for 10 years...

This motor has no brushes or centrifugal switch so it's easy to "clean out". It's also a two speed motor pretty much "irreplaceable" so handle with care.

-Take it apart (dead easy) - remove nuts/rods and tap the drive end of the shaft with rubber or dead-blow hammer. That will push the rear housing off with shaft.

-Submerge the ROTOR in Evapo rust and use a light scrotch bite pad (white color) to remove any excess. Wash off with hot water.

-Manually clean with scotch brite any rust off the inside of the stator laminations.

-Flush the stator out with clean hot water, then dry it and the rotor in a convection oven or similar at about 175F for several hours. A large cardboard box and a small ceramic heat will work fine also.

- Replace the bearings.

- Reassemble making sure you put the wave washer etc in the correct position. Grease the bell housings bearing retainers.

Here's how I got mine - the previous owner "gave up".


Unfortunately I have to resize the rest of the pictures as this site only allows 800 pixels wide... but you can see them here:

Links :
Cleaned up ready for reassembly with new bearings.
http://i238.photobucket.com/albums/ff15 ... 1Large.jpg


If your worthless Emco switch array is damaged or not working correctly, you can replace it with a couple of toggle switches (assuming single phase).
http://i238.photobucket.com/albums/ff15 ... alRev1.jpg

Physical replacement switch wiring
http://i238.photobucket.com/albums/ff15 ... alRev1.jpg

[golfpin]

Thanks again to all who have chipped in, my current status is that the lathe motor while drying out with low wattage globe up its nose is a bit suspect, the point I think raised by Harold is that the unit might have been switched on some time after the flood will get friend, tame "lecy" very good on our 220 vs your 110 , to come and meg the set up. The mill motor looks as if it might be ok but the meg will hopefully tell the truth.
Thanks again to all, wish we could all get together for a beer or coffee some time some where .
Golfpin ps will continue the saga of rebuild if there is any indicated interest. pps still do not know how to take pics and post, sorry

[golfpin]

Wow lakeside 53 thks your pics they have just come through as I posted, your pics and text describe it all, that is it in a nutshell now time and heat!!!! will tell thks again
Golfpin