Thread: drying a motor

Hi guys,
as a fill in job I decided to clean the electric motor for the power hacksaw. I pulled it apart and cleaned the ends and the suds pump.
I am down to the windings now but am not sure if I should use the pressure washer and degreaser as the windings have oil in them.
The real problem is drying it later. I vaguely remember other members putting theirs in the oven although I may be wrong.
I'm not quite sure of the correct procedure.
Any help would be appreciated.

Phil
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Hi Phil,

On a day like today, just leaving it in the sun would probably do.

Normal procedure is bake in a moderate oven with potatoes and carrots until golden brown, and serve with 3 phase 415 or 240 depending on taste.

Ray

PS. At the SIL's work when they do a rewind, it's a varnish dip first and then into the oven to bake

Originally Posted by Steamwhisperer

Hi guys,
as a fill in job I decided to clean the electric motor for the power hacksaw. I pulled it apart and cleaned the ends and the suds pump.
I am down to the windings now but am not sure if I should use the pressure washer and degreaser as the windings have oil in them.
The real problem is drying it later. I vaguely remember other members putting theirs in the oven although I may be wrong.
I'm not quite sure of the correct procedure.
Any help would be appreciated.

Phil
DSCN1240.jpg DSCN1248.jpg DSCN1261.jpg

Wash it out, dry in an oven at about 80*

Leaving it in the sun works well or put it in the oven on VERY low heat ie 40°C or put it front of a fan for a few hours.

Originally Posted by Steamwhisperer

Hi guys,
as a fill in job I decided to clean the electric motor for the power hacksaw. I pulled it apart and cleaned the ends and the suds pump.
I am down to the windings now but am not sure if I should use the pressure washer and degreaser as the windings have oil in them.
The real problem is drying it later. I vaguely remember other members putting theirs in the oven although I may be wrong.
I'm not quite sure of the correct procedure.
Any help would be appreciated.

Phil
DSCN1240.jpg DSCN1248.jpg DSCN1261.jpg

Definitely needs to be dried. Water in the windings can cause a short circuit with expensive results. My 25HP air compressor motor is in the shop for a rewind ATM though that was apparently mechanical damage not water. The previous owner was a total idiot WRT maintenance etc, the amount of debris inside the housing had to be seen to be believed. A very expensive lesson in not inspecting it earlier- I'd moved the thing to its new home and I suspect that I disturbed something because 30 seconds or less after pushing the button there was a nice flame flash, lots of brown smoke and...... silence.

The only good part of it is, I now know without any doubt that the circuit breakers work as designed.

PDW

Phil, I would be inclined to use a bit of petrol, provided there is nothing in there that will be effected. Just do it outside and away from sparks, and it will dry very quickly. The insulation coating on the windings should be impervious to petrol, provided it is not in there too long. And it seems that most of the junk is in the main shell of the motor.

Regards,

John.

For stuff that might be too big or heavy go into a domestic oven I found a judiciously aimed hair drier set on low works pretty well.

If you had a decent heat gun you could make up a box for the motor and just blow some air through. (Perhaps do some thing similar with fan heater)

Michael

Originally Posted by Michael G

If you had a decent heat gun you could make up a box for the motor and just blow some air through. (Perhaps do some thing similar with fan heater)

Michael

Hi Michael,

That's exactly what I have for drying electronics, its a fan heater ( one of the ones with on/off temperature control ) mounted in a box, and drying rack.

When de-fluxing printed circuit boards, I use a water based flux remover (safe wash) , and rinse the boards in running water, then into the drying cabinet for a few hours, generally run at about 70C,

For a motor, I'd keep the temp down to 70 or 80C.. and leave it with air circulating for 4 or 5 hours. The pressure washer is bound to push water into small crevices and hard to get spots. So the longer the better.

Ideally you would then megger test the windings, but I don't think Phil has a megger?

Ray

I have used mineral turps because I'm to cheap to use the proper lectra clean spray and the internet told me it was more or less the same.... It worked fine. I would be a little reluctant to use water or a harsher solvent but they may well work ok, but I definetely wouldn't pressure wash it! You need to avoid anything that could damage the varnish either mechanically or chemically.

Anyway its a vented motor so I wouldn't be too hung up about getting it spotless... just wash the lumpy bits out and youre good.

Originally Posted by RayG

Ideally you would then megger test the windings, but I don't think Phil has a megger?

I may be able to lend Phil my cheap Chinese (ebay) megger. When I bought my Mill I asked the question of myself - "Is it worth $35 to guard against electric shock?". The answer was a bit line ball, but I bought it anyway. Still works I think.

Michael

I used mineral turps in my engine cleaning spray gun on my 10EE DC drive motor...

Then a bit of metho on top of that....

I used to use petrol a lot, but as I think it is carcinogenic (or the benzene they put in it is) I have moved onto mineral turps from Bunnings... Plus water based degreaser...

Wow, a plethora of answers.
It doesn't seem too difficult a job to do even with my limited ability. I put this work in the 'black magic' box of electrical work.
Changing the bearings in electric motors is easy but I have never had to clean windings...damn black magic!!
My plan of attack is to use my degreasing gun with turps and then degreaser (water based) then seeing as how I have a hot air gun (Michael ) I will use a box of some description and funnel the air through the windings.
Any holes in that?
I have chosen this path because I have all the necessary items at hand.
I would love to borrow the megger Ray but you would have to supply a bag of ability as well.
About the only thing I know about meggers is that electricians use them to test, well, something .

Phil
ps I'm blown away by the replies guys, many thanks.

40 degrees in Ballarat tomorrow Phil. Just clean her up and leave the sun do the rest while you are at work.

Hooroo

John.