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Old DC Motors not used

Old DC Motors not used

(OP)
Dear Experts

We have a few old DC motors (see pictures) that have not been used for many years.
Can anyone tell me how to proceed to put them back in working conditions?
As you can see the windings are in very bad shape (dirt, rust and moisture acummulation)

Thanks in advance!















RE: Old DC Motors not used

If the insulation is flaking off, time to rewind. If not, clean, dry out and test.

Muthu
www.edison.co.in

RE: Old DC Motors not used

And look at the bearings. It looks as if a bearing was failing.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Old DC Motors not used

That's the commutator Bill. tongue

RE: Old DC Motors not used

Bill's commutator phobia is a well-kept secret. Now you have spilled it, Scotty.

Muthu
www.edison.co.in

RE: Old DC Motors not used

(OP)
My plan is to:

1st clean as good as possible using vacuum machine, light brush and air gun
2nd Dry for 3 hours at oven at 105 ºC
3rd Varnish the whole windings
4th Dry at oven for 2 hr at 80 ºC

RE: Old DC Motors not used

I am a little concerned with the scuff marks and missing paint inside the stator and on the surface of the rotor, not the verdigris on the commutator.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Old DC Motors not used

Amusing off topic side story triggered by Bill's comment; a friend had copper gutters installed on their house this past summer, I just saw them and they were already green. Turned out they PAID EXTRA to have the verdigris "added"!


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

RE: Old DC Motors not used

5th - Test all windings and brush holders before assembly.

Muthu
www.edison.co.in

RE: Old DC Motors not used

(OP)
edison123: Please explain how do you recommend to test the windings?

RE: Old DC Motors not used

Armature
IR value. Bar to bar DC resistance. Surge comparison test. Commutator roundness.

Both Field windings
IR value. DC resistance. AC pole drop test and/or Surge comparison test.

Brush holders
IR value.

Muthu
www.edison.co.in

RE: Old DC Motors not used

At disassembled DC motor is good to check the polarity of the main and auxiliary poles .At rotor you should check possible inter-turn shorts .
Good luck !

RE: Old DC Motors not used

(OP)
Update: The motor could not been restored.

So it has been fully rewinded and it is working OK

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