Cold stripping of stator coils

A solvent is available in the Indian market which can be used for removing the stripping (Removing) the varnish and the hard coatings available in the market.

One of the manufacturer in ELITE Industries (Mumbai, INDIA) (Tel:- +91 022 55795789, Cell:- 09323803588)

It is the best ever solution used for stripping the coatings on high voltage transformers also.

Regards,

Vinayak.

Hi koshy

You do not indicate where you are...it would help in the replies..different rules apply in different countries as to the product you are able to use..

Wearing proper protective gear, use a thin cut-off wheel mounted at the bottom of a vertical spindle, with the stator (minus end bells) standing on a "turntable".

Cut-off one end of the coils, just above the iron ... then, flip the stator over, and use a chain-fall or other pull-tool to drag the remainder of the coils from the slots. This will most probably require some "extra" tool work ... e.g., running a cut-off wheel along the tops (lengths) of the slots themselves, and perhaps even "starting" the movement of the remaining coils using a maul and appropriately-sized drift-punch tool.

Of course, if the windings are really epoxied-or-varnished in there super-well, you might HAVE to resort to a solvent-stripper or burn-out.

Hoping the best-of-luck to you ~

I think you are confusing "stator' with rotor.

Stators do not have endbells.

Well ~ ONE of us is thinking erroneously...

[You do know what an 'end bell' is, do you not?]

"Granted" ... Koshy didn't state whether he might be dealing with an 1800hp synchronous motor, or other beast having babbitt bearings on pedestals (thus, no end bells) ... but by the nature of his post in general, I'm assuming typical 50 to 250hp 3Ø units.

Visit the "favorite-of-dummies" page, here and read 2 lines ("Components").

Take a peek at this snippet from a quality source [Electrical Machines and their Applications; John Hindmarsh] ...

and , until Koshy defines the "large motor" to which he is making reference a little better, please explain to us all where YOU believe that "end bells" are configured on a "large motor".

As Travolta's character in "Phenomenon" asks: "Let's be specific, Bob!"

Best to all ~

It has been years since I have done this kind of work. What we did was 24 hours in a burn out oven, then chop of one end of the windings and hook on to the loop at the other end and apply brute force. This was usually in the form of an hydraulic ram with a hook. On larger motors/generators the overhead crane could be used with gravity holding the other end.

If you are tempted to use solvents to remove the varnish/insulation make sure that you have lots of ventilation or someone else doing the job.

BAB