Varnish Electric Motor Windings

Works just fine with a high current DC source too! (Welder) Just make sure you have some way of monitoring the temperature.

Thanks tcmtech.

yes, you can do this. i did dry a 1000kVA Alternator using a Welding Xformer once. But, do monitor the heating device as it may get heated-up & fail during the process.

Thanks, so i have to keep an eye on the windings so that they do not overheat. I think if we have an amp meter we can monitor the amps for that perticular windings. Say if the name plate reads that full load amps is 10amps then we can keep it some where at 8amps to avoid burn out.

I would STRONGLY recommend monitoring the temperature as well as the current. Connecting the windings together and operating the motor on either DC or single phase AC with the motor stationary (ie no cooling) is well outside the normal operating parameters of the motor and it likely only be able to handle a small amount of its full current rating.

If in doubt start off with a low current (say 1 or 2A) and carefully monitor the temperature of the windings using thermocouples (or similar). Increase the current if necessary.

Thanks for the best advice. Thanks everyone.

definitely monitor the winding temps closely. The areas buried in the core slots will heat up a lot faster than the ends will.

I have used the DC welder method to process old motors and transformers for scrap many times. And a few times just to get the enamel burned out of the windings so I could disassemble a motor for rewinding. If done properly the old windings can be pulled right out of the slots with very little effort. All the enamel and paper turns to ash and no longer holds anything together but the iron core is completely unaffected other than needing to be cleaned off and repainted.

And you do need a rather good size and quality DC welder to do this. I have a Miller Shop Master 300 that has no problem with holding a 200 amp load for up to 10 minutes while burning out a bigger motor or transformer.

Thanks Tcmtec