Electrician Talk banner
41 - 43 of 43 Posts
We were starting a 4160 motor that wouldn't meg clear. The motor shop had us dry out the windings by shorting a welder through the windings for about three days.
That's a new one for me; I have not heard of the technique. Most MV motors I have dealt with have on-board built in heaters.

I'll stuff this in the memory banks under "last resorts to dry out a motor". You just never know...

Mark
 
That's a new one for me; I have not heard of the technique. Most MV motors I have dealt with have on-board built in heaters.

I'll stuff this in the memory banks under "last resorts to dry out a motor". You just never know...
With a high air-flow it works great on wound equipment. Transformers, too. Separate the windings and hook a welder to each one.

For really large rotating equipment where a welder can't produce enough heat, like a big synchronous generator, the MO is to short circuit all three phases put in over-temp and overcurrent protection, and actually use a big welder to provide low-voltage excitation while the unit is rolled.

You create short-circuit current in your stator at basically no voltage and it will dry itself.

The danger being obviously if you over-excite or over-speed your protection had darn well better work or you can burn the unit up. But sometimes it's the only way.
 
41 - 43 of 43 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top