Eric R Snow wrote:

Greetings Chris,
Just to give you some hope about your motor here's a little story. In
1980 I worked in a lumbermill that had lots of antique equipment in
daily use. And used hard. There were several shelves with big motors
on them that were used when another motor needed repair or
replacement. These were OLD motors. They were much larger in diameter
than long. The frames were cast iron and were cast in those nice
curves you see on old machines. Each motor had an eye on top and it
would take two guys to lift one. 2 inch diameter shafts. And these
were only 3 HP motors! Usually the reason for replacement or repair
was because the millwrights or the oilers neglected the motor because
of location. The babbit bearings would melt. And so the motor would be
switched with one that had good bearings and I would get to pour new
bearings for the bad motor and put it back on the shelf. The whole
mill was basically open to the elements. It had a tin roof and sides
but no doors, just openings. Some were pretty big. So the wind would
whip through the mill bringing rain or snow with it. But none of the
old motors failed because of insulation. Since they were open frame
motors subjected to all the wood fragments flying around the motors
would sometimes have their windings damaged from stuff jammed in them.
Some of these motors had cloth insulation. Some were equipped with
brushes. I think these were repulsion start, induction run motors. So
your motor, being protected indoors, probably has good insulation.
ERS

Thanks for the fascinating story. Whereabouts was your lumber mill? It
reminds me of some web pages about lumber mills I saw a while back. You
might find them interesting:

http://www.sentex.net/~mwandel/sawmill/asam.html
http://www.sentex.net/~mwandel/sawmill/sawmill.html

My grandfather and great uncle used to run a granary in England, but it
shut before I was born. It's a pity as it dated back over a century and
I would have loved to have seen it in operation.

I think there's a good chance my motor's insulation is okay, but if not
I'll probably get it fixed sometime anyway.

Best wishes,

Chris