"Steve" wrote in message
...
I have a Marathon Electric 1/3 hp 1725 rpm 1 phase 115 volt electric
motor that runs the circulating air fan on my wood stove. I've had it
in operation for well over 15 years in the winter heating months and
runs quite continuously (starts and stops on stove air jacket temp)
during high heat demand - which is most of the time between November
and March in my part of the country. I am wondering if anyone might
have any suggestions on what, if anything, should be done in the way
of maintenance to insure that it doesnt crap out at a bad time being
that it has alot of miles on it?? Would it be worth taking into a
shop to be inspected / rebuilt or do I just break down and just
replace it with a new one?? I really have no idea how close to full
load amps it draws??? But it does and always has run quite hot around
the housing so that it feels quite hot to the touch. It is mounted
low and behind the air jacket of the woodstove and is pullied with a
belt to the fan. It does not get any appreciable heat build up from
the stove itself. It does have oil wells on both end bearings which I
have added to several times each winter. Any thoughts or
recommendations would be appreciated... Thanks...
Steve

Some motors blow air through the motor, some blow air around the motor.
If air is blown through the motor, check to see that blockages are not
causing the high temp.

Some motors are designed to run hot! I forgot what brand it was, but it was
a prominent mfr, and it ran so hot I called them up, and they said it was
normal for that style of motor. You could fry an egg on it!
I can't imagine that was a good design, but there it was. You could call
marathon and ask them about the temp.

Cleaning/degreasing the outside of the motor will help with heat
disappation.

Make sure that what you have for lubrication is indeed an oil well, and not
a grease port. If req'g grease, usually motors have grease fittings for a
grease gun, but not always.
Oil every month couldn't hurt, but you are already doing what 99.9999% of
the population doesn't do!!.

Getting a spare is never a bad idea:
Motors go by frame type as well, so note the frame number on the label.
Motor rewinding houses often have hundreds of motors on back shelves, and
you could get a spare for a fraction of the Grainger's price. Make sure the
shaft diameter is the same, or, if smaller, get a bushing or equivalent
pulley, and have it all pre-set up. Or makes sure the old pulley can come
off, and fit the new motor.

Have a spare belt, as well. And make sure the belt is not too tight.

Imo, the looser the belt, the better, as long as there is no slippage.
Purists will disagree, but I think the physics is on my side. Purists will
say pressing the belt in the center span should have about 1/2" play, but I
say as much play as will still prevent slippage is better:
easier on the belt, easier on the bearings, and on the pulley, and
likely results in a slightly less power consumption via less friction. A
$10 clamp-on ammeter from HF could be used to readily test this notion.
However, you don't want the belt so loose you risk it jumping off the
pulley, either.
Tight belts can wear aluminum pulleys clear away, sometimes with razor sharp
sides! And proly also too-loose belts.

I also tend to use 3L belts (thinner) in place of 4L belts, except in
automotive applications. They just seem to fit better, seem to offer less
friction. But, I'm sure this practice would make a purist's teeth hurt.

And the caution about rotation direction was good.
--
EA