On 1/19/2013 7:06 PM, Unquestionably Confused wrote:
On 1/19/2013 5:21 PM, Artemus wrote:
"Keith Nuttle" wrote in message
...
I realize this is not probably the best place to ask this question,
but collectively
the people on this form have experience with every thing.
[snip]
Is it normal for a small motor like is on the fan to run hot? This
one is running
about 200F. (taken with thermoprobe on a volt/ohm meeter with the
probe on the out
side of bearing housing over the bearing.)


Measure the temps at other places in the motor. If the field windings
or iron are excessivly hot you may have a shorted winding.

Several have mentioned the possibility of shorted windings.. Depending
upon how long that motor was "stalled out" when Keith noticed the
problem, might that not be the problem now? If the bearing/bushing
seized up and let the motor cook long enough, simply freeing up the
bearing isn't going to do much if the windings have now become a "hot
plate"

Any idea how long that puppy was powered up and just sitting there
groaning, Keith?


OP: The first time it stopped; no. It was the first cool evening of
the fall. I turned it on and went about watching TV, and checking the
newsgroups on the computer etc. Some time later I noticed the fan was
not running. Other times I was monitoring it so it was stopped for a
minute or to until it was turned off.

The comments about the windings shorting could be true as the wrapper
around the coil has darkened, but on the bench they did not seem
excessively hot. The coil resistance is about 9.5 ohms with my cheap ohm
meter. There is no continuity to the ground on either tab.

From the first my working theory was the a piece of lava stone got
sucked into the fan, and blocked it from turning. The lava stones have
been removed. Now I am wondering if that is what happened and the
symptoms I am now experiencing are related to the initial stoppage.

This after noon the fan ran at about 200 for about 7 hours and was
running well when I turned it off.

With your comments I believe I will do further testing with it in the
fireplace. A new one will cost about a hundred dollars, and a service
call would be more than that.

It is a cheap motor not worth spending any money to rebuild it,though I
may check with the local fire place shop an see if I can get the motor only.

Thanks for all of your help.