"Paul Drahn" wrote in message
...
On 1/15/2013 10:33 AM, Roanin wrote:
Need to replace my condenser fan motor in my heat pump. The current one
is
1100 RPM. The Tech support at Grainger's recommended one that is 1075
RPM.
Would this make a difference or harm the compressor due to the slightly
slower rotation?

R


I have to wonder why you need to replace it? Did the motor freeze up, or
is it vibrating wildly?

The reason I ask is we have owned our current place for 6 years. About 2
years after moving in, the fan on the heat pump froze up. I had noticed
the fan and motor were vibrating some since we moved in and figured it had
always done that and was really ok.

We had a local professional replace the motor. It still had the vibration,
but ran really well. Last fall, the motor began to vibrate wildly and
eventually stopped running, but was still free to turn.

We had a different company cone look at and the wires going to the motor
had burned up. The bearings in the fan were destroyed and oil had leaked
out.

The service man replaced the motor and commented on the vibration. should
be NO vibration. I had removed a length of small round wooden dowel from
the bottom of the case and showed the service man. I questioned him if
someone running that stick into the fan could cause the out of balance
vibration and he concurred and ordered up a new fan.

The old fan looked perfect, but I replaced the 4 bladed fan when the new
one came in. No vibration at all. I examined the old fan and could see a
place on the corner of one blade where the previous owner had straightened
out a bent place. So the stick had actually hit a blade.

The old fan was still statically balanced, but because the curvature of
the repaired blade was not the same as the other three blades, it was not
dynamically balanced. There was either too much pitch or not enough. I
could not tell by looking which it was.

So, in conclusion, you may need to also replace the fan as well as the
motor.

Good luck, Paul

Replacing it because it is squealing very loud after running for about 20
minutes. You bump it on the top and it quits for a second then starts again.
No vibration.

R