condenser fan motor - DIY Chatroom

01brothb · 07-02-2009, 08:46 PM

I recently replaced a fan motor in our air conditioning unit at work. The motor is going off on thermal overload in motor. The system has two compressors with two condenser motors for each compressor. The motor replaced runs with the compressor, the second runs once head pressure is high enough. The unit is 23 years old and this was the last of the original motors replaced. The motor is 240v single phase with a capacitor. The air is exhuasted straight up from codensing unit with air flow going across motor. Amperage is good. I thought about lowering the fan blades or slightly raising the motor. Any ideas? Thanks.

beenthere · 07-02-2009, 09:54 PM

Does the new motors amp and RPM rating match the old motor.

01brothb · 07-02-2009, 10:38 PM

It is close to the amperage and rpm. I replaced an identical motor with this same motor last year with no problems yet. The motor I used was an AOSmith purchased from United Refrigeration.

Plumber101 · 07-02-2009, 10:58 PM

Did you replace the capacitor as well?

30yrhvactech · 07-02-2009, 11:47 PM

What is the horsepower of the motor and the amp draw you are getting?

01brothb · 07-03-2009, 08:30 PM

I replaced the capacitor when I changed the motor. I think the motor is one hp. After we started the motor the amp draw was 4.3 amps. I checked again 15 minutes later and the amps had dropped to 4. The motor is listed for 4.8 amps when used with 240 volts. Would a capacitor cause the motor to overheat? Thanks for all the feedback.

01brothb · 07-06-2009, 09:47 AM

Old motor 1100 RPM 5.6 Amps

New Motor 1075 RPM 4.8 Amps

beenthere · 07-06-2009, 11:41 AM

New motor isn't really a suitable replacement for old motor.
Amp draw is low.