Pump Runs, Fan Doesn't, Fan Can Be Hand Started - But Runs Slow

Old 06-23-11, 11:46 PM
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Pump Runs, Fan Doesn't, Fan Can Be Hand Started - But Runs Slow

Hi Folks. Thanks in advance for your help with this.

I have a Rheem condensing unit on the roof. When I turn on the AC the pump turns on, but then the system turns itself off and I have to push the overpressure reset button. But then I noticed the fan was not running (which mostly likely causes the overpressure). But I can get the fan started by hand (or by stick), but it appears to run very slowly, and the unit still turns itself off in overpressure.

This unit has two capacitors. A smaller start capacitor for the motor. And a dual run capacitor. I had assumed the problem was the start capacitor, but then after hand starting the motor and it does not run fast I am not sure.

The dual run capacitor may possibly be showing sings of being bad. A little fluid marks on the top and maybe signs of bulging. But nothing really obvious.

My questions:
Could the start capacitor still be good, and the dual run capacitor be causing all the problems?

What would be causing the motor to run slowly once it is hand started? I had assumed that if the start capacitor was bad, then if I got the motor going by hand, everything would work fine (until it turned off).

I should note that the fan moves very freely and does not appear to have any bearing play.

Thanks again for your insights. We are roasting with our AC tonight and I need to get it fixed tomorrow.
Old 06-24-11, 04:17 PM
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There is no start capacitor for the fan....... replace the dual run capacitor first or take it to a motor shop and have them test it for you. if it tests good then you need a new fan motor but I would replace the run cap with a new motor no matter if it is still good or not.

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