air con won't blow
I'm working on a roof unit in which the squirrel cage blower motor won't run. With power off, it spins freely by hand. With power on, the motor hums but does not run, and if I try spinning by hand the...
Forum Discussion
wa8yxm wrote:I am Yu wrote:
OK, it has a fan capacitor, a run cap, and a start cap. I only need to worry about the fan cap, right? (I can hear the compressor coming on.)
Fan cap is marked 7.5 microfarads +/- 10%. Measuring with a Fluke meter gives 6.51 microfarads. Does this mean it's bad... bad enough to cause the motor to lock up?
The fluke meter reading means nothing.. A capacitor can test out good on the fluke at say 9 volts peak (or less) and still be toast at 120 volts.
Maybe it's possible, but every one that my meter said was bad was bad and replacing it fixed the problem. I have never had a false reading on a cap check. I've checked many of them and have never had a bad one read good.
