Air Conditioning - AC fan intermittent issue

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frank19991999
07-28-06, 02:02 PM
Hello,

Is the capacitor used only to start the fan motor ? My central AC unit fan motor runs intermittent. A jump start with a stick does help, however the motor stops after a some time. Today for example it stopped after a couple of minutes. I had a voltmeter contected and T1 , T2 were powered all the time.

Thanks,

Frank

Ed Imeduc
07-28-06, 02:46 PM
If it has power you need to AMP the motor to tell what it is doing. if you think its the cap get a new one dont cost that much and try it. this on and off can be in the motor and you need a new motor or it can be from the furnace board. I think more in the motor.

ED;)
frank19991999
07-28-06, 03:22 PM
If the contactor stays pressed all the time (I am pretty sure it was pressed all the time) I should be able to exclude both the furnance board, the thermostat and contactor as causing problems, right ?

Thanks

CovTiger
07-28-06, 04:50 PM
If the contactor stays pressed all the time (I am pretty sure it was pressed all the time) I should be able to exclude both the furnance board, the thermostat and contactor as causing problems, right ?

Thanks
Not necessarily but if T1 and T2 had proper voltage you are probably ok. Sounds like the capacitor from your description. The motor will run hot after you get it started by spinning and probably run much slower. You need the cap for more than just starting.
frank19991999
08-04-06, 07:50 PM
Changed the capacitor and it worked fine but the fan stopped again after 4-5 hours. In all this time the fan started OK a couple of times.
Again the same symptoms: when the fan motor doesn't start I can hear a buzzing sound from inside the unit. Pls help.

Thanks
Ed Imeduc
08-04-06, 09:23 PM
That buzz sound ????? is it the compressor It can still run with out the fan. BUT you dont want it to do that at all. If the capacitor Didnt do it next is the fan motor if you sure you have the 220V to it. Get the same HP and RPM make sure it turns the same way.

ED;)
frank19991999
08-05-06, 06:16 PM
I doubt my troubleshooting steps/skils now and I want to start from the begining.
What is the proper way to measure the voltage to the fan motor ? I have a red wire going to T1, a brown one going to one of the 3 terminals of the capacitor and a black one going to T2.

Thanks much

Frank
Ed Imeduc
08-06-06, 10:50 AM
T1 and T2 you should read 220V

ED;)