So currently I have a outside AC unit. The problem that I am having is that after 2minutes of it being on the Fan will stop running. I have replaced the motor with the equivlant part that I bought from an HVAC distributor. (I took the old motor to them) Also I replaced the capacitor that corresponds to the motor. I noticed that the copper tube that runs back to the furnace is heating up and also when you feel the center of the grill where the motor is mounted it is heating up pretty bad as well. When the fan stops you can still hear the compressor running but it sounds as if there is air escaping not sure how to describe but it sounds like a loud hissing sound. It is doing this every time. Any suggestions out there will be greatly appreciated. Thanks in advance.

Do you know if it is a heat pump or an air conditioner with gas for heating?

Also, after replacement did it do the same thing?

I should have asked as well,

Is the outdoor coil clean?

Do you have a meter and can check for over/under voltage or amerage.

Internally these motors can/will trip off in an overheat condition and can be a pain to diagnose

Quote:

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Originally Posted by thermalmedics

i should have asked as well,

is the outdoor coil clean?

do you have a meter and can check for over/under voltage or amerage.

internally these motors can/will trip off in an overheat condition and can be a pain to diagnose

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Good Morning thermalmedics, Yes this is an out door AC unit with a gas furnace inside the home. I honestly did not check to see how the old motor was acting up. I just knew it stopped spinning the fan blades. So I automatically assumed it was a bad motor. But now I know I was wrong. I would assume the old motor may have been doing the same. The outdoor coil is pretty clean. Granted it could probably use some more cleaning though but it's surrounding is pretty open for ventalation but I will try cleaning it some today. Yes I do have a meter. How exactly would I check the voltage. Do you mean the voltage going to the motor while it is running and then quits? Thanks again for your response.

Exactly check at the line side of the contactor to see if you are getting a voltage drop or rise. Then while the unit is running (even for the 2 minutes) check the load side of the contactor and see if the voltage matches or drops etc...

Check all of the wires to be sure they are secure with good connections (nothing frayed) - bad wires will heat up and draw more amps

The motor is getting hot (you probably figured this out) and shutting off on its own overload.

The heat can come from over/under voltages, amperages, dirty condenser coil, fan blade attached wrong or in wrong place, cracked blade, super high head pressures (did it cool OK before the issue with the prior motor?) mis-sized run cap. Like I said it can be a little work to find theses issues.

I had one that did the same thing and after ruling out everything we had to up the hp to 1/2 and did fine. Most common reason I find is the motor is going bad or the coil is a rug and you can rule out #1.

Keep us posted on what you find out

Ha, ha, "the coil is a rug". I like that. See it way to often, just never knew how to put it into proper terminology. I think Ill use that one.