Air conditioner woes

Spook · Jun 11, 2016

My Lennox a/c unit has started making a loud humming sound. The condenser fan starts, then quits after a couple of minutes. I replaced the capacitor, same specs, but the fan still only runs for a minute or 2? Could it be a bad fan motor, or something else. It's in the 90's here, so I think swmbo will be unhappy!

Bob · Jun 11, 2016

Typical of a shorted winding in the motor.

To verify, you need to check the motor's current draw vs. nameplate amps.

Geo-TH,In · Jun 11, 2016

Shake hands with the shaft. If there is any up and down movement, good chance your bushings are shot. Time for a new fan motor. Typically the fans may last up to ten years before they are shot. Neighbor had to replace his blower fan on furnace. It was 7 years old. But blower is used for heating and cooling, so more hours on motor. Most fan motors have no way to oil them, unless you drill a hole in the right place to add oil. Many will tell you they are sealed instead of saying they are made the old way with no way to oil them. They want a service call and repair bill. geo.

HenryO · Jun 11, 2016

you need a new fan motor. Going off on heat induced hi limit.

Southern Ray · Jun 11, 2016

Is the compressor running? Can you isolate the loud humming noise?

I just got through replacing my entire system today, new condenser and furnace unit.
Old one lasted twenty eight years.

Gary from Muleshoe · Jun 11, 2016

If your compressor is not running or getting
hot then the fan will cycle on and off.
Before you go changing the fan motor
do some more simple trouble shooting.
For one make sure your comprssor is
running.
2. If it is rinning is your insulated
line getting cold. If not compressor is
bad or low on freon.
3. Observe the contact for the fan. Is
it cycling on and off. If so fan motor
is most likely good.
I am buy no means an expert, but I do
trouble shoot them now and then.

Bob · Jun 12, 2016

"If your compressor is not running or getting hot then the fan will cycle on and off."

Hmmm, not so sure about that, but you may be correct.

On the other hand, my advice (posted quite a while ago) to check the running amperage draw of the fan motor would probably yield some useful/meaningful results.

But, GOSH, why would we do that when just posting random speculation is so much easier!

Gary from Muleshoe · Jun 12, 2016

Hummm,wouldn't that also be called trouble shooting or maybe not. I am sure you are the genius here. Thats why you are on here criticizing others.

Air conditioner woes

Spook

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Bob

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Geo-TH,In

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HenryO

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Southern Ray

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Gary from Muleshoe

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Bob

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Gary from Muleshoe

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