Kemarus King–How a Condenser Fan Motor Works

HVAC Technical Academy
Sanford, Florida
May–June Session

Hey, how you doing? I’m Kemarus King. I’m here at HVAC Techncial Academy and today I’m going to talk to you about condenser fan motor.

I already took the screws out here, but the condenser fan motor is right here. It sits at the top of the condenser unit, right above the compressor.

Going to take this off for you right quick. I already disconnected the wires as well.

And it’s not this actual blade right here. You have to take apart the set screw. I have one right here that I took out on my other unit.

Usually, you take apart the set screw with the wrench right here. It might be loose already, but keep it going.

And it’s a little rusted, but usually when you take this off, you can use a pulley or anything. You take the blades off and this is the condenser fan motor right here.

Now, the purpose of the condenser fan motor is to draw outside air across the condenser coils, helping the condenser coils turn that superheated high-pressure, high-temperature vapor into a high-temperature, high-pressure liquid.

Now, when it does so, it also releases that heat upwards. That’s why whenever Mrs. Smith goes over to her unit, she goes, “It’s hot up here.”

Typically, when the condenser fan motor goes bad, you’ll see the condenser blades or the fan blades, they won’t move or it might be hard for it to move.

Maybe it’s not the blades. Maybe it’s not the condenser fan motor. Maybe it’s actually just a bad capacitor.

And today I’ll show you how to test that as well.

I’ll show you how to test the integrity of your wires. I have it set here already to resistance.

And the best way to check it while it’s off right now, you get these wires right here, is to check and go through all three wires.

And you can see it’s 130 right there. This says 50. Can’t see it because it’s not transparent right here. And it says 80.

Usually these numbers will add up to the bigger number.

And these three wires right here, I didn’t tell you earlier, but they’re your common, your start, and your run.

One goes to your capacitor, one goes to your contactor, and your common. It goes all the way. This common came from the defrost board right here.

Now, to save Mr. Smith a lot of money, you don’t ever really want to diagnose a bad fan motor.

Typically, you want to start at checking your voltage at your capacitor.

This has been very fun, guys, but get out of here. I got some work to do.