Condenser fan direction

Old 05-23-15, 01:13 PM
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Condenser fan direction

Hello everyone,

It's getting warmer in Chicago and I already fired up the A/C last week. After a little while exhaust air temperature show exactly as inlet so went up to roof to see what was going on with the unit.

Compressor was running but fan has stopped and it was very hot to touch. My first thought was capacitor. I ordered two Titan HD same rating caps, just to keep a spare, and I'm glad I did.
Caps arrived, replaced old Chinese cap, checked wiring schematic and color codes on fan motor itself so it won't run in reverse.

But, with both new caps, fan runs reverse. I'm 100% sure cabling is right, I can see the schematic printed on the fan motor from the grill and colors match, but fan runs reverse, and it sucks air from top.

However, when I pull compressor cables and run fan motor alone, it runs in normal direction, as fast as other fans on the roof, and doesn't overheat.
While it's running if I plug compressor cables, fan motor slows down and starts to turn backwards again, slower and overheats.

Like wise, compressor will run alone just fine, without the fan plugged. While compressor is running already if I plug the fan motor, it starts reverse.

I tried both capacitors, and they do exact same thing.

So, I wanted to see what happens if I separate the caps, one for fan one for compressor. Well, it worked, but why? Please explain me why do they work now? One of the motors is getting old, but which one? I hope not the compressor. I can change the fan motor myself but compressor will cost me.

Well, what I did was using 35uF side of one cap for compressor only, and 5uF side of the second cap for fan motor only, now I have two capacitor sitting next to each other. In this configuration they both started, in correct direction, spinning fast and fan motor doesn't overheat, system is cold again.

What's the deal? Why they don't work together off one cap but run fine on different caps?
Old 05-23-15, 01:41 PM
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It sounds like you may have the wrong wire on the C (common) cap terminal.

If not you'd need to post some pictures of the wiring for us.

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