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Jeff Biskup · Jul 5, 2007, 07:17 PM

I have a condenser fan on an existing Janitrol ckj36-1b condensing unit. The fan seems to have reversed direction, most likely from a power surge. There was a strong electrical storm last night and the fan is now blowing back down through the condenser, rather than drawing the air through the condenser.

The adjacent condensing unit is running fine.

Has anyone experienced this problem? Any recommendations for solution?

letmetellu · Jul 5, 2007, 07:34 PM

It is possible that you have a blown capacitor and the motor started in the wrong direction because of it. That is one thing. Does the motor seem to be running at full speed? And I will ask, knowing that you probably have tried several times to see if it starts in the same direction each time. There is a trick you can try to see if it might be the capacitor. Use a small stick and turn the fan in the right direction with the stick at the same instant start the condensing unit. Let me know what you find out.

Jeff Biskup · Jul 5, 2007, 08:43 PM

The motor runs full speed and starts consistently the wrong direction. I tried pre-spinning the blade, but it pulls back the wrong direction.

Also checked the motor rotation, and it is runner the opposite direction of what is written on the motor.

hvac1000 · Jul 5, 2007, 08:51 PM

Some motors have a plug and some you have to change the wiring but usually you can change the rotation of the motor.

One of my old tricks with motors that did not have the capability to change directions was to take the motor apart and change the shaft to the other end. This way the magnet and armature are reversed and it will spin in the opposite direction. I do not recommend doing this if you do not know what you are doing.

Jeff Biskup · Jul 5, 2007, 09:04 PM

Have you ever seen a motor change running direction like this?

I don't have the equipment to test the capacitor. But I suppose I should pull it and have it tested, and be prepared to by a replacement motor if the capacitor is good.

Jeff Biskup · Jul 5, 2007, 09:24 PM

HVAC1000,

"Some motors have a plug." What does the plug look like? Does it have a cover that pops or twists off? Do you pull it and rotate it to switch polarity.

By the way. This IS a single phase application.

Thanks to all for your help.

Jeff

hvac1000 · Jul 5, 2007, 09:24 PM

Not without some kind of a phase change. Might try a capacitor but do not old your breath.

hvac1000 · Jul 5, 2007, 09:25 PM

The plug is just a two sided piece pluged in. You unplug and rotate 180 degrees and plug back in.

letmetellu · Jul 6, 2007, 07:18 PM

Some motors have a polarity changing ability that has four short wires coming out of the motor and two each of these wires are connected to change rotation you switch the wires . This is not the right colors but I am just using this to give you and idea. You may have a purple connected to an orange and a yellow connected to a pink. To change connect the pink to the purple and the orange to the yellow. Like I said this is not the right colors for you to use just an idea of how it works. The colors you should use is or may be printed on the side of the motor.

letmetellu · Jul 6, 2007, 07:24 PM

I meant to mention that I have never seen a single phase motor change directions like you have described unless the Run, Start and Common connectors had been connected wrong, and if this did happen your motor would not run for very long without over heating and probably burning out.

acetc · Jul 6, 2007, 07:56 PM

I assume the motor was running correctly before the storm, it is probably the motor and if you replace the motor I suggest you also replace the capacitor. Try a capacitor first. Mike

Jeff Biskup · Jul 7, 2007, 07:12 AM

After doing more research, I replaced the capacitor and that corrected the problem.

According to the parts guy, capacitor failures often cause the fan to run in reverse direction. So I was even more confident that would correct the problem when I purchased the capacitor.

Thanks to all for your advice.

Jeff

hvac1000 · Jul 7, 2007, 07:58 AM

How interesting. At least you had the time to mess around fixing it which is great. Usually in the field a working contractor does not have the luxury of time so we usually just replace the motor and the capacitor. This way there will not be a call back when the motor eventually fails.