Fan on Outside Unit reverses direction when compressor kicks on
I have a Lennox 12ACB30-4P Value Series manufactured in 1996. It came with the house I bought 3 years ago. The unit never gave me any problem until 1 week ago when it would not cool. The fan would run, but the compressor would not kick in. There was a buzz every 20 seconds or so.
A tech was called based on the sticker on the unit (original installing company, but the residential service was sold, the new company still have service records.)
First tech looked and the wire was disconnected from the capacitor. He replaced it and cleaned it. All was well for 3 days, and there was no cool air again. The buzz returned in an interval of about 1 minute.
Called the company back and argued about cost of having to fix the same problem twice. Second tech came out the same day. The wire was disconnected again. This time, he replaced the capacitor and said the fan is running is reverse.
I thought I was crazy as I remembered the fan running in the correct direction (counter clockwise with air blowing out the top) before the capacitor was replaced. He left when the air is cool again (60F at the vent). I then turned off the unit by kicking the thermostat high. then waited several minutes.
When I started it again with the thermostat, the fan was running counter-clockwise with air blowing out the top. As soon as I heard the buzz and the compressor properly kicked in, the fan REVERSED itself to run in clockwise direction, with air blowing out the sides. I called the tech back, he said he has no clue and has to research. AFAIK, I do not think either tech has touched the fan itself.
Here are a couple questions:
1) Is it safe to run the AC in this condition? Would the fan motor and/or the compressor be damaged? I do not know if it was always running like this before the capacitor change.
2) Could the wiring on the capacitor be causing this? That is, could the second tech have wired the capacitor wrong?
Thank you. I appreciate any input.
Last edited by Mounty; 05-23-2009 at 06:28 PM.
First off, there is no pricing in open forums. I'm sure it will be edited soon if you don't.
I won't get into the technical stuff and won't get into trying to lay blame on a tech.
A bad capacitor CAN cause certain motors to run in either direction.
Is that your problem? Impossible to tell from here.
I would not allow the unit to continue to run this way. It is designed to function with a certain amount of airflow. You aren't getting that.
Oops, I did edit the price out, sorry about that. I am not looking for blame, but rather solution. The first few paragraphs are just background info.
The fan is not running in random direction. It runs counter-clockwise with the compressor off, like for the first 2 minutes when the thermostat turns the system on. As soon as the compressor kicks on, the fan reverses itself.
He left the box which the capacitor came in, and I am just going to assume the new capacitor is good. Would his wiring make any difference such that the fan would reverse itself when the compressor kicks in? Thank you.
Edit: Here is what's on the box:
Dual Run Capacitor 45-5 MFD - 440VAC
What part of the country are you in Mounty???
Quite honestly it sounds like (and this is not pulling punches)......
......You had 2 crappy techs come to your home and neither one of them solved any bit of your problem.....
This is an electrical issue that any good tech who knows how to read a schematic can fix....
I'm sorry you have wasted money on crappy techs.....my advise would be to research the companies in your area....find a good company that guarantees their repairs....
I need a new signature.....
Hi I_bend_metal, thank you for replying. I am in Cincy. One thing I did do was to remove the panel and check the wiring. It looks like he wired it correctly according to the schematics.
It's a long weekend, so he is not likely to come back till Tuesday, but since he said he would research the issue, I will see what he has to say on Tuesday. You are right though, I should have known to ask if they guarantee their works, live and learn I suppose.
So far I have had one response that might be plausible, a low resistant short to ground on the fan. Any idea? Thanks.
I agree with what you've been told. I would like to ad. Do not attempt a fix by yourself. You may not only get hurt and damage your unit, but you will let them off the hook. I have seen a cap wired backwards but the fan never ran in right direction at all. So it must be something else.
not getting to technical here, but;
does anyone find this statement odd,"...It runs counter-clockwise with the compressor off, like for the first 2 minutes when the thermostat turns the system on. As soon as the compressor kicks on, the fan reverses itself."
Yes, this is strange, sounds like you got 2 unqualified techs. Sounds like something is wired wrong.
Well, that's based on my observation. I can only guess that there is some sort of delay. I will try to explain more.
If the AC is off for a while, the fan comes on in reverse and the compressor also kicks immediately as it gets a signal from the thermostat.
If I turn up the thermostat so the compressor stops, wait 30 seconds or so, then turn down the thermostat, the fan will come on first in the correct direction. When the compressor kicks in after a delay, the fan reverses and stays that way until it is cool enough.
Edit: When the compressor turns off, the outside fan stops as well. I am strictly talking about the outdoor unit.
Hope I didn't complicate things more.
LOL, just my luck, eh?
Originally Posted by andserco
Why is the compressor kicking on after the fan? Does the compressor try to kick on with the fan initially? Sounds like a wiring, voltage or capacitor problem to me. We've had a few lennox cond motors crap out and run backwards over the years.
When you turn the stat up to turn the unit off both fan and compressor should not run. Then if you turn the stat back down right away it will lock both the compressor and the fan out for 5 minutes. This is a safety feature. After the 5 minute lock out both the compressor and fan should start at the same time. The fan should not start and then a couple minutes later the compressor start. It should be a simatanious <sp> start up. Your unit is a simple 12 seer single stage R-22 unit. We could guess and speculate but without being there with a meter, thats just what it is. The fan running backwards is not a hard fix until you added running before the compressor start and changing directions. Thats a new one in my book also. Can you post what happened and how they fixed it please. In case I ever run into this as a Lennox dealer.