Air Conditioning - AC unit turns on/off every minute
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cgsauer
08-14-08, 07:02 AM
Hi - I just purchased a 3yr old home. The AC unit cools the house just fine but literally the fan on the outside unit turns on and off every minute.
Any ideas on what this could be? Thanks
Cary
Any ideas on what this could be? Thanks
Cary
Jarredsdad
08-14-08, 03:47 PM
I'm near Zion Crossroads. Troy.
Sounds like you have a fan cycling switch on the unit that is probably not set correctly.
Outdoor fan cycling switches are used when there is a need for cooling in low ambient situations. Why one would be on a res unit beats me.
To be clear, is just the fan cycling or is the compressor also cycling?
Sounds like you have a fan cycling switch on the unit that is probably not set correctly.
Outdoor fan cycling switches are used when there is a need for cooling in low ambient situations. Why one would be on a res unit beats me.
To be clear, is just the fan cycling or is the compressor also cycling?
cgsauer
08-15-08, 12:49 PM
Hi - I actually just moved to Atlanta so I'm no longer in Virginia. Anyway, I"m not sure if the compressor is running too - the fan on the AC unit goes on and off every minute. This happens even when I turn the fan from "auto" to "on".
The unit cools the house just fine, but before I call an AC guy I just want to make sure that it isn't something that could be fixed easily. Any ideas on what could be the cause?
The unit cools the house just fine, but before I call an AC guy I just want to make sure that it isn't something that could be fixed easily. Any ideas on what could be the cause?
Jarredsdad
08-15-08, 04:02 PM
Cary are you talking about the fan on the outside unit or the indoor fan? Two very different animals.
cgsauer
08-15-08, 07:17 PM
Thanks for the reply. I"m talking about the fan outside on the outdoor unit.
Jarredsdad
08-16-08, 05:10 AM
Well, you'll need to inspect the unit and verify that only the fan is tourning on and off. And that the contactor is not cycling both fan and compressor.
If it is in fact only the fan and the compressor contactor stays pulled in look for a 3 1/2 by 3 1/3 inch box like this:
http://cgproducts.johnsoncontrols.com/CAT_PDF/1900171.pdf#xml=http://cgproducts.johnsoncontrols.com/search_lit.aspx?cmd=pdfhits&DocId=3163&Index=C%3a%5cinetpub%5cwwwroot%5c72%2e3%2e145%2e66%5cquicklit%5cexcaliburCD&HitCount=6&hits=5e+5f+13d+13e+1ad+1ae+&hc=172&req=fan+cycle wired to break the black lead to the fan. The link is to a high pressure safety, the fan control looks basically the same.
There will also be a capillary tube attached to a high pressure port on the unit. This type of control is adjustable and will have a readable scale and setting pointer.
There is also another type that looks just like a pressure safety switch (about 2 inches tall) that screws onto a high pressure port.
In either case the black (common) lead to the fan will be broken by the switch.
Turn off the power after verifying operation and check it out.
If it is in fact only the fan and the compressor contactor stays pulled in look for a 3 1/2 by 3 1/3 inch box like this:
http://cgproducts.johnsoncontrols.com/CAT_PDF/1900171.pdf#xml=http://cgproducts.johnsoncontrols.com/search_lit.aspx?cmd=pdfhits&DocId=3163&Index=C%3a%5cinetpub%5cwwwroot%5c72%2e3%2e145%2e66%5cquicklit%5cexcaliburCD&HitCount=6&hits=5e+5f+13d+13e+1ad+1ae+&hc=172&req=fan+cycle wired to break the black lead to the fan. The link is to a high pressure safety, the fan control looks basically the same.
There will also be a capillary tube attached to a high pressure port on the unit. This type of control is adjustable and will have a readable scale and setting pointer.
There is also another type that looks just like a pressure safety switch (about 2 inches tall) that screws onto a high pressure port.
In either case the black (common) lead to the fan will be broken by the switch.
Turn off the power after verifying operation and check it out.