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aoneweb
06-05-2010, 05:28 PM
I have a 10 ton heat pump unit, about 18 months old. it has two condeser motors, one is running backwards. it is an American Standard machine. any ideas as how to rectify this problem.

sedgy
06-05-2010, 06:00 PM
hi aoneweb, are the motors single ph or 3ph?

james10
06-05-2010, 06:00 PM
if it's three phase swap two of the phases over
or is it configured to do this to prevent air being dragged through the second fan opening to direct the air through the condenser coil?

Jeff Winsor
06-05-2010, 06:19 PM
Are both motors definitely running and pulling current?
If one was not running the other blade can windmill effect in the air flow

monkey spanners
06-05-2010, 06:56 PM
Duff capacitor on the one thats going backwards. When the caps go bad the motor has no starting torque so can either just sit there and hum, or start up in either direction especially if the wind gives it a little help.

If the motors and capacitors are the same you could try swapping them to see if the problem follows the capacitor, make a note of where all the wire go before you start swapping things, or take a picture.

Jon

aoneweb
06-05-2010, 07:57 PM
Thanks for all your help, I will let you guys know of my progress.

chemi-cool
06-05-2010, 08:05 PM
Many American fan motors are running on two phase with 5mf capacitor.
If you change the capacitor as Jon said, it should solve the problem.
If the motor has two phase feed, you can not change direction.

aoneweb
06-05-2010, 08:27 PM
I swapped the cables on the caps, now both motors are running in the same correct direction.
I will monitor it.
My supply temp started to drop right away, as it should.

aoneweb
06-05-2010, 08:34 PM
Thank you all.

goshen
07-05-2010, 07:46 AM
now aint that a good feeling!!

EdC
15-05-2010, 11:43 PM
Replace BOTH caps, and you will sleep better.