Compressor tripping on overload
I'm a technician who is trying to get enough posts to get professional membership on this site.
I have a R-22 Lennox HP13 series that is giving a interminent problem. The homeowner says that the unit's indoor fan runs, t-stat calling for cool , outdoor fan running but compressor not running. From the last tech that was there said compressor was out on overload and got it closed up and running again and it was a fluke thing. When I arrived this morning the unit was operating normally the pressures were good I had normal superheat the approach/subcooling was off by a little. More than likely not set right by installers. But the td was 17f at the time. I know it need to be adjusted but not the issue here. I could not get the compressor or fan to stop operating while there. I did think that since its common for lennox condenser fan motors to fail that somehow the fan wouldn't run tripping the ol on the compressor and then start running again? The seal was leaking oil for the bearings. But I couldn't prove it the head pressure was only at 240 psi if I remember its on my invoice in the van. No reason to trip out the condenser coil wasn't dirty. But the homeowner called again saying this was occuring. She was able to turn it off for a few hours and back on again but today its very hot and humid and she hasn't been able too probably way to hot needs time to cool. Any thoughts?
Originally Posted by homeless
ya keep posting a few more times and apply for pro membership!
If your condenser fan motor is leaking oil, that is not a good sign.
Did you happen to check your amp draw on the condenser fan motor and compressor?
What were they and what was the name plate rating?
If the motor did fail due to overheating it could cause the symptonms that you are describing.
The amp draws were all well in spec of the RLA's for the condenser fan motor and compressor
I had a similar problem with a 3ton carrier split system. The customer called with no cooling. I made it to the call in the late afternoon and the outside temp was finally cooling off. I found the unit with the compressor out on an overload. By the time it cooled off enough to run it would cycle with no problem. So I decided to come back the next day in the heat of the day and check the unit. I found the same symptoms. Come to find out the condenser fan motor was not turning at full speed and was letting the compressor get too hot. I wound up changing condenser fan motor and capacitor.
Maybe that helps. Good Luck.
Went back today to install condenser fan motor , blade, capacitor and customer said after I left about unit 's fan running but not cooling. I hooked up my gauges and found the txv slammed shut. Had 15 suction and 220 head. took thermal bulb off and put in hot water and it never responded. That explains why the comp was tripping on oL from the other tech and cooling interminettly will replace tommorow afternoon Yesterday worked fine had 72 suction and 188 head in the morning. Didn't see that one coming
Glad you found the problem.
I read alot of posts on this site about TXV failures.
The condenser motor still needed to be changed out due to the leaking oil.