Has anyone experienced this? I have a fairly new Carrier unit that was working fine. Now it seems to short cycle. The compressor kicks on but only stays on for less than 5 min and shuts off. It will cycle on and off but only stays on for a very short period of time. When it is on, the air is plenty cold.
I did have an electrical problem that I believe may have caused this problem. The shore power cable was shot and had to be replaced, I know this because we were getting a hot skin on the trailer. I have replaced the cable with the correct guage wire and have had no other issues other than this current problem with the AC.
Has anyone experienced this? I have a fairly new Carrier unit that was working fine. Now it seems to short cycle. The compressor kicks on but only stays on for less than 5 min and shuts off. It will cycle on and off but only stays on for a very short period of time. When it is on, the air is plenty cold.
I did have an electrical problem that I believe may have caused this problem. The shore power cable was shot and had to be replaced, I know this because we were getting a hot skin on the trailer. I have replaced the cable with the correct guage wire and have had no other issues other than this current problem with the AC.
Anyone have any thoughts on this?
Check the position of the thermocouple probe.
If it's near the path of the cold air, it will cause the short cycle problem.
Thank you, I removed the interior cover and the probe seems to be in the correct position. This unit is just a year old and was installed by the PO. I fear that there may have been a low voltage issue due to the fact the shore power cable was bad. The fan runs perfectly. If in fact this is caused by low voltage, what component is the likely culprit? I can replace circuit boards and capacitors but would not have a clue as to the compressor or otherwise.
Your air conditioner most likely has its own circuit breaker. I would start by loosening, then tightening the screw on the breaker which holds the hotwire to the AC. In fact, check all of the circuit breakers while you're there. Your low voltage situation may have overheated the connection point, and bummed the connection. Your AC might still be suffering a low voltage situation due to resistance in a possibly bad connection.
After that, I would suspect the compressor's overtemp protection. Ask if you want details on that.
Your air conditioner most likely has its own circuit breaker. I would start by loosening, then tightening the screw on the breaker which holds the hotwire to the AC. In fact, check all of the circuit breakers while you're there. Your low voltage situation may have overheated the connection point, and bummed the connection. Your AC might still be suffering a low voltage situation due to resistance in a possibly bad connection.
After that, I would suspect the compressor's overtemp protection. Ask if you want details on that.
Tom
Tom,
Thanks for the tips. Perhaps I can give you a bit more detail, and yes I would like to know about the compressor overtemp.
For starters, I had the trailer plugged into a 20 Amp circuit at home, the unit ran fine and for about 2 hours. I unplugged the trailer and a few hours later, plugged it back in and it would run and kick the breaker on my house. I now know that I need a 30AMP circuit. (Newbie here).
I took it out on the first trip, we were in wet and rainy conditions at the campground. We noticed that we were getting a small shock from the trailer, not full voltage but a tingle. I tried the AC on the 30 AMP and it came on, compressor started and ran for about 2 min and shut down. It kept cycling on and off like that, all the while the fan is running properly. Since the temp was in the 60s I just assumed that it was not warm enough for the AC to stay on very long.
When we got back home I needed to investigate the hot skin and found that our shore power cable was completely toast. I rewired the breaker box and replaced the power cable. I removed both breakers from the box and re-installed them. Everything else seems to work just fine, and the AC has never tripped one of the breakers in the trailer.
I went out this past weekend and we were in warmer weather so I decided to try the AC again. Same thing although the compressor seemed to run longer at first power up but fell into the same 1-2 min on and then off.
I am hoping I can figure this out without resorting to a RV dealer.
Follow Inland Andy's path first - the thermostat. Does the AC still cycle even when the knob is turned to "max cold"? While your control thermocouple may be in the right position, there might be another thermostat issue.
The overtemp sensor is located on the top of the compressor, and is mounted in such a way that it can sense the compressor's temperature. Gain access to it, but don't disconnect it. Run the air conditioner until it cycles off in the way you thing is too early. Then measure the voltage from each of the sensor's pins to ground. If the sensor has kicked out, 120 vac will be measured at one pin, but not at the other.
If the compressor is too hot to touch, then your AC's problem is most likely not the sensor. If the compressor is cool enough to touch, make plans to replace the sensor.
It would be great if you had access to an inductive ammeter to get some electrical current readings on your unit.
Follow Inland Andy's path first - the thermostat. Does the AC still cycle even when the knob is turned to "max cold"? While your control thermocouple may be in the right position, there might be another thermostat issue.
The overtemp sensor is located on the top of the compressor, and is mounted in such a way that it can sense the compressor's temperature. Gain access to it, but don't disconnect it. Run the air conditioner until it cycles off in the way you thing is too early. Then measure the voltage from each of the sensor's pins to ground. If the sensor has kicked out, 120 vac will be measured at one pin, but not at the other.
If the compressor is too hot to touch, then your AC's problem is most likely not the sensor. If the compressor is cool enough to touch, make plans to replace the sensor.
It would be great if you had access to an inductive ammeter to get some electrical current readings on your unit.
Tom
Tom,
I keep my AS in a storage facility, there is not a hurry for information, I will have to bring the trailer home when I get the chance and try the things you have suggested. When you have time to list some other checks I will give them a try when I am able to bring it home and run those tests.
I really appreciate all of your help this far. I will keep you posted as I proceed.
...This unit is just a year old and was installed by the PO. ...
Louis,
If you got literature from the PO, did it include a schematic of the AC? I'm wondering if modern-day RV air conditioners have a high-pressure cutoff switch. Post a scan of the schematic if you have it.
If you got literature from the PO, did it include a schematic of the AC? I'm wondering if modern-day RV air conditioners have a high-pressure cutoff switch. Post a scan of the schematic if you have it.
Tom
I jerked this page out of the owner’s manual pdf on Carrier’s website.
If you got literature from the PO, did it include a schematic of the AC? I'm wondering if modern-day RV air conditioners have a high-pressure cutoff switch. Post a scan of the schematic if you have it.
Tom
Of course he did not include the manual, what fun would that be
I did however take a look at the manual on the Carrier Website and will download it and make a copy to keep in the trailer.
You are very welcome. You too, Tom, thanks for the Karma. I have been watching all the AC threads, especially the Carrier ones. I will be buying a High Capacity Carrier Heat Pump very soon, so I’m very interested.
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