Rooftop AC cycling

[Stopher50]

Like the title states. Compressor kicks on for about 20 seconds then kicks off for a minute then restarts over and over. Voltage is good to the trailer and replaced the capacitor. After about 5 or 6 cycles it stays on. Seems to be getting worse as time goes on. It’s a domestic unit not sure which one

 

[Texas Clodhopper]

Did you check for loose wiring?

 

[AbdRahim]

Did you reset the thermostat?

 

[Wemustrv]

It almost sounds like a weak contactor dropping out. Have you checked the roof top and cleaned the fins to ensure good airflow?

 

[TheLooks]

Thermostat or control box. Control box has a relay that powers the compressor. Thermostat tells the relay to close so it can cause this. What thermostat is in the system?

 

[jackieo]

when the last time you cleaned the evaporator?

 

[Holdmybeer]

Most common cause would be low freon and then ice on the coils ( the latter a condition caused by low freon).

 

[John&Andrea]

Just curious what the issue was with your A/C?

 

[jljones3]

Like Holdmybeer said, it's probably low on freon.

 

[TheLooks]

Low on freon will not likely cause those symptoms. It takes more then 20 seconds to freeze up and trip the freeze sensor and more time to thaw the evaporator and repeat the process. More likely a wire or relay making intermittent contact. I have seen this twice with the CT thermostat from Dometic but the OP does not state anymore info to help him out.

 

[Holdmybeer]

I'd default to Occam's Razor, in this case, the simplest and most likely culprit is low on freon.

 

[jljones3]

Low on freon will not likely cause those symptoms. It takes more then 20 seconds to freeze up and trip the freeze sensor and more time to thaw the evaporator and repeat the process. More likely a wire or relay making intermittent contact. I have seen this twice with the CT thermostat from Dometic but the OP does not state anymore info to help him out.

Low on freon is exactly what causes the compressor to repeatedly turn on and off. The system has a pressure switch which stops the compressor when it gets low enough to prevent damage to the compressor. The OP didn't say anything about it freezing up, although being low on freon will cause that also.

 

[TheLooks]

And if you went to school to fix them like I have and have worked on them all summer you would not make that arrogant statement. This is why I left this forum and others. To many experts that don't actually work on anything.

 

[Kevin D Pem]

Glad to see you got board, if only for a moment!! So! My observation started with freon. However as the poster continues, the condition changes after so many cycles. That takes freon off the table.

I think that brown out conditions are more likely the issue!

Check all connections to verify solid, clean contact surfaces. All the way back to the box⁰