I need some help I have trane 16xi 5 ton unit the outside unit is cycling on and off
21 min and 10 minutes off every time the t stat is set at 70
Inside temp at 75 so the outside should be running non stop
Until it reaches the set point. I have tested pressure switches
Replaced the t stat checked the float switch and it’s still doing it
Just the outside unit is cutting off and on. Any thoughts on what it maybe?

Temperature kick out on the compressor? Low refrigerant charge?

All that is good running 325 on the pressure with 91 degree temp sub cool is dead on

Looks to me like you only got 6-7 degrees. That ain’t enough

It’s 9 degrees according to the chart on the cover

Ten four buddy. Hopefully one of our real AC techs will be along to help you. Good luck!

Unless we looked at it wrong which very well could have

I had similar issue a few years ago. Ended up being low refrigerant due to leak in coil.

I was originally thinking there was to much Freon in it and
It was throwing the high pressure switch but that’s not the case
With this one according to the gauges. Thanks for the all suggestions
So far

Capacitor? There are only 2 ac guys here. Should have done spoke up

Had condensate overflow switch tripping out on mine. Unit would run a few mins like u describe and stop. Cleaned out condensate pipes good with shop vac and fixed. Switch was even still good once everything was flushed.

what you need to find out is: when it cycles off for the ten minutes, Where are you losing control power?

If its staying off for 10 minutes an AC tech should be able to check the call from the stat at the outdoor unit and then proceed from there. Is this a 4TWX6060?


On that particular unit you have a low pressure switch on the common side of the contactor and a high pressure switch on the Y side of the contactor. If it were me on this call as soon as it shut off id be checking power from the stat at the condenser and then start going on down the stream from there. Y runs from the field connection to the Y on control board , out of the YO on control board to the HPS then to the contactor.

Checking the the common side is even easier. Common(blue) runs from field connection through the LPS switch and to the contractor.

I would assume who ever is doing the diagnosing can handle and read a meter correctly, should be able to check power and then jump to each location with the other lead and find where you loose the call. I don’t know how you “tested” the switches so maybe they are ok. Could be loosing it through the K relays on the control board where it leaves as YO.

It shouldnt be that hard to find where you are loosing your call at. If you power doesnt check out at the field connections, move on back towards the air handler.

The 4twx6060 is a two stage compressor. There is a Y2 circuit but it only operated the 2nd stage solonoid.

The timing is the exact same every time?

Take this with a grain of salt, because I don’t know didly about these specific units. But, if it’s one of the variable speed compressors, I’d imagine it’s a problem with the control board. If the timing is truly the exact same run time/off time.

Have you tried turning it off and then back on?

You need someone competent with a volt meter. 10 minutes is plenty of time to track down where and why you are losing power, especially if it's over and over. There are dozens of things that could cause that, but it's near impossible to determine without knowing what your voltages are at certain points at those times.

I lose power on the r wire.

What is your system model number?

That doesn't help much, but if true- Do you think you could have a low voltage short that's not actually tripping your fuse or blowing the transformer? If it's a 2 stage compressor, it has a solenoid on the compressor for stage 2 and a rectifier and relay feeding that. I've seen many times over the past years that the solenoid for stage 2 in the compressor will short out, not blow a fuse, but still cause everything to power off long enough to reset. In your case, it may be taking the 20 minutes that you mentioned for everything to cycle up to 2nd stage, turn 2nd stage on, kick off, go through time delays and start back into the same repetitive cycle.

If it is 2 stage, with the system on and running in stage 1, jump Y2 at the condenser to Y or Red and see if it shorts out/ shuts down.