Cool 1 is NOT the same as compressor 1. Compressor 2 is the smaller of the two compressors. That will always be the first on last off. This is stated in the manual a couple times. The contactor failure faults you are having is because you have Y1 and Y2 jumped out. If the aux switch makes without a call it thinks the contactor is welded.
I have the same issue on a 7.5ton proving switch 1st stage issue, and tech supports no help. I replaced the contactor and aux without resolution. Did you find a solution?
We replaced contactor and micro switch and 2 days later ordered a Dainkin unit. We are experimenting with gutting controller on a few units but have not made a final decision to what methods we will use in the future....
Bottom contractor is actually circuit #1. Schematic is labeled wrong. Small compressor is 1st stage. Don’t ask me how I know. Had this exact issue and scratched my head for awhile. Check incoming voltage. Trane taps all their transformers for 240v. Had to tap the transformers for 208v. Haven’t had a single trip since. My control voltage went from 23.2v to 27v. Tranes are super sensitive to anything below 24v
Anybody having issues with these units not dehumidifying in 1st stage cooling? 33% cooling capacity and 66% fan speed. 50+ degree saturated suction temperature not below RAT dew point. I’ve lowered the “max fan speed” as a temporary fix but then when unit runs 100% cooling capacity it like 230cfm/ton.
Cool 1 is NOT the same as compressor 1. Compressor 2 is the smaller of the two compressors. That will always be the first on last off. This is stated in the manual a couple times. The contactor failure faults you are having is because you have Y1 and Y2 jumped out. If the aux switch makes without a call it thinks the contactor is welded.