Help with a Trane R.T.U

[jdlowe]

Model # TCD240BW00EA
Serial # M21105124D

I am new to R.E and I am currently working on the unit mentioned above. The unit is shutting off with no explanation (no fault code on the red light on board). I used a tattle-tale on the power supply and when the unit shut-off there was no difference in voltage or amperage readings. The unit shuts off at completely random times. To get the unit to restart, the power supply must be disconnected and reconnected(ie; fuses removed&replaced, breaker reset, disconnect off then on, etc. I am stuck. I am starting to think it could be the main board, but am still unsure. Please help me!

[stinger440]

Not sure exactly what type of zone controls you have so I am making a guess. Check the J6-1 and J6-2 terminals on the RTRM board. If you are using a Zone Sensor for this unit and it does not get a signal there the unit will shut down. Is the green LED on the board flashing after it shuts down?

[tonyhavcr]

When the unit is off when you know it calling jump the test terminals if the unit works its the controller or wires.
If not dose it have a economizer and was the damper open is so then let me know

[Djorn]

I worked on one Trane unit that had similar problems, and ended up changing the economizer controller on the Honeywell economizer motor. The intermittent problem seemed to go away after that. The problem was not repeatable at the time of service, and there was no pattern to the lockouts, but the unit was in total lockdown with no fault indicated on arrival.

[jdlowe]

Yeah, i disconnected the economizer, problem still occurs, LED light stays solid red, no matter what. I am going to do the test terminals tomorrow. Thanks guys

[tonyhavcr]

Hi when you disconnected the economizer did you cycle the unit off and on to clear the brain and did you remove the dat plug it the only one that needs to be removed.

If you do the test or jump it and the unit dose not work then its the board.

Most of the problems with the economizer are not set right and a single stage stat installed when you need a two stag or 2nd stag of a two stag not hook up to y2

[serviceman]

If the drive is for in 15 minutes after starting its work verifies that open air flow switch contact