Trane RTAC 155 comm issues

[Jimb416]

I have 12 sensors/transducers which will not communicate causing the chiller to remain in a lockout condition because this is affecting both circuits. I eventually narrowed it down the compressor 1 intermediate oil pressure sensor plug where a critter chewed through the 4 wire communication wire. I was able to repair and once completed I tried ‘binding’ the sensors and transducers via Trane’s laptop software. I had the same result with the same 12 not communicating? Has anyone experienced anything like this? This is the first time I’m getting into the binding and use of the software to this extent so I could also be missing something or skipping a step.


Thanks,
Jim

[chillrdude]

Check your sensor power supply, start unhooking sensors until you find the one bringing down your comm loop, you really been a member since July of 2013 and this is your first post?

[Buka]

You take an oscilloscope, and check the communication line of sensors and transducers. 485 protocol will give you excellent rectangles without interference. Where mountains appear something is wrong.

[Sserrviceman]

RLC-SVD05A-EN Trane manual also may help in troubleshooting problems with multiple LLIDS.

[Nicolitz]

If it affecting both circuits it might be the communication line the old ribbon type tend to break when handled.