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  1. #1
    Join Date
    Jul 2005

    Trane zn520 issues...


    A couple questions re: this board.

    In Rover I can communicate with the bus fine but one particular zn520 does not show up even connected to it's zone sensor. No heartbeat on board disconnected from bus and no flashing led when on bus... Have not tried direct connect to board but I know comm from zone sensor to zn520 is OK, board belly up?

    When I replace this board I planned on copying config from a good board and downloading onto the new one... I have 10 classrooms with same config, ok to do it this way or do I have to do all settings on new board from scratch?

    One classroom has 2 CUV's with one zone sensor, one shows no comm. Anything special needed to twin 2 CUV's to one zone sensor?


  2. #2
    Join Date
    Jul 2001
    I would grab a new board b4 going back out to the job, but I would connect my alligator clips directly to the original board and scan for it before I replaced it. Disconnect the comm link and scan for the board. If nothing shows up the push the service pin. You should see a message that says "servin pin press received" and the board should show up. If still nothing you can cycle power to the unit and try again but it's probably a bad board. If all the configs are the same then it's a smart idea to save the config from a known good card and download into the new card. Also to master/slave the fancoils you must create bindings in active mode assuming their is no supervisory controller on the link.


  3. #3
    Join Date
    Feb 2006
    what happens if you hit the service pin? (you can also initiate a service pin by holding the "on" button on the zone sensor for 5-10 seconds)

    Does the comm from the sensor to the board terminate to a terminal board or directly to the ZN520? The reason I ask, is that I have seen in the past where the wiring diagram shows you landing wires on say LTB1-1 and LTB1-2, but there is nothing going from those terminals to the board.

    If you are sure that you are connected to the board, and it still won't communicate, then it could be bad.

    And yes, if it is the same as the other units, you can just copy the config from one of the other ones.

  4. #4
    Join Date
    Jul 2005
    Thanks for the assists fellas... I had tried wink and the service pin with no luck, picked up new board this AM and installed it just now... working great. I also talked the Trane local office into giving me the book for these boards... I like to have as much backup as I can get especially with the Trane stuff.

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