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  1. #1

    Trane units with Lon interface not heating

    Good afternoon. Bringing some Trane units with Lon boards in them into Niagara AX. Trying to make sure that everything works, and have figured out everything but the heat. There are two different style units:

    Type A: The points that I see that I would think might have something to do with heat are: setpoints (unoccupiedHeat, occupiedHeat, occupiedCool, and unoccupiedCool), nviApplicMode, nviAuxHeatEnable, and nviOutdoorTemp

    Type B: Possibly related to heating are: DAClSp/DAHtSp (discharge air cooling and heating setpoints), setpoints (unoccupiedHeat, occupiedHeat, occupiedCool, and unoccupiedCool), nviApplicMode, nviPriHeatEnable, and nviOutdoorTemp

    I have tried lowering the outdoor temp to a range that would typically allow heating, raised the cooling and heating setpoints above the nvoSpaceTemp, changed the DA setpoints, put the units into unoccupied and adjusted those setpoints...nothing seems to get the units to heat. There are no morning warmup points, the units do have heating sections and are connected to gas. Is there anything else that might lock the heat out?

    Thanks!

  2. #2
    Join Date
    May 2011
    Location
    North Carolina
    Posts
    314
    Depends on the type of unit and how Trane has it setup. Looks as though Type A is space temp control. Make sure your occ and unocc setpoints are in the correct order. Looks like Type B is doing discharge air control. Are there VAV boxes on this unit? If so the heat will only come on for morning warmup or daytime warmup. You can't command it on at any other time.

  3. #3
    The setpoints are in the correct order, highest is unocc cool, lowest is unocc heat. We made sure to bring the standby setpoints in too. There are no VAV boxes on the units. Are there any jumpers/switches/settings on the unit that we can look at to see if it is setup to have heat? Thanks

  4. #4
    Join Date
    Oct 2003
    Location
    Michigan
    Posts
    733
    SCC or DAC?
    Beware of the prophet trying to make a profit.

    There is less oxygen from knee level to the floor! Check it out next time you tie your boots.

  5. #5
    I know one is SCC (first type), second has points for DA and regular setpoints.

  6. #6
    Join Date
    May 2011
    Location
    North Carolina
    Posts
    314
    Quote Originally Posted by theintegrator View Post
    The setpoints are in the correct order, highest is unocc cool, lowest is unocc heat. We made sure to bring the standby setpoints in too. There are no VAV boxes on the units. Are there any jumpers/switches/settings on the unit that we can look at to see if it is setup to have heat? Thanks
    I'm not much on the mechanical side but most Trane units have a set of contacts where you can cycle it thru test mode. All the compressors will fire, fans on and heat if it's set up. You have to power cycle it to get it out of that mode.

  7. #7
    Join Date
    Jun 2006
    Location
    New Jersey
    Posts
    4,340
    Quote Originally Posted by theintegrator View Post
    Good afternoon. Bringing some Trane units with Lon boards in them into Niagara AX. Trying to make sure that everything works, and have figured out everything but the heat. There are two different style units:

    Type A: The points that I see that I would think might have something to do with heat are: setpoints (unoccupiedHeat, occupiedHeat, occupiedCool, and unoccupiedCool), nviApplicMode, nviAuxHeatEnable, and nviOutdoorTemp

    Type B: Possibly related to heating are: DAClSp/DAHtSp (discharge air cooling and heating setpoints), setpoints (unoccupiedHeat, occupiedHeat, occupiedCool, and unoccupiedCool), nviApplicMode, nviPriHeatEnable, and nviOutdoorTemp

    I have tried lowering the outdoor temp to a range that would typically allow heating, raised the cooling and heating setpoints above the nvoSpaceTemp, changed the DA setpoints, put the units into unoccupied and adjusted those setpoints...nothing seems to get the units to heat. There are no morning warmup points, the units do have heating sections and are connected to gas. Is there anything else that might lock the heat out?

    Thanks!
    Is nvoHeatCool ever going to HVAC_HEAT...with nviApplicMode set to HVAC_HEAT? If it isn't, then I would be double checking nviPriHeatEnable(for the DAC) and nviAuxHeatEnable(for the SCC). Remember these points use both state and value. If it is, then I would be checking the units mechanically.

    Here are the manuals for the cards........I'm assuming LCI-R.

    DAC- https://dl.dropboxusercontent.com/u/...ll%20Guide.pdf

    SCC- https://dl.dropboxusercontent.com/u/...ll%20Guide.pdf

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