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Any ideas or help is appreciated

Discussion in 'Commercial' started by Rather B Riding, Jun 6, 2017.

  1. Rather B Riding

    Rather B Riding New Member

    Messages:
    186
    OK so this is the first time I've seen this type of unit and had to do troubleshooting. Its having a problem we thought another tech fixed last year. Trane voyager. All controls are inside the unit. The only thing in the space is a HW 8000 and all it does is night set back (opens a relay contact on 3&4 on the low voltage terminal block) All the VAV boxes are stand alone with fan powered heat on them and a thumb wheel for each.
    Unit lost 1 of the 2 tandem compressors last year then they found a problem that I thought was resolved. Here's what is happening. An intermittent problem but is the same as they described last year. Blower is running, first compressor came on ran for about 3 or 4 minutes then it dropped out 30-45 sec later both compressors came on at the same time. They ran for about 4 min then go back out. Unfortunately it will not always act irratic. It doesn't seem to respond properly by changing the supply air set point. I had very limited time to troubleshoot and only partial schematics. Checked most of the easy things and haven't really found much. Going back tomorrow. I'm just not familiar with this controls setup.
    They replaced the UCP board and all the pressure switches last year. Pressures are normal. I have a few things I want to check but felt like I was lost when out schematics. Anyone ever had this problem?
     
    Last edited: Jun 6, 2017
  2. Rather B Riding

    Rather B Riding New Member

    Messages:
    186
    The controls inside the unit IMG_20170606_100424552_HDR.jpg
     
  3. Jim54

    Jim54 New Member

    Messages:
    236
    Location:
    Addison, Tx.
    Sounds kinda like your controller has lost it's occupied program and the unit is running in unoccupied mode. Try this- make careful control wiring notes and disconnect the control wiring. Then jump out J6-2 to J6-4. This will put the unit in stand alone vav mode and it will operate on the setpoints on the control panel in the unit. That way you can determine if you have a unitary issue or a controller issue. Here is a link to the IOM. Page 40.

    https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.trane.com/content/dam/Trane/Commercial/lar/es/product-systems/comercial/Rooftops/VoyagerIII/iom/Voyager%2027.5%20a%2050%20TR%20IOM%20(Ingl%C3%A9s).pdf&ved=0ahUKEwiPwMiSzarUAhVI5YMKHakYAZ4QFggdMAA&usg=AFQjCNH3U4390BxCidb5q6YhCm1isQq-zw&sig2=dJshbWi9DKaPH8Kzhr_EVg
     
    Rather B Riding likes this.
  4. Rather B Riding

    Rather B Riding New Member

    Messages:
    186
    Thanks, I will. I did download the IOM. I didn't have it when I was at the unit. It doesn't have the schematics I need either. I will get them from Trane before proceeding. I did find that the economizer damper actuator has failed. The tech that was out last year is no longer with the company so I couldn't ask him any questions. Got this call late in the day and just didn't have the time. Looking for places to start tomorrow.
     
  5. Jim54

    Jim54 New Member

    Messages:
    236
    Location:
    Addison, Tx.
    Yeah it might be different for an older Voyager so getting the correct IOM is a good, good move.
     
  6. Texas-Tech

    Texas-Tech Official Geezer*

    Messages:
    16,701
    Location:
    duhh
    I hear that, they discontinued the UCP in 2003 I think
     
    Jim54 likes this.
  7. Jim54

    Jim54 New Member

    Messages:
    236
    Location:
    Addison, Tx.
    Oh hell, well I was pretty close, only missed by 14 years!:alcy:
     
  8. Rather B Riding

    Rather B Riding New Member

    Messages:
    186
    It is an 03 unit. Was like pulling teeth to get a readable schematic. All the drawings I got at the local Trane dealer were wrong. 06-09 versions. I had them email the Voyager wiring diagrams book 175 pages only need 2 schematics.