FX40 schedule for a AHU102 controler
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  1. #1
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    FX40 schedule for a AHU102 controler

    I have an FX40 connected (N2 bus) to a few JCI AHU102 controllers. I have a problem with one schedule not turning off a return fan for one unit. When looking at the schedule I see both the supply and return fans there, The supply fan turns off but not the return fan. The only difference I see when looking at the schedule is the "value" field,
    supply fan------ off {overridden @ 16}
    return fan------ on {OK @ 16}
    The other three AHU's all show "overridden @ 16" for the value on the schedule page except the one fan that will not turn off.
    Screen shot below.
    http://slipkid.smugmug.com/Others/Mi...5_23drX-XL.jpg

  2. #2
    Join Date
    Jul 2007
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    65

    RE:Schedule

    What point are you scheduling?

  3. #3
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    Louisville, KY
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    7

    Those AHU's...

    Deleted original post.
    Last edited by bbaispecialist; 04-28-2010 at 01:22 PM. Reason: Apology: Did not want to be seen as advertising a service.

  4. #4
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    New England
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    Quote Originally Posted by Cal1 View Post
    What point are you scheduling?
    I am scheduling a supply fan and a return fan:
    SF-C....................supply fan
    RF-C....................return fan
    The problem is with the return fan.

  5. #5
    Join Date
    Jul 2007
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    65

    RE:Return Fan

    Do you have a occupied BD point? Just curious why you are scheduling the fan command itself and not the occupied command.You could also schedule the shutdown command BD 197 if need be. Any chance that the point is in override in the controller just a thought. Is the BO on the correct terminal on the AHU controller maybe someone moved the point.

  6. #6
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    Quote Originally Posted by Cal1 View Post
    Do you have a occupied BD point? Just curious why you are scheduling the fan command itself and not the occupied command.You could also schedule the shutdown command BD 197 if need be. Any chance that the point is in override in the controller just a thought. Is the BO on the correct terminal on the AHU controller maybe someone moved the point.
    I took over this building after the fact, with lots of programing problems. There is no occupied BD point. All the AHU's in this building have the scheduling commanding the BO directly. The units work correctly except for the return fan on this unit. I checked the point for any overrides, there are none. The only difference I see on the return fan is in the "point details manager" tab. The return fan RF-C "OUT" section says "on {OK} @ 16". The supply fan says SF-C "on {overridden} @ 16".

    http://slipkid.smugmug.com/Others/Mi...43_fh99L-L.jpg

  7. #7
    Join Date
    Oct 2009
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    "OCC-C" is the point that you want to add to the schedule. Its the third point up from the bottom in that picture.

  8. #8
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    Quote Originally Posted by Igotworms View Post
    "OCC-C" is the point that you want to add to the schedule. Its the third point up from the bottom in that picture.
    I will try that this Friday.

  9. #9
    Does not sound like it is working right. I would not think you would desire to schedule the fans. You will probably need to make changes once the problem is found in FX programing.

  10. #10
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    Quote Originally Posted by SuperDuperTech View Post
    Does not sound like it is working right. I would not think you would desire to schedule the fans. You will probably need to make changes once the problem is found in FX programing.
    The problem I face is I don't have the workbench software. I only have access to the FX40 via Internet Explorer and the JCI HVAC Pro software.

  11. #11
    Join Date
    Feb 2009
    Location
    Northeast
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    You should have everything you need with the browser interface. Really depends on user permissions and the NAV file. At this point I would delete the link from the link sheet and recreate it on the RF. Then comes the question if the program is what they want. Normally the AHU controller would be scheduled with the OCC-C point. This allows the ZN-T to cycle the fan at night plus some other stuff. If all they want is the fan s off, then what they have will do that. The real problem may come if the controller were to go into shutdown or unoccupied mode with the fan scheduled On. As they say "unexpected results may occur".

  12. #12
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    Quote Originally Posted by billcontrols View Post
    You should have everything you need with the browser interface. Really depends on user permissions and the NAV file. At this point I would delete the link from the link sheet and recreate it on the RF. Then comes the question if the program is what they want. Normally the AHU controller would be scheduled with the OCC-C point. This allows the ZN-T to cycle the fan at night plus some other stuff. If all they want is the fan s off, then what they have will do that. The real problem may come if the controller were to go into shutdown or unoccupied mode with the fan scheduled On. As they say "unexpected results may occur".
    I will be at the job site on Friday and try a few things out.
    Thanks

  13. #13
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    New England
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    Quote Originally Posted by billcontrols View Post
    You should have everything you need with the browser interface. Really depends on user permissions and the NAV file. At this point I would delete the link from the link sheet and recreate it on the RF. Then comes the question if the program is what they want. Normally the AHU controller would be scheduled with the OCC-C point. This allows the ZN-T to cycle the fan at night plus some other stuff. If all they want is the fan s off, then what they have will do that. The real problem may come if the controller were to go into shutdown or unoccupied mode with the fan scheduled On. As they say "unexpected results may occur".
    I tried to have the schedule tag the OCC-C point and and the fan would not start from the schedule.

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