Results 1 to 9 of 9
  1. #1
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,075

    Intellipak/Statictrac

    Intellipak with Lon-Discharge Air Controller-What would keep exhaust fans from coming on when Exhaust Fan enable setpoint is met?I know they are enabled on older Intellipaks at this setpoint reguardless of space pressure but I have some on a building that do not enable at setpoint.
    It might get loud!

  2. #2
    Join Date
    May 2000
    Location
    Stafford, Va. USA
    Posts
    213
    Hi Duke of Earl,
    You need to determine if it is the EMS or the RTU causing the problem,
    I would go into the Setup menu, and access the screen where the selection is made for "Remote" (EMS) control or "Local" (Unit) control. Select Local control and enter your selection. Then watch to see if the exhaust fans start to work.
    The things that you need to verify during this test:
    1. The outside air damper is open beyond the "Exhaust Enable Setpoint."
    2. The space pressure is higher than the setpoint by at least one half of the deadband.
    As an example, Space pressure setpoint is 0.03" and the deadband setting is 0.04,
    the space pressure has to rise above 0.05" wc.
    If the exhaust fan starts to work during this test, the problem is a setting in the EMS.
    Good Luck,
    Allen
    UA Local 602
    A man who says that he can't learn anything in a class is exactly right.

  3. #3
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,075
    Thanks Allen. The units I believe are in local control. Am I correct in thinking that The exhaust enable point is where the exhaust fan comes on reguardless of space pressure? I have always known Intellipaks to operate this way.
    It might get loud!

  4. #4
    Join Date
    May 2000
    Location
    Stafford, Va. USA
    Posts
    213
    Hi Duke of Earl,
    No, the exhaust enable setpoint is the position the outside air damper be opened to enable the exhaust "logic." The exhaust logic is looking at the space pressure setpoint and space pressure. Once the space pressure rises above the space pressure setpoint plus one half of the deadband setting, the exhaust fan will start. If the space pressure setpoint is 0.03 inches of wc and the deadband setpoint is 0.04 inches of wc, the space pressure would have to rise to 0.05 inches of wc before the exhaust fan would start.
    The exhaust enable setpoint is set to 25% from the factory. I would always lower it to 5%, especially in buildings that had multiple units serving a common area. This would keep the space from being overpressurized.
    Allen
    UA Local 602
    A man who says that he can't learn anything in a class is exactly right.

  5. #5
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,075
    This makes sense since these units are not reporting space pressure high enough to enable the fans. My problem must be in the sensing of space pressure. I will check with a digital manometer.I do have multiple units serving common areas so your advice will be tried. When I get it ironed out, I will get back with you and report the results. Great info Allen and I really appreciate your responses!
    It might get loud!

  6. #6
    Join Date
    May 2000
    Location
    Stafford, Va. USA
    Posts
    213
    Hi Duke of Earl,
    You are welcome.
    When you return to check the space pressure, be sure to tee in across the space pressure transducer so that you are reading what the transducer is reading.The space pressure sensing tube should be located on the first floor of the building, in a large common area such as the elevator lobby. The first floor would be the area where people would most likely sense any space pressure problems, being close to the exit to the outside of the building.
    Good luck.
    Allen
    UA Local 602
    A man who says that he can't learn anything in a class is exactly right.

  7. #7
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,075
    Great info Allen. This is the kind of stuff that is not in the IOM. I had another job yesterday with a space pressure issue (different than this one) and I teed in to the transducer which was reading .3 to .4 in.w.c. Traced the tubing and found it lying in the second floor ceiling unattached from the sensor fitting. I reconnected the tube and no change. I don't believe the actual pressure is that high. Still have to return and continue diagnostic.
    It might get loud!

  8. #8
    Join Date
    May 2000
    Location
    Stafford, Va. USA
    Posts
    213
    Hi Duke of Earl,
    The unit that you were working on that was operating with space pressure indication of 0.3 to 0.4 inwc, is it an older unit? From the late 90's. There were some units shipped out that had the space pressure calibration solenoid valve turned around backwards. This would cause space pressure problems.
    Also always make sure that the tubing to the "red bird" is free and open. No kinks, crushed or anything inside the tube to block it. I found a bug larva inside this tube once. Also check the 1/4" bulkhead fitting that penetrates the RTU casing, found one that was not drilled.
    There are many more horror stories, I am sure that you have many also.
    Good luck,
    Allen
    UA Local 602
    A man who says that he can't learn anything in a class is exactly right.

  9. #9
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,075
    Roger that! The new transducer we put in is defective. Got another one and it is working fine. The vintage is 2001 and it has worked fine until last week. On the first unit I posted about, I was there today.I changed the units from BAS to Local control and statictrac went to working. Put them back to BAS control and statictrac no workie. I think I'm on to something here!
    It might get loud!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event