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  1. #1
    Join Date
    Dec 2005
    Location
    California/Nevada
    Posts
    3,729

    Troubleshooting Zoning :)

    Most of the companies i worked for wouldn't troubleshoot zoning.
    (we do things a little differently out here in L.A.)

    now i'm at a company where knowing it sure would help.


    i've read about how zoning is supposed to work, but troubleshooting is a different story

    (i also have info for Carrier Infinity type zoning)
    --------------------

    had a problem at a house where the upstairs dampers were closed with both upstairs and downstairs t-stats calling.

    a tech told me one time, the way to check a damper is to slice open the duct and put your hand in there.
    i didn't want to do that.
    1) is that a standard proceedure?

    2) is the duct with the alan wrench adjustment the bypass?

    3) does every zoning system require a bypass?

    4) what would you estimate the frequency is of having to replace a control board?

    5) are most dampers spring open , 24v power closed?

    6) i replaced a small circuit control board that seemed to be milivolt. are those common now?

    7) what are the most common problem?





    thanks

  2. #2
    Join Date
    Dec 2010
    Location
    The Quad-Cities area (midwest).
    Posts
    2,744
    I'm not a service tech (and I haven't slept at a Holiday Express lately) but I've sold zoning. In our area, most dampers are spring open, power closed. No, all systems do not require a by-pass damper. I don't understand your question #2.

    You don't need to tear into the duct, the motor (which is probably the problem) should be serviceable from the outside.

  3. #3
    Join Date
    Nov 2011
    Location
    USA
    Posts
    406
    Quote Originally Posted by George2 View Post
    I'm not a service tech (and I haven't slept at a Holiday Express lately) but I've sold zoning.

  4. #4
    Join Date
    Dec 2010
    Location
    The Quad-Cities area (midwest).
    Posts
    2,744
    Thank you. I try to keep it light or else we would go crazy in this business.

  5. #5
    Join Date
    Jan 2007
    Location
    Stongsville Oh
    Posts
    948
    The bypass damper is a way to control duct static pressure and to provide adequate flow across a cooling coil or furnace heat exchanger. Along with this the system has a discharge air temp sensor that will cycle compressors or heat to provide a reasonable supply air temp such as 55°F for cooling mode and 120°F for heating. Bypass air keeps recycling, as zone demand increases static pressure in the duct drops ( a zone damper opening) bypass damper throttles closed a little. Get the manuals on the systems that you plan on working with and read sequence of op. until you are comfortable.
    ckartson
    I didn't write the book I just read it!

  6. #6
    Join Date
    Jul 2013
    Posts
    48
    A bypass will always help but you can size the ductwork to work properly. I use Honeywell dampers and they are power open and spring closed but I also use ewc dampers and they are powered open and close. The most common problem is undersized ductwork with no bypass and they make bypass dampers that are controlled by a weight according to static pressure.

  7. #7
    Join Date
    Mar 2004
    Location
    SE Michigan
    Posts
    18,223
    Aint no thang but a chicken wang.
    To put the world in order, we must first put the nation in order; to put the nation in order, we must put the family in order; to put the family in order, we must cultivate our personal life; and to cultivate our personal life, we must first set our hearts right.
    -- Confucius

  8. #8
    Join Date
    Dec 2005
    Location
    California/Nevada
    Posts
    3,729
    what do the duct temperature sensors do?
    shut down the whole system?

  9. #9
    Join Date
    Sep 2013
    Location
    none of your ****ing business *******
    Posts
    7
    Carrier Infinity does not require a bypass.

    DO NOT USE a bypass damper with the Infinity Zoning
    System. Addition of a bypass will cause improper operation.
    Airflow management will be performed by the User Interface
    algorithms. The User Interface will monitor the system and
    will maintain proper airflow through the heating / cooling
    equipment. (excerpt Carrier Install/Start-Up Instructions)

  10. #10
    Join Date
    Aug 2008
    Location
    San Clemente, CA
    Posts
    1,243
    Quote Originally Posted by wolfstrike View Post
    what do the duct temperature sensors do?
    shut down the whole system?
    Cycle outdoor unit based on supply air temps in cooling and cycle furnace based on temps. If I was you I would look into some online training with Honeywell. Then you could move onto OEM systems like Lennox Harmony III. A good background in system design would help you when it comes to troubleshooting.

    I just had a 14" Honeywell zone damper (spring open) not opening. When I replace it I am going to add 3' of KD to get it further away from the plenum. This is recommended in installation instructions to balance the air pressure load on this large damper blade. I McGyvered the damper in the open position to give this zone some A/C till we correct this.

    Get some install instructions and do some nighttime studying. It will help to put you to sleep.
    Inventor/Manufacturer:
    KoppLift™ Hand Truck Lifting Bar
    http://www.amazon.com/shops/JohnGKoppLLC
    Video
    http://youtu.be/FsSViwAEz7A

  11. #11
    Join Date
    Sep 2013
    Location
    none of your ****ing business *******
    Posts
    7
    Get some install instructions and do some nighttime studying. It will help to put you to sleep.

    I have some VVT books if you need a deep sleep....lol

  12. #12
    Join Date
    Jun 2011
    Location
    Central Indiana
    Posts
    617
    These answers apply to most zone systems, I have very little Infinity experience though. This is for residential/light commercial zoning. Commercial zoning, micro-control zoning, VAV and VVT is and whole 'nother bowl of cereal and more complicated than could ever be contained in one post.

    Determine what kind of damper your working on. The most common I see are spring open/power closed and power open/power close. The SO/PC requires 2 wires, and is referred to as a 2 wire damper. The PO/PC requires 3 wires and is referred to as a 3 wire damper. Once you have determined which damper your working on, determine if the board is sending with correct signal for the correct call. All dampers I have worked on are 24v and almost every system requires a designated transformer so keep that in mind.

    If you have the right signal, locate the damper. Everyone I have ever looked at has some sort of index to let you know what position it is in. Reference the index. If its unclear, slide the damper out of the ductwork and look at the blade. Usually they are held in by a couple screws and slide out.

    If the motor is getting the right signal and not doing as it should, replace the damper.

    If your not getting the correct signal, there are three things that could be going on. The stat could be faulty, not calling like it should, so check the signal from the stat.

    The board could be sensing a high or low limit. This is pretty specific to each board so you will need some info on the board but most use a 10k thermistor so that could be bad. But generally, a high or low limit will activate all the dampers to try to fix the limit trip and call for blower. So over cooling or over heating is a more likely out come of this failure.

    The third option is that board is bad. If the relays in the board fail, over shooting or under shooting can occur.

    A bypass is needed to prevent a low air flow situation when smaller zones are calling alone. There are weight controlled static pressure dampers, preset motorized dampers that are activated by the board, or stand alone static pressure sensing motorized dampers. Heating or cooling issues that present as low air flow issues when only one or less than all zones are calling may signal an issue with the bypass. Such as improperly adjusted or stuck closed. High return temps in heating, or low return temps in cooling can indicate a damper that is stuck open. Also open and closed are relative things so it doesn't have to be stuck all the way open or all the way closed to cause problems. Zone board limit trips often indicate bypass problems.

    Zone systems can seem overwhelming, but if you break it down there are really one 3 parts, the board, the dampers and the bypass. Step by step process of elimination will fix every problem you every come across.
    The only true knowledge is the pursuit of knowledge

  13. #13
    Join Date
    Jun 2012
    Posts
    38
    This may help if you don't already have

    http://www.docs.hvacpartners.com/idc.../zone-01dg.pdf

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