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  1. #14
    Join Date
    Jan 2010
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    Quote Originally Posted by rundawg View Post
    Yes, one of those "Big as a House" package units - see attachment.
    Thanks, I probably passed right over it last night using a " Trane TEF " search. I did see that image searching.

  2. #15
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    Jan 2010
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    I see what you mean ...
    I wonder what the (eStage) is ?
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  3. #16
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    Jul 2007
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    Quote Originally Posted by VTP99 View Post
    I see what you mean ...
    I wonder what the (eStage) is ?
    From the manual I have:

    The High Efficiency, eStage option shall provide five stages of mechanical cooling with the ability to be at or below 25% compressor displacement at stage one.
    Instead of learning the tricks of the trade, learn the trade.

  4. #17
    Join Date
    Dec 2006
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    Vancouver, B.C.
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    I don’t think I’ve ever seen damper style head pressure control on a prop fan before. Whenever I see those damper controls they are on forward incline fans because they won’t overload the motor when the airflow is blocked.

    The other thing that makes little sense to me is it sounds like these backdraft dampers are susceptible to snow buildup holding them closed In the winter.


    Sent from my iPhone using Tapatalk
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  5. #18
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    Nov 2011
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    if you look at that manual RunDawg posted a pic of (RT-SVX34P-EN)...page 63-64-65 describes (in detail) the condenser fan staging. the pages before explain the compressor staging with and without lead lag enabled.

    there's also one line that describes shutting off outputs for 7 seconds to prevent windmilling of condenser fans. the way the OP described his dampers they are simply barometric (no actuator). if that's the case, they are there to prevent windmilling of fans in the off cycle. he will have to read the staging sequence and see if his fans are cycling correctly.


    Regarding the mechanically actuated dampers Trane uses on their condensers: I was once told that they are a hold over from the days of recip. compressors on their units. they prevented large pressure swings and oil issues created by ON/OFF fan control. once they switched to scrolls, the dampers remained for some reason....even though they weren't really needed anymore. if you have some with damper actuators, the control box for them is usually stuffed behind the main electrical panel, and is a PIA to access. and it's always a good idea to cycle them on a PM....most of them are ignored and actuators fail, or the dampers seize up.

  6. #19
    Join Date
    Mar 2018
    Location
    Florida
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    Thread Starter
    That is it right there. so if you look at that picture the two fans all the way to the right have the louvers.
    ( I would describe these best as the louvers on a dryer exchust). the fan buy its self is number 3 and is the last to turn on, so while its off its spinning backwards due to the air bypassing the coil.

  7. #20
    Join Date
    May 2014
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    Bay Area California
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    It's also very likely head pressure control was added to the unit, but whoever installed it, didn't have a clue how to hook up the actuator for the louvers. So they were never installed. Used to see those head pressure activated actuators all the time. Decades ago. Haven't seen one, oh wait, there is one account we have that still has one. Brought back memories of when I didn't have a clue what was going on.

    Trane was good about head pressure control. Back in the day when others were not good.

    I wouldn't be the least bit surprised if that fan with no louvers was (intended to be) on an outdoor ambient control. Maybe something like turn the fan on at 75*F and off at 65*F. Then the two other fan louvers were intended to be controlled by head pressure.

    It would depend on the age of the unit. I've never seen only barometric dampers on the outdoor fan motors. So if it's an old unit, chances are those louvers were never installed proper. If it's a newer unit, then Trane is controlling the outdoor fan motors differently, through the electronics of the OA and saturation temps.
    If you were a real tech, you'd solder a relay on that board and call it good to go.

    I do a triple evac with nitro to remove non condensables.

    I use 56% silver on everything except steel.

    Did you really need the " If you were a real tech " ??

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