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  1. #1
    Join Date
    Dec 2001
    Location
    Cartersville Ga
    Posts
    1,035
    new unit, builders grade bryant 80% furnace, 10 seer cube, bryant digital non programmable tstat. heat works fine, cooling is giving me fits!

    fan in ON works
    nothing from Y to C at board with call for cool
    stat was changed, including sub base
    g and y were swapped to rule out wire
    stil the same
    jump r and y at the board, fan comes on like it should
    removed Y from board, NOW have 24 from wire to common, hook it up, lose it
    board was changed
    still the same problem.

    there is a short some where, but where?
    o/d wires were disconnected during this "episode"

    it was monday morn, first call, i am sure i am missing something, but still not sure what!

    thanks for any input


    In the land of the blind the one eyed man is King! semper fi

  2. #2
    Join Date
    Apr 2004
    Location
    Maryland
    Posts
    522
    check to make sure there are no safety switches wired in series with y or R. ex. float safety switch, condensate pump safety switch etc. Check Tstat wiring. Make sure Yellow wire is on terminal that says y/y2 (think that tstat has two different y connections. I could be wrong. Did you try jumping R and Y at tstat (contactor should pull in)

  3. #3
    Join Date
    Dec 2001
    Location
    Cartersville Ga
    Posts
    1,035
    has a pan switch, took it out, all wires are correct, did not ump R any Y at stat

    thanks

    mike
    In the land of the blind the one eyed man is King! semper fi

  4. #4
    Join Date
    Jul 2004
    Location
    midwest
    Posts
    2,868
    Its not a short or you would blow a fuse or the transformer. What happens when you connect R and Y at stat? Sounds like the stat is wired wrong.

  5. #5
    Join Date
    Jul 2004
    Location
    midwest
    Posts
    2,868
    Man i'm a slow typer. If you can jump R and Y at the board and it works you rule out everything but the stat and wire feeding it.

  6. #6
    Join Date
    Dec 2001
    Location
    Cartersville Ga
    Posts
    1,035
    you are exactly right, it has to be the wire, i suspected it (why i swapped g and y) but ruled out stat for sure.


    thanks

    mike
    In the land of the blind the one eyed man is King! semper fi

  7. #7
    Join Date
    Jul 2004
    Location
    midwest
    Posts
    2,868
    If you have a bad connection or broken wire you will get 24 volts on it until you put a load on it.

  8. #8
    Join Date
    Jan 2004
    Location
    PA
    Posts
    68,769
    Originally posted by trane
    If you have a bad connection or broken wire you will get 24 volts on it until you put a load on it.
    what trane said.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  9. #9
    Join Date
    Jul 2004
    Location
    West TN
    Posts
    983
    Did you wait for your thermostats cycle timer to time down?

  10. #10
    Join Date
    Jul 2004
    Location
    midwest
    Posts
    2,868
    Originally posted by wormy
    Did you wait for your thermostats cycle timer to time down?
    Thats a good point but I don't think he would have 24 volts with the wire unhooked if this was the problem. I may be wrong, I guess I have not ever checked to see.

  11. #11
    Join Date
    Nov 2001
    Posts
    1,874
    I had a similar problem several yrs ago, The 2 wire outside was bad.
    It wouldn't handle the load, but showed to be good as far as ohm's.
    Ran new 2 wire, and all was well.
    If you try to fail, and succeed.
    Which have you done ?



  12. #12
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,516
    check all the low voltage wiring in the unit
    if the 2 wire to the cu is off the board and no voltage between y and r while connected to the board. then something in the circut is drawing down on y
    conld be a bad ground to the board. y is shorting somewhere in the unit and not when you remove it from the board. comon is crossed . try going directly to the condenser with y and see it it comes on if so go back to the control and trace the low voltage wires through all circusts. maybe a wire fell off at install and the guys put it in the wrong place

  13. #13
    Join Date
    Dec 2001
    Location
    Cartersville Ga
    Posts
    1,035
    have not been back to job yet but had it happen again on an identical system today.

    changed stat first, then with same issue jumped r and y at stat, unit ran

    installed a W/R stat instead of the bryant digital nonprogrammable, and unit is running fine.

    even got the replacement stat from next door where it was working properly!

    huh?


    mike
    In the land of the blind the one eyed man is King! semper fi

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