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Wiring float switches

Discussion in 'Residential' started by Zman, Feb 27, 2017.

  1. Zman

    Zman Hanging by a Thread

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    Location:
    The "I know a Guy" State
    Had a minor argument with a senior tech a while back on best way to wire a float switch.He says as usual,break power to condensor.I say why not break both through power(R)from tstat.Why? Well let's say Homeowner turns a/c on ,on way out the door to go to work,wants it's cool when they return,hears fan,assumes all is well,but comes home to a steambox ,drained was blocked from previous day.But my way the indoor Blower never comes on,so they make a call immediately instead of finding out at 5 o'clock.Or at very least,opens some windows!
     
  2. Swampfox

    Swampfox red tagged

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    chocolate or vanilla

    a decent argument can be made to do it either way
     
    Texas-Tech, Joe5 and jrbenny like this.
  3. Swampfox

    Swampfox red tagged

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    one might say....the negative pressure from keeping the blower on helps keep a flooded air handler from dumping immediately
     
    mike1020 likes this.
  4. mike1020

    mike1020 entitled millennial

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    +1

    Float switch trips before water starts to leak.

    Fan shuts off, water settles and overflows pan.

    I've seen this happen when you get to a unit with a plugged drain, you turn off the unit, fan stops, and the great flood begins.
     
  5. Jim54

    Jim54 New Member

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    Hmm. (On residential installations) In addition to a float switch on the emergency drain pan our local codes require a condensate drain line from the emergency pan to the soffet just above the living room or kitchen window where it will be noticed by the homeowners.

    The condensate drain line from the evaporator goes to the sanitary waste and sewer system and must be trapped. We usually broke Y1 but I see nothing wrong at all with breaking R as it offers the advantages you mentioned.

    On commercial installations like conference rooms and server rooms the emergency pan sometimes drained to a janitors sink or a hub drain and sometimes had no drain line, so the float swith was a very important early warning of trouble. We also had deep heavy gauge pans specifically made for our AHUs and never ever used perforated plumber's strap. Our shit was always over built.
     
    Last edited: Feb 27, 2017
  6. Zman

    Zman Hanging by a Thread

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    Good reasoning on the Negative pressure helping to hold back some condensate,and the customs made deep pan is smart.So I figure the electronic Hockey Puck style water sensor is better than a float,as it would shut down the system at first detection of water!
     
  7. doc havoc

    doc havoc A cunning linguist

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    Breaking R will also kill the heat. Frozen/busted water lines would make a hell of a lot bigger mess than some condensate overflow. Just another piece of the puzzle to consider.
     
  8. Daryl_Dixon

    Daryl_Dixon New Member

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    3,672
    Yep.

    When there's a problem with the AC, I don't want to lose the ability to run heat or blower.

    Shitty drainwork and a lack of redundant overflow protection like a secondary pan is just bad install.

    Could wire a unit to open Y and close G upon overflow switch trip.

    Hmm..

    Where I currently work, it's considered very bad form to "disable" more than needed from a machine. We see guys who kill the disconnect when there's a bad heat exchanger. Now the unit has no ability to cool, to circulate, to monitor for smoke, or to communicate with EMS. Rather, it's better to remove W-1 and W-2 wire from terminal strip, possibly unplug the inducer motor and shutoff the CGV switch, and tag out the gas.
     
    mike1020 and doc havoc like this.
  9. Daryl_Dixon

    Daryl_Dixon New Member

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    And I forgot to mention...for the love of all that is good and true in the universe...leave a conspicuously placed note in the unit. :D
     
    Rather B Riding likes this.
  10. Catpower

    Catpower The Crowd Pleaser

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    I have run into that shit so many times, that the drain plugged up and it dripped on the patio or outside a window and the dumb **** HO just keeps running the unit until the emergency pan rusts out or plugs

    Hey dipstick did you notice water dripping from someplace it shouldn't be or never has before:damnit::damnit::damnit::damnit:
     
    Jim54 likes this.
  11. Jim54

    Jim54 New Member

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    254
    Location:
    Addison, Tx.
    Yes, I've seen HOs not realize what that water draining in front of the window meant once or twice....:D.
     
  12. R2D2-TX

    R2D2-TX New Member

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    414
    I have had customers call and said that there must be something wrong with their drain because it is not draining outside like their neighbors drain.......


    Sent from my iPhone using Tapatalk
     
    Texas-Tech likes this.
  13. jamesyarbrough

    jamesyarbrough Amateur Gynecologist

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    Always break y. No need to kill the whole thing. ...unless its a 90% furnace.
     
  14. otto

    otto Bakery Chef

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    I used to break C to the condenser and humidifier, otherwise just Y. Up here near Chicago you don't want to disable the heat.
     
  15. LemonWizard

    LemonWizard Blinky Lights Wizard

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    Location:
    Ohighyo
    And there are plenty of places that are 70+ in the daytime and in the 30s or 40s at night at certain times of year.
     
  16. Daryl_Dixon

    Daryl_Dixon New Member

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    Yep, it was 60 this morning and it's 24 now.
     
  17. ZipfelNm1

    ZipfelNm1 New Member

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    Last edited: Sep 9, 2017
  18. chucko615

    chucko615 Banned camp counselor

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    14,409
    Location:
    Michigan
    Zip please start a new member thread and introduce yourself.
     
  19. Rather B Riding

    Rather B Riding Behind bars

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    Always break only Y. It has happened more than once. Someone changing filters bumps the float crooked and now there's no AC. Better than causing a no heat call.