Hook Up Alarm to A/C Condensant Overflow

Discussion in 'General Electronics Chat' started by dw85745, Oct 7, 2015.

  1. dw85745

    Thread Starter New Member

    Oct 5, 2015
    I bought a Rectorseal SS1 which is basically a float that is normally closed.
    Its' purpose is to shut of the A/C when the pan is about to overflow (i.e. water is detected.)
    Haven't installed it yet so not sure what the voltage is on the Red / Yellow Wire that goes to the thermostat.

    I also have an alarm for my Water Heater and other Water Overflows.
    The alarm is Normally open and only triggers if water is detected. (switch closes).

    What i want to do is wire the float to the alarm I already have such that the alarm will trigger when the SS1 opens.
    I thought I might be able to use some kind of digital invertor that would change the normally closed to normally open and
    vice-versa so the float operates as designed, but it will sound the alarm when if opens (water is detected).

    1) Will a digital invertor work (with some resistors) work if the A/C thermostat voltage is > 5 volts (my guess probably 12 or 24 volts)
    2) Is there a better way -- without getting into a complicated circuit design -- and if so what?

    Last edited: Oct 7, 2015
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    Just connect your alarm (a Sonalert buzzer, for example) across the two wires of your switch. When the switch is connected and your AC is running, nothing will happen with your alarm because the two wires of the buzzer are shorted together by the switch.

    The same company sells a switch for this purpose. I would buy that one so it all works together. If the alarm draws too much current, it could cause the AC to stay on.


  3. dw85745

    Thread Starter New Member

    Oct 5, 2015

    Was aware of the SG1, just figured I could use my other alarm where I have all alarm circuits terminating.
    Having a single end point I no where to go if an alarm and at that point can ID which alarm triggered -- see working on best way to ID which line set off the alarm.
    -- right now alarm works great if each line goes high (switch closes).

    Guess I have to do some more research to see when the red wire triggers.
    Per above diagram looks to me like the alarm would trigger each time the unit shuts off.