Forum Discussion

deprived's avatar
deprived
Explorer
Apr 05, 2017

two-wire? three-wire LPG detector connector? what?

Our old LPG detector finally went insane recently (it was very, very old) . The house and coach batteries were fully charged, so I am certain that was not the issue. It was a ten-year old unit.

Anywhoozle.

The new detector has two wires (power, ground). The old unit had three. According to this schematic from Fleetwood, it appears that my old detector was part of a solenoid cut-off. Or something. I totally suck at reading schematics and diagrams.

Rather than not have ANY detector, I just connected the new unit to one of the hot wires from the old detector. It seems to work fine (I let the stove spew propane just to test it) but I can't help but be bothered by the fact that I may have bypassed some kind of safety by ignoring the original three-wire setup.

Does anyone here have any experience with this situation? What did you do?

THANKS!!!

  • enblethen's avatar
    enblethen
    Nomad
    Apr 05, 2017
    My earlier LP detector put the solenoid in series with the ground connection.
    My replacement fro Safe T alert, a combination LP detector and co2 sensor does not. It requires you connect a relay input to the in coming power. Then the relay sends power to a new solenoid. Safe T alert says that the original solenoid would not handle the full 12 volts put out by their detector.
    Do you see the make of your old detector?
    What is make and model of new detector?
    Look at the solenoid next to your LP tank and check wiring from detector.
  • enblethen's avatar
    enblethen
    Nomad
    Apr 05, 2017
    I will add that your drawing does not show the solenoid. Mine was in series with the yellow lead going to the ground connection.
    I used the red wire from the chassis system to feed the detector and capped off the one from the chassis system.
    New detector has four wires.
    This is your old one CCI
    This is the one I installed Safe T alert
  • road-runner's avatar
    road-runner
    Explorer III
    Apr 05, 2017
    In my rig, the two power wires are so the detector is powered by the chassis battery when the ignition is on (driving), or the coach battery/shore power when the coach is powered (camping). You could accomplish the same thing with a diode from each power source connected to the detector's power wire. I'd expect that's what's inside the 3-wire detector.
  • loggenrock's avatar
    loggenrock
    Explorer
    Apr 05, 2017
    Educated guess here - since it is a LP detector, it could have turned off the flow of LP into the rig when it activated. Not all rigs had such a system - so even though your original detector had 3 wires, it might not have functioned that way. Check the LP line from the tank - if you find an in-line electric valve, there's your answer. As long as you have propane flowing, based on your test, i'd think you are all set. ST
  • RLS7201's avatar
    RLS7201
    Explorer II
    Apr 05, 2017
    Your old detector is probably a CCI 7719. CCI went out of business in 2008. The 2 red wires go to your 2 battery banks. The yellow wire goes to the solenoid/valve. The coil on the solenoid/valve is 9 volts DC @ 168ma. If you keep 12 volts applied to the coil for an extended period of time, the coil will burn out.

    1: You can remove the solenoid valve and replace the detector with a cheap 2 wire detector. You will then loose the capacity of the detector turning off the propane in case of a leak.

    2: You can purchase a 3 wire detector, with 12 volt solenoid valve @ 1 amp, from Safe-T-Alert. for about $200 on Ebay.

    3: Your CCI 7719 is repairable. Contact Larry at CCIRepairs@gmail.com for details. I have one of Larry's repaired detectors on my 95 Bounder. It's been flawless.

    Richard
  • deprived's avatar
    deprived
    Explorer
    Apr 05, 2017
    RLS7201 wrote:
    Your old detector is probably a CCI 7719. CCI went out of business in 2008. The 2 red wires go to your 2 battery banks. The yellow wire goes to the solenoid/valve. The coil on the solenoid/valve is 9 volts DC @ 168ma. If you keep 12 volts applied to the coil for an extended period of time, the coil will burn out.

    1: You can remove the solenoid valve and replace the detector with a cheap 2 wire detector. You will then loose the capacity of the detector turning off the propane in case of a leak.

    2: You can purchase a 3 wire detector, with 12 volt solenoid valve @ 1 amp, from Safe-T-Alert. for about $200 on Ebay.

    3: Your CCI 7719 is repairable. Contact Larry at CCIRepairs@gmail.com for details. I have one of Larry's repaired detectors on my 95 Bounder. It's been flawless.

    Richard


    Well, yeah! I tossed the old detector, figuring there was no difference between the new and old. (what did I know?) That said, 200 bucks for a replacement ain't happening!!

    I'm okay with the solenoid being removed from the setup. Eventually this was abandoned and I'm beginning to see why. Good idea, more or less. But more less.
  • dougrainer's avatar
    dougrainer
    Nomad
    Apr 05, 2017
    3 wire LP detectors that had a 12 volt solenoid were common years ago. But, OEM's and Rver's got tired of false trips that caused loss of LP when the LP solenoid shut down. There is NO code that requires an LP detector shut off system. So, when the original LP detector failed you installed a standard LP detector and REMOVED the 12 volt solenoid at the tank regulator.
    There are 2 types of 3 wire LP detectors.
    1. The one with the cut off solenoid as above
    2. The other uses a positive wire from the coach AND a positive wire from the chassis to make sure the unit always had power. Doug
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Apr 05, 2017
    Yup, you bought the wrong detector.

    Many RV's have the Detector shut off the propane via a solenoid if it is either
    A: Turned off or
    B: Alarming.

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