Help with Gas Detector Install

[ericscales]

Hey folks.  I bought this cheap gas detector to put in the basement near the furnace and hot water heater.  Either it's broken (oh well it was $14) or I am baffled by figuring out how to hookup a relay.

 

I've attached a scan of the install guide (which is hilarious to read through if you want a laugh).  Anyhow, here's the deal.

 

The wiring is as follows:

• Black -> GND
• Red -> DC12-24V
• White and Blue -> NO
• Blue and Green -> NC

I tried hooking this up on an HC-250 to test.  Now my assumption is that I use the HC250 contact input, plug the black into GND, the red into 12V, and either the white and blue wires (for normally open) or the blue and green wires (for normally closed) into the SIG (signal input).  I tried this, and the device powers up fine.  I put it on a propane grill, turned on the gas, closed the lid and left it for a few minutes (I could smell gas) and nothing - I don't see any change on the contacts..

 

Thoughts?

 

Sg-2008h install.pdf

[mstafford388]

This install guide is pretty funny.  I'd pull that thing off the controller and use a continuity tester on the normally open wires if you have one just to verify that thing works.  

 

Are you putting both the with and blue or blue and green into the sig?  if so that won't work.  not sure if you just typed that wrong or if i'm reading it wrong.

[SMHarman]

"Carefully remove all children and not related people from that area"

 

Relatives can burn...

 

LOL

[ericscales]

This install guide is pretty funny.  I'd pull that thing off the controller and use a continuity tester on the normally open wires if you have one just to verify that thing works.  

 

Are you putting both the with and blue or blue and green into the sig?  if so that won't work.  not sure if you just typed that wrong or if i'm reading it wrong.

 

Thanks for the help.  I will do a test.  I am putting both into the sig.  How should I wire it properly?

[mstafford388]

Since you wired up the power part and it worked leave that the same way, or you can just use a power supply.  Then if you put the white and blue wires into the NO and C in the relay you should be all set.  You'd have to add a generic relay into programming and connect that to the relay port on the 250.  Then all of your programming is done off of the relay opening/closing.

[ILoveC4]

Why mess with your BBQ?  The instructions clearly say "Monthly checking if equipment can work well by pushing a little gas from a cigar lighter near the ventilation slots.".

[ericscales]

Since you wired up the power part and it worked leave that the same way, or you can just use a power supply.  Then if you put the white and blue wires into the NO and C in the relay you should be all set.  You'd have to add a generic relay into programming and connect that to the relay port on the 250.  Then all of your programming is done off of the relay opening/closing.

 

Ah, thank you!  I'll give the relay ports a try.  Don't forget to watch the news tonight to see if a south denver neighborhood was evacuated due to a "gas leak".

[RyanE]

I'd guess the blue is the 'common' wire for both the NO and NC outputs, so one of those outputs connects if there's no gas sensed, the other if there's gas sensed.

 

I'd test continuity between the blue and green, it should show continuity, if there's no gas.

 

I'd test for continuity between blue and white.  It should not show continuity, unless there's gas.

 

If that's the case, and it's a dry relay output as it appears, you should hook blue to +12V, and the white to your contact input on a controller or other device.

 

RyanE

[RyanE]

And to clarify, this device provides a *relay output*, not a relay input, so you don't hook any of these wires to a Control4 Relay, but to a Contact.

 

RyanE

[ericscales]

And to clarify, this device provides a *relay output*, not a relay input, so you don't hook any of these wires to a Control4 Relay, but to a Contact.

 

RyanE

 

Gotcha.  Thank you.

[RyanE]

Oh, and I almost forgot the obligatory CYA...

 

Disclaimer: If you fry your device, or your Control4 equipment, or burn your house down while trying to sense a gas leak, don't blame me...

 

 

RyanE

[CFUG]

Sensitivity of 10%? NG has a LEL of 5%.  The unit won't respond until 10% of LEL is reached.  Granted, 10% is not what I'd call property-threatening by itself.  But, if the ignition source is in the immediate vicinity of the pocket of concentration, boom.

 

I don't have any experience with low-cost IR units (this one appears to be IR) but one problem with this is that it only looks at small space between the reference beam and the detector which means the entire room might need to be at 10% LEL for the sensor to react. 

[ericscales]

Sensitivity of 10%? NG has a LEL of 5%. The unit won't respond until 10% of LEL is reached. Granted, 10% is not what I'd call property-threatening by itself. But, if the ignition source is in the immediate vicinity of the pocket of concentration, boom.

I don't have any experience with low-cost IR units (this one appears to be IR) but one problem with this is that it only looks at small space between the reference beam and the detector which means the entire room might need to be at 10% LEL for the sensor to react.

So how long would I need to leave my gas grill on (just the gas running), lid down with this little bastard inside? Maybe I just never let it go long enough.

Sent from my iPad using Tapatalk HD

[CFUG]

^That test should work fine.  Ohm meter set to audible, probes on WHT and BLU, wait for the tone.  I see on ebay several chem cell units for around $100.  These all have 4-20 (no C4 use for that) and contact closure.