Current Flowing Sensor - recommendations?

[NeilD]

I would like to ask the forum for a recommendation of a sensor. 

I have a fire suppression sprinkler system in my home (don't get me started ranting on why my town's building code requires it  ).  The controller has a 110V cable connection to an exterior alarm.  I would like to have my Vera Secure controller be able to trigger scenes when (a) that alarm has been triggered (b) the alarm has stopped.   I would prefer to not do this with a device that senses the sound or light of the alarm, as I don't want to have to climb a ladder for battery replacement etc.

Is there a sensor device that can be connected to the circuit between sprinkler controller and its alarm box that will raise an event to Vera when current flows in the circuit between the sprinkler controller and the alarm box?  I have access to the junction box, so I can either connect to the wires of the circuit or sense current flowing through the cable sheath.

Pretty sure I can hack this by dismantling an inexpensive current detector (the electrician's tool that lights an LED when you hold it over a hot cable) to control a relay connected into some other sensor, but thought I would check to see if there's a commercial device, or if others already have a hack for a similar problem.

Maybe relevant, the Vera and sprinkler controllers are in the same closet so a wired solution is an option.

I'm going to need something that's highly reliable, as this will ultimately result in the fire department being called to the property.

Thanks in anticipation!

[therealdb]

Isn't a normal switch what you want? I have a couple sensing external inputs (ie sprinklers, gates) and it's working very well. The only annoiance is the icon, but I wrote a custom device file that I can share.

[zedrally]

Use a dry contact relay so there is no possible voltage conflicts.

[NeilD]

@therealdb - Not sure exactly what you mean by a normal switch.  Are you saying to add a light switch into the circuit for the alarm, as if it were a lighting circuit with two switches - one triggered by the sprinkler system arming, the other can be manually triggered?  I guess that may be possible, though I would need to think it through carefully that this was an isolated alarm circuit and turning the switch on does not have the reverse effect of turning the pump on!  I would prefer to have something that just monitors the state of the circuit and has not means of altering the state of the circuit.

@zedrally - I will look into the dry contact relay.

Thank you both for your replies!
Neil

[zedrally]

Your other option (but possibly more expensive) is to use a Smart Energy Meter to monitor current.
I can't give you any solutions for monitoring Voltage or Amps as Vera doesn't support them (Homeseer does), you possibly could use watts.


Have a look over the link to get an idea of what I mean, it might give you an idea on what could be possible and narrow down the options.


Warning blatent plug below.....


https://www.blackcatcontrolsystems.com.au/Black-Cat-Smart-Power-Energy-Meter

[rigpapa]

Coming a little late to the discussion, but I used a bunch of these in data center controls applications:

https://www.nktechnologies.com/current-sensing-switches/

These are the real deal. You can get them as switches (current on = switch closed, or current > limit = switch open or closed), or as measurement devices (0-10v, 4-20ma, etc.). The AS1 was the go-to for our applications. Get the split-core model--you don't have to pull or splice the cable to get it into the CT, it just hinges open and you put it around the cable like a clamp meter.

I know that the older Aeotec door sensors had an auxiliary contact you could use. I use one on my smoke detector loop (Kidde SM120X connected to the door sensor aux circuit). Dealing with the door sensor batteries is a pain, though. But you just wire it straight to the current switch and Bob's your uncle.

[zedrally]

^^^^
I like the look of those, thanks for the heads up....

[NeilD]

Great contribution from all here - really grateful for the ideas.  Combining your ideas ... I think I've a multimeter with a clip-around sensor that I've never used - wondering if I can wire that into a Z-wave smart energy meter to create something akin to the Black Cat solution.  Will post here with anything I'm able to put together.

[therealdb]

@therealdb - Not sure exactly what you mean by a normal switch.  Are you saying to add a light switch into the circuit for the alarm, as if it were a lighting circuit with two switches - one triggered by the sprinkler system arming, the other can be manually triggered?  I guess that may be possible, though I would need to think it through carefully that this was an isolated alarm circuit and turning the switch on does not have the reverse effect of turning the pump on!  I would prefer to have something that just monitors the state of the circuit and has not means of altering the state of the circuit.

yes. I have a lot of Fibaro switches doing this kind of thing. they are mapped to
- my gate
- my garage door
- my doorbell
- a light sensor, to trigger external lights
- a PIR

Fibaros FGS 222 can by dry contacts (the gate and the garage door are based on this setup), while the PIR, light sensor and doorbell are 230v. it's basically like emulating a switch. I wrote some code to intercept the switch and run some code. I even managed to map my gate and my garage door like sensor (by writing back the appropriate variable) and I use them with the Garage Door plugin. The trick is to ignore the output and treat them like the switch.