Water Sensor Recomendations

[snmhanson]

We are getting towards the trim out of a new construction and I need to install water sensors soon.  They are going to be located under/behind the dishwasher, built-in freezer, and two wash machines.  My plan is to wire them to our security/automation panel (most likely an OPII) and have the panel control the water shutoff valve (thinking an Elk WSV2).  Some of the sensors might be difficult to access once the appliances are installed so reliability and durability are both important factors.  Any advice as to which sensors I should get?  Also, if there is a better way to do this than what I'm planning I'm open to suggestions.
 
Thanks!
 
Matt

 

[RAL]

Water sensors are probably the best way to detect leaks.  There are also water flow sensors as another option, but in my opinion it's very hard to determine what is normal flow and what is not.
 
GRI makes several types of water sensors.  You can choose "spot" sensors like the GRI 2600 or "rope" type sensors, like the WM2600.

 

[snmhanson]

<p>Thank-you RAL.&nbsp; I think the GRI2600 looks just about perfect for what I need.&nbsp; I'll probably go with that.<br />
&nbsp;<br />
One additional question. I would like a valve that does not require power to remain open or closed - rather just a momentary relay from the automation panel that will open or close the valve. And ideally, it would be nice to use two relays - one that will open the valve and separate one that will close it. That way monitoring the valve position and programming for it won't be necessary or at least not as important. I can't tell for certain if the Elk valve offers both of those features or not. Can someone clue me in on whether the Elk will work for that, or if there is a different recommended valve to use? If separate control for open and close isn't possible then I guess I would want a valve that can at least indicate whether it's opened or closed.<br />
<br />
Thanks,<br />
<br />
Matt</p>

 

[RAL]

The Elk valve remains in its position until activated to open or close. It doesn't automatically close if power is lost.  You can continue to apply power to the open or close inputs after the valve has reached its limit. This allows it to be operated by a single SPDT relay, though you could use two separate relays if you wanted.
 
The valve has a status output wire which goes to +12V when the valve is closed.  It's not exactly what you want for monitoring with a zone input on an alarm panel. You'll need to have it operate a relay and then connect the relay contacts to the panel.
 
A similar valve is available from Greenfield Direct.  Their valves have a Form C (SPDT) contact output for monitoring status.  That eliminates the need for a relay as with the Elk valve.  Although the valve remains in its position if power is lost, the control to open or close it works differently.  You apply a trigger signal to the control input to open the valve and remove the trigger signal to close the valve. 
 
If you go with the GRI 2600 contacts, make sure you buy the 12V version and not the 5V or 24V.
 
There are some cheap valves that you can find on Amazon.  My advice is don't bother. I ordered one and found them to be junk quality.