Shutting off a well pump

I just installed some insteon leak detectors in my home and was thinking about installing a water shut off valve to stop flooding during a leak. However, it occurred to me that it may be easier (and cheaper) to just control the power to the well pump if a leak is detected. Would this be a good solution instead of a more expensive water shut-off valve?

The power to the pump is 220v, and there is already a manual switch to turn power off/on. So, I was thinking of the insteon 2477SA1 normally open relay. My assumption was that if power is lost (and i have a leak) power to the pump would stay off when power is restored - the ISY would keep it off until I reset using my ISY programming. Is this correct?

Would constant power on the relay to keep it closed (and the well pump powered) cause the relay to burn out after some time?

If it isn't a good idea to control power to the well pump in the case of a leak, my other option was to install GreenField Direct ASV075 3/4" Controlled Water Valve.

Thanks for any thoughts on this!
joe

If you have a well pump, you almost certainly also have a pressure tank that stores quite a few gallons of water and evens the flow into your plumbing.  The problem with shutting off power to the well pump is that your pressure tank could still deliver 20 or 30 gallons of water before the pressure drops enough to cut off the flow.  That's quite a bit of water to have where you don't want it.
 
If it were me, I'd go with the water shut off valve.

Good point. That didn't occur to me.

So, so i assume the shut off would be installed after the pressure tank? But, the last few leaks (minor) that i have was with the copper lines into the pressure tank.

Yes, generally, you'd put the shut off valve after the pressure tank.  If you really wanted some extra protection, you could go with both the relay and the shut off valve to protect against leaks on both sides.   But even with that, if you had a leak before the pressure tank, it could still allow the water in the tank to leak out, depending on the location.
 
If you have a check valve just before the input to the tank, that will limit the potential trouble spots where a leak could allow the tank to drain.  But there's always going to be a place (such as the tank itself) where there could be a leak that you can't completely protect against.

There was a few discussions on the UDI forums about this. Some will be able to inform you of many thoughts and applications tested.
 
I have a lot of PEX plumbing, including open circuit in-floor heating and the pressure would definitely pump out 10-30 gallons of water before the pressure subsided.
 
Putting a controlled valve after the pressure tank would definitely be preferable for less flooding but any method would be better than coming home to 26 inches of water in the basement.
 
Killing the pump and releasing pressure may be an option except for valve or control failure dumping massive quantities of water down the drain upon failure. PLM failures with the ISY tend to turn everything on so the failsafe mode would be a necessity = Insteon ON = valve off.
 
ISY can send you notifications of any operations.
 
 
After reading the info on this relay you would probably want the NC version and please note this unit has no rated hp rating and if operated while your pump is calling for power would probably destroy the contacts for a one or a few time usage. IOW it is not rated to break the load of a motor load.
 
See Xathros' posts for a much more substantial  industrial relay that can do this over Ethernet from the ISY HA controller.

@LarryILax - any hints as to which Xathros post to find. I did several searches in the UDI forum and didn't find anything that you were referring to for industrial relays.

When the power goes out here, I have water for a long time after.
I can fill the bathtub plus more.
The pressure tank stores a lot of water.

http://www.digital-loggers.com/downloads/Product%20Manuals/Power%20Control/DIN3%20Spec%20Sheet.pdf

On second look the contacts are only rated at 1/2 hp but in series they should be capable of breaking more inductance. In parallel more starting and running current. The thing has some smarts of it's own but no feedback to an ISY HA control that Xathros has reported yet.

I'm using about a dozen Honeywell 5816 sensors through my Elk to control a GreenField Direct ASV100 valve. When I test the setup, I get about 1/2 gallon of water from a faucet after the valve closes. I'd probably get 20+ gallons if I went the relay on the pump route. If you have occasional small leaks in the copper pipe leading to the pressure tank, I'd deal with that directly. I've never really liked copper in plumbing, it's too problematic.

Thanks for everyone's replies.  Decided to take advantage of Smarthome's 20% off Memorial Day sale, and purchase the ELK relay (ELK-9200) along with an Insteon 2450 Low Voltage / Contact closure to control the power on the well pump.  I'll also purchase the Greenfield water shutoff valve (20% off from Home Controls) for the water shutoff on my main line after the water pressure take.  Between the two, I should be covered.  I've read through some prior forum posts on Cocoontech and the UDI forum, so I think I know how to connect everything together.  May need some more advice once everything is delivered and I'm ready to install.

Or you could get the 1" valve here:
 
http://www.surveillent.com/greenfield-direct-asv100-1-controlled-water-valve-wit.aspx
 
and reduce it down to 3/4". You'd save $100+ that way.

Just came across the topic from a search as I am installing water well pump cut off protection in event of a plumbing leak in the house.    
 
Comment #4 mentions putting a cutoff valve after the tank and then cautions the tank can leak. Indeed it can, and perhaps after dishwasher leaks the tank might be the next most likely leak location from corrosion.  i had just had one in my 28-year old water tank (a few weeks after I had removed my home made pump cutout design to upgrade it, installed for 10 years!)  The leak was a corrosion pin hole which sprayed water all over a nearby electrical panel and pump controls (will be fixing that up with plexiglass screening).
 
Caught the leak by chance after only a hour of so and no basement damage, but could have been a lot if had been out for a day.  I always shut pump off for day or more absences.  The best solution for leaks (for a domestic well system has to be cutting off the pump power, much easier than installing a valve.   I also have a pump timer cutout, so that in event of big leak in case the pump can just keep up with the leak without losing pressure the pump will timeout and stop.  The timer does not help if there is a pinhole leak, perhaps more likely than a major leak.  A pin hole tank leak and pump cutoff will still leak the tank and piping system inventory until the pressure drops, my tank is only 40 L so that is not so much, and could be contained with a bit of thought.

Most modern well pressure tanks have a bladder in them. The water is contained in the bladder and never touches the metal pressure tank unless the bladder fails. Bladder failure will become apparent as the tank will soon become waterlogged. Pin hole leaks just don't happen. Then there are the fiberglass tanks.

Mine was a diaphragm tank. The pin hole leak certainly did happen, from corrosion, squirting water up to 5 m away all over the place.  Prior to this the tank pressure cycling was working well. 

A diaphragm is different than a bladder. With a bladder type pressure tank the water is completely contained within the bladder and never touches the metal tank. A diaphragm tank is simply divided by the diaphragm into two separate chambers, one for air and one for water. They can develop leaks without a failure of the diaphragm, as you have noted. Then there are the fiberglass ones. No metal = no corrosion, although they too can experience bladder failures.