Electrical Question

Is there a device out there that would shut off a circuit completely if the circuit drew power for a constant hour (or some determined amount of time). I'm looking for something that would shut off the power circuit to a well pump in the event it was running constantly for say an hour (meaning either a toilet was running or a faucet was left on by accident). This would prevent the pump from running for an extended period of time, risking running the well dry.

The tricky part is, if the pump on ran for 15 minutes, then the system would need to reset itself. I know there are devices that only allow something to be powered for X amount of time, but at the end of the amount of time, if triggered again, it'll start the clock again. I want something that, in the event there is a power draw for a solid hour, it completely kicks off the circuit and it'd have to be manually reset. You can all probably guess what happened recently to provoke this kind of question...

Thoughts, ideas or suggestions?

 

maybe this would work - remote relay controlled outlet by furman:
http://www.furmansound.com/product.php?div=01&id=MP-15

 

This usually requires some circuitry, called a Watch dog timer. Then you would need a rotometer, this will go inline with the water system, telling the WDT that the water is running, then you would have to tell a Solid State relay to then switch the power off.

 

That could work but I'd still need a control unit to run it. This seems to be a high voltage outlet that can be controlled by a low voltage system and doesn't come with any of the low voltage circuitry necessary to program it.

 

Interesting... so the rotometer starts the Watchdog, then if the rotometer stops, it resets the Watchdog. If not, the Watchdog would assume a malfunction and cut the power. How hard are these things to install? I'm looking at their website now and some of it seems like it could be way over a typical homeowner's head

 

Examples of what it would take. May be able to get around the WDT, but i would have to think about that.

http://datasheets.maxim-ic.com/en/ds/MAX6814.pdf
http://www.gemssensors.com/Products/Flow
https://www.google.com/search?q=sol....,cf.osb&fp=f9b3de66ba842386&biw=1630&bih=821

 

Exactly!
Yeah, it would be a little complicated, for the typical home owner, but let me think about this for a few, there may be a simpler solution.
S

 

This situation is rather unique, in the fact that you want to monitor a closed loop system per say. It can be done, but it will take some circuitry.

 

I think that's about all I need to know. If it's something really involved, I won't even mess with it. I was hoping there was an 'off the shelf' product that I could install but it seems that's not the case. This happened on my parent's house while they were away for the weekend and I was going to install this as a preventative measure. They had a toilet run all weekend and ran the well dry. I'll just tell them to turn that circuit off on the panel when they leave and maybe run a warning light to their kitchen that lights up when there is a draw on that circuit. That way they'd know there's a draw and can find out what's leaking.

 

Should be easy (for me ) to do with a $2 micro-controller and a few pieces of circuitry.
Sounds like you have the logic figured out, would then just convert it to software.

You could communicate with the controller via Hyper Terminal to tweak the times etc...

 

I haven't messed with it in a couple weeks The truck broke, then the motorcycle, then the house renovations called... I'll get looking into this again shortly and post up the final results.

 

How about a pump like this?
http://www.grainger.com/Grainger/ZOELLER-Sump-Pump-4HEY2?Pid=search

there are a few different models,

 

I don't need a pump though, I need a something to cut off the circuit in the event the well pump runs amuck.

 

Franklin Electric makes a controller for their 4” subs that has a sensor for running dry. This unit is called the sub troll, I think it protects against other issues too.. clogged screens ect.

 

Interesting... Thanks, I'll give that a look! I might be able to rig something like that to work!

 

I believe this is what 03coma is referring to \/\/\/
http://www.franklin-electric.com/residential-light-commercial/protection/protection/pumptec.aspx

 

What about a flow switch. I use one for a booster pump in my home. When the water is turned on, the switch flips and turns on the booster pump. No voltage till the flow switch is tripped.

Slap this baby on a timer for an hour. When the timer trips, it kills power to your pump until you go out and manually reset it. You could even direct short it if you want to kick the breaker.

 

Thanks for the link! I need to research this a bit more.

That's generally the idea the problem is it needs to be able to reset itself. I only want it to cut power if the flow is going for an hour straight. Otherwise, if the flow is on for 30 minutes, I want it to reset and not just shut off like a timer would.

The other issue with just using a timer is this:
Flow turns on due to a leaking toilet, flow switch trips timer, timer turns pump off in an hour, 5 seconds later, toilet is still leaking, flow switch trips the timer for another hour. It'd be perpetual.

The manual reset thing would work but it'd just be a PITA. Can you imagine having to remember to reset the well pump every time you use any faucet in the house? I think I'd go nuts but that's also what's driving me to look into something that can be programmed.

I appreciate the ideas!! Keep them coming, I'll probably use a mix-match of the ideas to make something work.

 

It would reset. Everytime the flow switch wasnt used a new hour would start.

The only time you would have to reset it is if it ran for an hour straight for some reason. If it ran for 45 mins for a long shower, as soon as the shower turned off, the flow switch would stop and the timer would reset to 1 hour.

When i was in electronics school we built a timer that reset everytime power was lost. I'll have to remember what it was called. They probably sell them at Radio Shack for 5 bucks.

 

Hmmm... that's exactly what I'm looking for. I'll get looking at this and let you know how it works out! Thanks Kris