Water pump shutoff?

[carolinacoast]

I have just replaced my AC freshwater pump for the 2nd time (Thanks Grainger - this one was free) because the water tank ran dry each time, while I was away from the boat. Once was a guest taking a princess shower, and the second time was my wife doing laundry. Admittedly, my water gauges are inop. If there is water, obviously there is not a problem. Tank Tender is on the list, but have not gotten to it yet.

The pump ran dry, overheated and ruined the seal. My question is: Does anyone have a good solution for getting the pump to stop? The pump is a Dayton 1/2hp 115 volt shallow well jet pump.

My thoughts include a flow switch of some sort, or a smaller breaker if the pump draws more dry than with water on the supply side. The breaker on the panel obviously does not blow, currently. Would appreciate advice. Thanks.

 

[MikeP]

In the oem system that capability is in the switch if it is the correct one for the application. The correct switch has a low pressure shut off that turns off power to the pump when the system water pressure drops below 15PSI, which will occur as the tank runs out of water since the pump can't maintain the pressure without water. The switch is just a standard pump type switch available at any hardware store. Usually there are several different switches in stock. They will probably have a couple that cover different pressure ranges and some that do and some that don't have the low pressure shut-off. One like this - http://www.amazon.com/Square-Schnei...-9&keywords=square+d+pumptrol+pressure+switch

Obviously you have to get the switch with the correct voltage/pressure for your application

 

[carolinacoast]

Fabulous. Thanks MikeP. Mine do not have the low pressure cutoff. Will replace both.

 

[GJH]

Just to confirm what Mike said. These are often referred to as "run dry" switches, very common beyond the boating world.

Second I would highly recommend getting a Watercounter, not a Tank Tender or other gauge. It will tell you exactly how much water has been used and is left in the tank. By checking before and after, you will know how many gallon different cycle choices use on your laundry and f applicable dish washer, and how many gallons different lengths of shower use, etc. Made a huge difference to us when we lived on moorings full time, or even nowadays when we may anchor out for a week. Obviously is handy when you are at the dock too and not using the dock water, but there a solution to low water is immediately at hand. One of the very best enhancements we made to the boat.

http://www.watercounter.com/

 

[Angela]

Thanks for the reminders, George and Mike. I've been meaning to put a low pressure cut off switch on my AC water pump, and get a watercounter since I have no gauges for my water tanks, other than opening the big nut on top and taking a peek, and that's getting real old! I had totally forgotten about the watercounter. I like that concept.

 

[Canuck Dennis]

another option is to install a run timer, 115 v a/c you can set the run time to turnoff the pump if it runs more than say 5 minutes, I use one of those on my 240 V pump , the 32 v shuts down on low pressure setting.

 

[aquacraig@shaw.ca]

The water counter seems like a very good idea! Does it measure fairly accurately or do you still have to worry??? Tank gauges are a big PITA

 

[GJH]

We have been using the Watercounter extensively for 5 1/2 years. We ran it down to 5 gallons and still had water flow, so no, we don't worry about it. The real beauty of it is the ability to accurately measure how much certain activities consume, allowing very precise water usage management. This comes in very handy when you are away from a dock for long periods of time, and/or in an area where there is a charge for fresh water. I had once seriously considered installing a water maker on the boat, but could never cost-justify it. We can live pretty comfortably, the two of us, for three weeks on 350 gallons without feeling much in the way of deprivation. We do "cheat" a bit as my wife prefers bottled water for drinking convenience, though we also use a Brita filter set up. I find the tank water perfectly drinkable, but then she drinks bottled water everywhere on land too.

They also have a system for use with water makers that is pretty slick, no direct experience with that but I have seen one installed on a boat and they seemed very happy with it.

The quality is very high and the couple that makes and sells the product are very nice people.

 

[MikeP]

I agree that the water counter seems to be the best thing around for this purpose. I installed a new tank gauge a few months ago which I'm quite happy with - heck, it's the first time the boat has ever had a WORKING water tank gauge - but if we were to get back to more extended operation like we used to do when we lived on Long Island, I would definitely get a water counter.

At the moment our use is never more than maybe 3 days at a time away from the dock so as long as the tank is filled before we leave (287 gal), it's not an issue.

But we are water hogs... When we were doing week+ trips, five days was about as long as we could go without going to "conservation mode."

 

[carolinacoast]

Update from last year. Thanks guys. the 'run dry' switches are working great. Thank You.