Storage Tank Float Switch Control System

[Guy2014]

Thanks to all who helped me understand what I needed for my new creek source water system. Now, I am trying to figure out how to control the pump based on the water level in my storage tank. I'm sure this has been covered before somewhere in this forum, but I can't seem to use the right search criteria to get to it. The storage tank is 700 feet from the pump and 150 feet from the house. So, I think I need a low voltage float switch in the tank connected to some sort of control box at the house which intern energizes the pump via the 550 foot cable run to the pump. I need help with the components - the float switch, low voltage power source, and the switch that energizes the pump.

Am I on the right track? Other ways to accomplish the task? Sources for these components?

 

[Valveman]

Yeah you need a “pump up” float switch and a relay. Here is a drawing of how to wire it.

If you have power at the pump, (no wires run to the house) then you can also use a pressure tank/pressure switch at the pump to shut it off. Then the float switch in the tank only controls a solenoid valve at the storage tank and there is no need for wires to run all the way to the pump. When the storage tank is full the float switch closes the solenoid valve. Hundreds of feet away the little pressure tank is filled and the pressure switch shuts off the pump. When the storage tank is low, the float switch opens the solenoid valve draining the pressure tank and allowing the pressure switch to start the pump.

 

[Sponsor]

 

[Guy2014]

Yeah you need a “pump up” float switch and a relay. Here is a drawing of how to wire it.

If you have power at the pump, (no wires run to the house) then you can also use a pressure tank/pressure switch at the pump to shut it off. Then the float switch in the tank only controls a solenoid valve at the storage tank and there is no need for wires to run all the way to the pump. When the storage tank is full the float switch closes the solenoid valve. Hundreds of feet away the little pressure tank is filled and the pressure switch shuts off the pump. When the storage tank is low, the float switch opens the solenoid valve draining the pressure tank and allowing the pressure switch to start the pump.

Thanks for the circuit diagram and tips. There is no power at the pump, so I go with your first idea. The relay you picture in the diagram, is it an off the shelf item sold at plumbing supply stores? If not, I'll need more detail about the relay. Would this relay work?

http://www.grainger.com/product/MAGNECRAFT-Enclosed-Power-Relay-6CWY5

Or this

http://www.grainger.com/product/OMR...m/rp/s/is/image/Grainger/2XC19_AS01?$smthumb$

I notice both of these relays have coils with very low VA ratings of 4 and 1.8.

The diagram doesn't show the 24 DC volt power supply for the float. If I am not mistaking, the diagram indicates line voltage going through the float switch, correct? In my case, it makes more sense to use low voltage as the cable runs are long and expensive. Can you clarify this point for me?

What current capacity should the 24VDC power supply have. I see inexpensive plug in ones with about 350 mA. Is that sufficient or need more?

The cycle sensor is off the shelf I believe - I've seen it in previous threads.

Thanks...

 

[FoxRedLab]

Terry, based on an answer you gave me in another thread, I think I see why you include a Cycle Sensor on the well-pump side of the above diagram (ripples triggering float switch), but I'm puzzled about the Cycle Sensor on the tank pump. Doesn't the CSV prevent short-cycling? Or is it for protection against dry-pumping in the event the tank runs dry?

 

[Valveman]

The wiring would be a little different with low voltage control, but either one of those relay should work.

The problem with the 700’ run is the impedance between the wires at such a distance will make it act like the relay didn’t open and the pump won’t shut off. I have better luck using DC power on long runs.

Or you can use the float switch to open/close a solenoid valve at the storage tank, and have a regular CSV/pressure switch/small pressure tank at the well to turn the pump on and off without having to run wires for 700’.

And yes the Cycle Sensor on both pumps protects them from any kind of cycling, but in this case it is more to protect in case the well or the storage tank is pumped dry.

 

[Tom Sawyer]

Due to the length of the run and the impedance problem, I would go high voltage with a contractor instead.

 

[LLigetfa]

Or you can use the float switch to open/close a solenoid valve at the storage tank, and have a regular CSV/pressure switch/small pressure tank at the well to turn the pump on and off without having to run wires for 700’.

I agree.

 

[Valveman]

Due to the length of the run and the impedance problem, I would go high voltage with a contractor instead.

I was running 480 volt about 1,000 feet and you couldn't even tell when the switch opened up. I have several that have been working fine for years after I switched them out to DC voltage.

 

[Seanthompson]

J

 

[Reach4]

Guy2014 said "There is no power at the pump".

 

[Guy2014]

The wiring would be a little different with low voltage control, but either one of those relay should work.

The problem with the 700’ run is the impedance between the wires at such a distance will make it act like the relay didn’t open and the pump won’t shut off. I have better luck using DC power on long runs.

Or you can use the float switch to open/close a solenoid valve at the storage tank, and have a regular CSV/pressure switch/small pressure tank at the well to turn the pump on and off without having to run wires for 700’.

And yes the Cycle Sensor on both pumps protects them from any kind of cycling, but in this case it is more to protect in case the well or the storage tank is pumped dry.

It is true the total length of the run is 7oo ft, but, since the house is situated 150 feet from the tank and 550 from the well, I think I can put the relay for the 24VDC float switch circuit at the house. I might have better luck with that much shorter DC circuit.

One last question, Your diagrams both show filling the tank from the top, and taking water for the house from the bottom. I can save 150 ft of pipe if it is OK to fill and remove water from the bottom of the tank using the same pipe. The pipe route from the pump goes very near the house on it's way to the tank. I intend to use gravity feed to the house. I broached this subject in a previous post and it seemed like it should work OK, but, in every illustration I see, the tank is plumed at the top and bottom. Is there some issue with bottom tank plumbing only that I should know?

 

[Valveman]

You can feed the storage tank from the bottom if you want. You can actually tee into the same line that the booster pump is drawing from.

 

[FoxRedLab]

At the risk of sounding really dumb, what's the purpose of the 5-gal bucket inside the storage tank?

 

[DonL]

Support for the Float switch ?

 

[Reach4]

At the risk of sounding really dumb, what's the purpose of the 5-gal bucket inside the storage tank?

IIRC, that is a flat-bottom form for the concrete that the pipe is set into.

 

[Alternety]

Note that if you feed the tank from the bottom, you need to make sure backflow to the well pump is prevented. I have seen discussions here about where and how many backflow preventers, but if I were doing that I would put a readily accessible and maintainable one between the tank and the feed pipe from the well. Don't forget freeze protection if applicable.

 

[Cabin Guy]

valveman, I'm not sure if you are still watching this old thread - but want to ask about the atmospheric storage tank arrangement in the drawings above. 1) does this have to be a submersible pump - or could you put a shallow well pump or booster pump at the outlet of the tank? 2) if a submersible pump, do you need any specific type? 3) if there is a rigid pipe going down into the tank to the submersible, is that enough to deal with rotational force - or is there something else needed for that?

 

[Valveman]

valveman, I'm not sure if you are still watching this old thread - but want to ask about the atmospheric storage tank arrangement in the drawings above. 1) does this have to be a submersible pump - or could you put a shallow well pump or booster pump at the outlet of the tank? 2) if a submersible pump, do you need any specific type? 3) if there is a rigid pipe going down into the tank to the submersible, is that enough to deal with rotational force - or is there something else needed for that?

In that drawing the submersible is in the well and filling the storage tank. There is a shallow well jet pump drawing water out of the storage and supplying water to the house. Here is a different drawing of a jet pump booster, and also one using a sub in the storage just for your comparison.

 

[Cabin Guy]

In that drawing the submersible is in the well and filling the storage tank. There is a shallow well jet pump drawing water out of the storage and supplying water to the house. Here is a different drawing of a jet pump booster, and also one using a sub in the storage just for your comparison.

View attachment 54566

View attachment 54567

Thank you. Makes sense. I am essentially trying to mimic the setup in the "Well Manager" (https://www.wellmanager.com/) - without having it cost me $7K. The one additional component would be putting a timer in to activate the pump periodically to build up the water level without pumping our low yield well dry. In that situation, I assume the timer would just go upstream of the cycle sensor in the above wiring diagram. Make sense?

 

[Valveman]

The Cycle Sensor has a timer built in. It only lets the pump run dry for 10 seconds, and then you set the timer for however long you want the well to recover.