Well pump, float switch, booster pump help please

[Chetwynd]

I need help figuring out how to configure and install my well pump/tank/booster setup.

Yes, I know I can pay someone a bunch of money to do it for me, but that's not in my nature. I figure out, eventually, how to do everything. I have more time than money. I'm not opposed to paying someone to help me or tell me how to do it.

This is a bit of a story...

House well went dry, so the current configuration is to turn on an ag pump which has a valve to fill a 1000 gallon storage tank. Out of the bottom of the storage tank the water gets pressurized using a Grundfos booster pump, which pushes it into the existing pressure tank, and on to the house. I'm not sure that there's currently any point to the pressure tank.

Original (prior to well going dry issue) configuration was 240v to the pressure tank switch, then on to the Flint & Walling control box, to the well pump. Water came out directly to the pressure tank, and on to the house.

I deepened the well, and need to ditch the ag well setup and go back to using the house well. None of this was setup by me originally, I bought the property with this all in place, recently.

Ideal setup is as follows:

1. house well pump fills storage tank.
2. when water level drops X amount, float switch tells the pump to turn on and refill it.
3. pressure tank appears to have a normal Square D 30/50 pressure switch on it, which is wired to a Flint & Walling control box as shown in the photo. A drop in pressure in the pressure tank should trigger the Grundfos booster pump to re-pressurize it.

One issue is that the booster pump is plugged directly into 120v, and is NOT triggered by a drop in pressure in the pressure tank. Power is currently OFF to the pressure tank switch.

Since my casing is only 4" now, I'm going to use a Grundfos 3" pump that I got a great deal on before I knew I was going to have a use for it. Grundfos 11 SQF 2, which runs on 30-300 VDC, or 90-240 VAC. I may end up getting a lower-cost 3-wire pump and save the Grundfos beast for future use, in which case maybe I can use the existing controller.

So, I guess what I need help with is what kind of float switch, how to wire it, whether I need a pump controller and if so is the existing one OK? I'm guessing no because the old pump is a 3 wire and the new Grundfos is 2 plus ground. Then, how do I connect the pressure tank switch to the booster pump when the booster pump has a standard 3-prong plug end on it?

I know this is a lot. You're a badass if you can help.

Thank you!

 

[Valveman]

Depends on which Grundfos booster you have if it is any good or not. But the Scala doesn't need a pressure tank, and is one of the reasons it is not a reliable pump. If you are not going solar, the standard Grundfos SQ pump with a PK1A is the best you could do for a 3" pump and constant pressure control. The SQF2 is made for solar and won't work with a Cycle Stop Valve.

 

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[Chetwynd]

I see no point in using a CSV with a storage tank, so I won't be going in that direction. Thank you though.

 

[Reach4]

Float switch to control the well pump is "pump up" or NC (normally closed).

You could use a lower float switch to inhibit the pressure pump if the tank runs dry. That would be type "pump down" or NO (normally open).

 

[Valveman]

I see no point in using a CSV with a storage tank, so I won't be going in that direction. Thank you though.

Having a storage tank does not negate the need for a Cycle Stop Valve. However, having the Scala type pump does negate the need for a Cycle Stop Valve as the variable speed of the Scala acts like a CSV. Both the Scala and the CSV are designed to deliver constant pressure to the house. The difference is the Scala is a technically complicated and expensive variable speed drive that is designed to be replaced often, while the CSV is a simple, inexpensive valve that will last and make your pump last many decades without any maintenance or problems.

 

[Reach4]

The CSV would not be for a well pump, which fills the atmospheric tank. The SQF 2 pump was proposed as the well pump.

 

[Chetwynd]

The CSV would not be for a well pump, which fills the atmospheric tank. The SQF 2 pump was proposed as the well pump.

I get it, but that's a $2000 pump, and for pumping once every few days to refill a storage tank I don't think I need a $2000 pump.

 

[Chetwynd]

Having a storage tank does not negate the need for a Cycle Stop Valve. However, having the Scala type pump does negate the need for a Cycle Stop Valve as the variable speed of the Scala acts like a CSV. Both the Scala and the CSV are designed to deliver constant pressure to the house. The difference is the Scala is a technically complicated and expensive variable speed drive that is designed to be replaced often, while the CSV is a simple, inexpensive valve that will last and make your pump last many decades without any maintenance or problems.

I don't follow. The CSV's point is to reduce the cycles on the well pump. By having let's say a 1000 gallon difference between where the float switch triggers the well pump to turn on and off when refilling the storage tank, the only cycling is the booster pump keeping the pressure tanks pressurized and whenever we use 1000 gallons...every few days. Booster pumps being less expensive and far easier to replace than well pumps - no?

 

[Valveman]

Look at the drawing I posted. There is nothing on the well pump except a float switch in the cistern and a Cycle Sensor (dry well protector). Most people don't install a cistern just to limit the cycles on the well pump, but rather because the well is a low producer. If the well makes plenty of water, all you need is a Cycle Stop Valve on the well pump to limit the cycling and make the pump last a long time.

But if you are using a cistern just to limit well pump cycling, and the well produces plenty of water, you don't even need the Cycle Sensor, just the float switch. And no, I don't think you need a 2K priced well pump either. That is why I mentioned the SQ instead of the SQFlex. But you really don't even need to spend that much for an SQ, as any 4" well pump will work fine.

Pumping from a cistern, a Cycle Stop Valve and a 4.5 gallon size pressure tank controlling a standard and long lasting jet pump will deliver the same or better constant pressure as the Scala. The Scala doesn't need a pressure tank and delivers good constant pressure when it is working. The Scala is just not a reliable, long lasting, or inexpensive way to get constant pressure like the CSV is.