Discharge Pipe Into Cistern

[Dungmin]

I have a well pump at 385 feet, the output of which is marginal at best; two loads of laundry within a period of a couple of hours is out of the question. An adjacent neighbor had a new well dug to a depth of 1000 feet and estimates for the same are running in the $25K range. We bought this house two years ago and have thus far managed, but the previous owners had installed a concrete cistern with a capacity of about 6000 gallons with its own pump for obvious reasons.
I am looking to re-route the supply pipe from the well to discharge into the cistern with the pump to be controlled by a float switch, which if I understand correctly is a practical solution. My biggest question at present is can the discharge pipe be installed above the float switch level? My reason for considering this is for concerns for proper sealing of the newly drilled hole and not having to draw down the current water level. The cistern is buried and within a couple of feet of a basement wall which I will also have to go through. There may be good reasons for the discharge pipe to be below the water level, one already in mind is that it would be below the frost line and thereby not require heating.
Here's hoping my question and verbiage make sense- a plumber I ain't. Thanks in advance.

DM,
Afton, Virginny

[speedbump]

Hi DM,

You should discharge the water under the water below the float. This way you aren't rocking the float.

You should also consider some type of timer system along with a Cycle Sensor or Pumptec to protect the motor. You will have to run the pump until it has almost exhausted the well then have the timer shut it off for a long enough time to let the well recover before turning the pump on again. Once you get the tank full, it should be pretty automatic after that.

bob...

[Spaceman Spiff]

I have a 1500 gallon tank with the inlet above the float and have no problems. The open end also acts an an air break, so if the tank gets contaminated it won't get sucked back into the well if the foot valve is leaking. I would think a 6000 gal tank would slosh less than a 1500 gal tank. Maybe you could pump into the side of a tee with a larger bottom leg and open top leg to eliminate splashing, similar to the inlet on a septic tank...

[Bob NH]

If you operate the pump with a float switch such as used for a sump pump BUT WITH CLOSE ON LOW ACTION (what you want is often called a "normally closed" switch because it is closed when hanging with no water), it can be installed with a few inches of range between CLOSE and OPEN. That takes care of the sloshing problem.

You need to protect the well pump as described in one or more of the posts above.

You also need to protect the pump operating from the cistern to your pressure tank. That requires another float switch in the tank. This one will be of the kind that is normally used with a sump pump; sometimes called a "normally open" switch because it is open when it is hanging with no water. It will prevent your pressure pump from operating when the water is low in the cistern.

[Dungmin]

Gentlemen,

Thanks for your insight. I will take all of this into account as I go into this project. I do have a Pumptec for protection on the well pump, but hadn't given any thought to protecting the cistern pump.
I appreciate your help and this forum!

DM
Afton, Virginny

[theelviscerator]

When I was at the water company we put floats inside pvc pipe casing inside tanks to minimize sloshing effect.

[Dungmin]

Me (post originator) again, and my ignorance is still showing. I ordered a liquid level float switch from McMaster-Carr (p/n 51445K91), along with a high amp, 24v control voltage relay. My line of thinking was that I could get a normally closed loop out of the float switch which I could run 24 volts through to operate the relay. Since that no longer appears to be feasible I was pondering plugging a 24v transformer into the piggyback outlet with the output of the transformer going to the relay coil.
My reason for trying to use low control voltage is the run from the cistern to the Pumptec is a distance of about 100 feet, and I'm trying to avoid the extra work and expense involved in running Romex from one end of the house to the other.
Are there good reasons not to be powering a transformer up and down in such a fashion? Again, TIA!

[Rancher]

I'm confused, don't know about anyone else.

1. You should always discharge water from the well above the water in the cistern, you don't want cistern water back in the well.

2. The float valve can operate the 24V relay back at where ever the pump and relay is using small gauge wire (even bell wire), not sure what the question is here. The 24 volt relay pulls almost no current.

Rancher

[speedbump]

1. You should always discharge water from the well above the water in the cistern, you don't want cistern water back in the well.

I didn't think of that when I said under the water, but I guess he could use a vacuum breaker.

The illistration will show how we hook up a float. It's very simple. This is to turn on/off a solonoid valve in an aerator, but the same circuit can be used replacing the solonoid with a contactor.

bob...

[Dungmin]

Welp, if I were to retract and rephrase my question, it would be: "Is power-cycling a plug-in transformer considered taboo?"
Speedbump, I had seen your illustration elsewhere but couldn't make it out clearly. I believe you have provided me with my solution. Thanks(!) from a Tampa native.

DM
Afton, Virginny