Well&pump questions

[CobyRupert]

Yes, switching one leg is done. But note, although no current can flow, you will still have voltage in the line, through the stopped motor windings and at both side of the open switch.

You can’t do this easily with just one switch or the motor will be rapidly switching on and off any time the water level dips. (Unless the switch changes status at very different water height levels, i.e. has a large hysteresis)
You will most likely want a (normally closed) level switch-low (LSL) that opens when it floats and closes when water dips below it.
This LSL switch should be wired in series through another level switch-high (LSH) to energize a relay.
One of the relay contacts is wired to open/close (start/stop) power to the pump.
Another one of the relay’s contacts is wired around (parallel with) the LSL so that the relay stays energized and keeps power going to the pump even when the LSL immediately starts floating and it’s contacts open while the cistern is filling.
Only when the higher LSH is satisfied does its contacts open to drop out the relay and stop the pump.
The system is now at standby again, waiting for the LSL to re-initiate the sequence when the water is low.

Additional secondary LSL and LSH switches, set lower and higher respectively, are often used to trigger alarms (a horn or light, etc..) signaling that the tank is either going to run dry or overflow if the primary controls fail.

Then again, you probably don’t want a LSL switch to automatically turn on the pump if you don’t have enough well water to fill the cistern. If so, put a Manual-Off-Auto selector switch (electrically) ahead of all switches that either routes the circuit through the above mentioned switches (Auto), while the Manual position bypasses the LSL switch, thus pump still shuts off at high level. Bypass LSH too if you want the capability to overflow the cistern in Manual.

….but you mention a pressure switch? Does that mean an existing ballast tank? Do you plan to integrate a cistern with a ballast tank and pressure switch? Will the cistern’s elevation itself provide water pressure?

 

[rScotty]

Okay, mostly not really tractor oriented other than I'll be using the tractor in some capacity I'm sure... but regardless I'm hoping to pick some brains!

Situation - my house is fed by a shallow well, water quality is excellent. Any drilled well the quality isn't good, typically high Sulphur and iron content. Downside of my shallow well is during prolonged droughts the water level in the well drops down to the point that I can easily draw it down to the point the pump sucks air. Worst case scenarios the water level in the well drops below the pump pickup. Pump is a submersible style.

My situation isn't any different then my neighbors. They either suffer with poor water quality or good quality but limited.

My one neighbor did what I've been thinking of doing which is installed a cistern that is filled by a good well which keeps the cistern topped up at its own rate. During droughts the cistern is large enough to service the house until the water in the well comes back up.

So I'm thinking I'll do the same. Now finally the question!

The submersible pump is 220v, can I put a float switch on one legs of the pump, will that turn it off or will it damage the pump?
Second question is does anyone have any experience with something that can monitor the water level in a cistern or tank? I will want to know when the cistern isn't getting filled.

Thanks, E.

Yes, you can put in a simple float switch. It will have to be a 220 type that switches both legs rather than one. And pay attention to special waterproof connectors typically used in well pump installations.

Increasing the reserve capacity surrounding the shallow well is another way to solve the problem.

We use a shallow well and treat the water for our house. The inflow is not strong, but the level stays pretty constant because of a lot of reserve.The basic well uses 5 foot diameter well rings surrounded by several feet of sand and gravel inside of a geotextile barrier cloth. So In spite of not being deep, the well has a large reservoir to draw from.
It was dug with our backhoe and everything put in place with the FEL. A weekend project - inspected and approved by the state, too.

 

[steve tym]

Switching one leg is not great, but it shouldn't hurt the motor. At least not Franklin motors, can't speak for some of the new motors on the market.

 

[Valveman]

Sorry I missed this. Yes, you can use a float and just cut one of the wires if the float switch is rated for the max amps of the motor. If not, you will need a contactor or relay to energize the pump, while the float switch just energizes the relay. Like this.

You also need something like the Cycle Sensor shown in the drawings, which can be used to protect the well pump when the well runs dry as well as protect the booster pump if the cistern goes dry.

Cycle Sensor Pump Monitor – Cycle Stop Valves, Inc

 

[FletcherDarius]

Yes, you can use a float switch on one leg of the 220v submersible pump to control its operation. A float switch can act as a simple on/off switch based on the water level in the bitcoin education cistern. When the water level rises to a certain point, the float switch will activate and turn on the pump to fill the cistern. Conversely, when the water level drops below a certain threshold, the float switch will deactivate and turn off the pump. This setup is a common way to automate the pump's operation and prevent it from running dry.

 

[Everhard]

I recently spoke to an electrician and he said putting a float on one leg of the 220v going to the pump will work and won't in any way hurt the pump. Which was my big concern of course otherwise I'd have to look at some other way to turn off the pump. The float is a simple easy way to do it.
Note I'm specifically talking about my well pump because it's located a long way away from the house so not easily monitored. The cistern when I set that up would be near the house and yes when I install that I would set it up to be monitored. I want to know when the well is no longer supplying the cistern which I'll know based on the cistern not filling back to full.

E.

 

[rScotty]

SNIP

The cistern when I set that up would be near the house and yes when I install that I would set it up to be monitored. I want to know when the well is no longer supplying the cistern which I'll know based on the cistern not filling back to full.

E.

There are so many opinions on things today that it is a pleasure to be able to post something helpful that nobody can argue against:
Be sure to use either a back flow preventer or an air gap in the pipe that fills the cistern.
rScotty

 

[JasperFrank]

What kind of cistern are you thinking? All my neighbors use large poly tanks above ground, pumped up to, and then use gravity for water pressure. I use a 1,500 gal underground concrete tank, passively feed by the roof gutters on the garage with an overflow outlet to a french drain area. I get water from it via a jet pump, which was supposed to self prime, but doesn't. The system is entirely isolated from the domestic household water, which comes from the deep well, that only supplies about 8 gallons a minute, and barely passed inspection. The cistern only supplies Ag water for the lawn, gardens and for possible fire control. 1,500 gallons, we have found it to be way too small for the long Oregon Summers. Better than not having it, but wish we had gone larger capacity to carry us over, with out having to refill the cistern from the well at least once a summer. This can take all day. We really needed 5,000 gallons of storage cause that's all free water in Oregon during Winter and Spring.

 

[GSVette]

What kind of cistern are you thinking? All my neighbors use large poly tanks above ground, pumped up to, and then use gravity for water pressure. I use a 1,500 gal underground concrete tank, passively feed by the roof gutters on the garage with an overflow outlet to a french drain area. I get water from it via a jet pump, which was supposed to self prime, but doesn't. The system is entirely isolated from the domestic household water, which comes from the deep well, that only supplies about 8 gallons a minute, and barely passed inspection. The cistern only supplies Ag water for the lawn, gardens and for possible fire control. 1,500 gallons, we have found it to be way too small for the long Oregon Summers. Better than not having it, but wish we had gone larger capacity to carry us over, with out having to refill the cistern from the well at least once a summer. This can take all day. We really needed 5,000 gallons of storage cause that's all free water in Oregon during Winter and Spring.

Wow 8 gpm and it barely passed? Iirc around here it less than 1.5gpm that is deemed inadequate for domestic use and then requires the installation of a cistern if sufficient capacity.

I lucked out in our little, large parcel development-my well came in at 10gpm ( at 220’)- most of my neighbors were less than 4 at more than 400’ and all installed cisterns. I likely will just for reserve capacity (never pumped my well down but you never know what the future holds).

 

[ericm979]

I recently spoke to an electrician and he said putting a float on one leg of the 220v going to the pump will work and won't in any way hurt the pump.

Our water system has a 10k gallon tank gravity feeding the house, with a float switch to turn the well pump on and off. The float switch circuit switches a contactor at the pump so the 8a to the pump does not have to go hundreds of feet to the tank and through the switch.

One tip I got from the last well service guy is to make the float switch on and off points far apart. That way the pump has to start fewer times and that helps it live longer.