I described in minute detail how a pump would be controlled, back at post #4. Every single connection. The lower level detector energises the motor control relay, which stays latched until the upper level detector opens and releases the relay. With the LED device it would need a normally closed relay to operate and release the latched pump control relay. I have used that scheme in various machines perhaps a hundred times over the years.

Yes and in post #12 I described another scenario. If what the OP has in mind is what I described there is more to it. Potable water is not always available so the end user needs to know when water is available. When water is available it is not like the luxuries we enjoy. It is simply there with maybe a few PSI and that is as good as it gets. The pump draws off a non pressurized supply and often the guy with the better pump gets the lions share of the water. Run a pump less a supply and you burn up the pump. In some countries the electricity also comes and goes so go figure.

Anyway while we can all come up with great schemes and how to less knowing exactly what the thread starter is looking to do we really have nothing. Heck, we don't even know if it's potable water or where the tank is with respect to the supply. I have seen the scenario I used in a good many countries I lived in and traveled in. Unless the thread starter returns and answers some questions we got nothing?

Ron

 

I described in minute detail how a pump would be controlled, back at post #4

Squze me.

When I read your post I was not able to follow what you were describing. A ton of verbiage which I failed to make sense of. Best I got out of #4 was that two relays are used. When the first is energized (low level) the pump comes on. The second relay cuts power. Fairly easy explanation, but with all the what-for's and there-in's, I got lost and just moved on to the next post.

Look how this one post (post #1) has activated a lot of attention. The TS has not returned with any more information. Not even a "thanks y'all".

In some countries the electricity also comes and goes

Maybe this is why we haven't heard back. But until I'm convinced the TS is actively seeking a solution, willing to provide more detail and become interactive in this discussion - I'm out-a-here!

 

@Tonyr1084 It's the Internet and anonymity. People will ask the same question at several different sites and just for good measure they will ask a few real people down the road. Then they will go with whoever gives the quickest answer and forget about the rest. If you are expecting online people to say "please and thank you" (it does happen sometimes) then you have not been online long enough.

 

If you are expecting online people to say "please and thank you" ••• then you have not been online long enough.

What's wrong with civility? I give it and expect it. When those "anonymous" people want to be less than civil - that's their loss. While I know it's true that you can catch more flies with honey than you can with vinegar, you should see how many I can catch with shit. And if giving someone a little shit now and then makes them a better person - then they are like flowers that grow when fertilizer is applied.

 

Just for fun I went ahead and drew out @MisterBill2's circuit as I interpret it. It may not be exactly what he's specifying - but it's just my shot at understanding how he's approaching the problem.

When the tank is full, S1 closes and energizes K1. When the water level falls, K1 falls out, applying Low V to the NO node of K2. Nothing happens. When the water level falls to the low limit then S2 closes and energizes K2. When K2 is energized it holds itself on via nodes NO and C even after the water level has begun to rise. Water rises until S1 again closes and energizes K1, which de-energizes K2 and the pump shuts off. K1 is SPDT K2 is DPDT. The switches are Momentary Closed. The low limit switch closes only momentarily, when the water level is low enough. S1 momentarily closes when the tank is full. It remains closed until some water is used, which means K1 is on until the water level falls off from 100% full. Whatever point that may be.

 

Just for fun I went ahead and drew out @MisterBill2's circuit as I interpret it. It may not be exactly what he's specifying - but it's just my shot at understanding how he's approaching the problem.
View attachment 247590
When the tank is full, S1 closes and energizes K1. When the water level falls, K1 falls out, applying Low V to the NO node of K2. Nothing happens. When the water level falls to the low limit then S2 closes and energizes K2. When K2 is energized it holds itself on via nodes NO and C even after the water level has begun to rise. Water rises until S1 again closes and energizes K1, which de-energizes K2 and the pump shuts off. K1 is SPDT K2 is DPDT. The switches are Momentary Closed. The low limit switch closes only momentarily, when the water level is low enough. S1 momentarily closes when the tank is full. It remains closed until some water is used, which means K1 is on until the water level falls off from 100% full. Whatever point that may be.

YES!, This is the circuit that I was describing, but with symbols that are different than I use. But the same circuit and identical function. Thanks, Tony.