About 20 years ago, a friend of mine came to me saying that he had to repair a customer’s  water level control made out of electromechanical relays which was falling apart.  He understood that the original control relied on conductivity of water. The customer didn’t want any type of float switch so he had to stick to the way it was meant to work.

He could start the pump whenever water fell below the “low” level electrode and pump would stop once it reached the “high” level electrode but, as water was consumed and its level barely dropped just below “high”, his circuit would re-start the pump just to stop it as soon as “high” electrode was touched by water again. This process kept going on and on until he switched power off. His circuit was oscillating which was not good for a 5 HP water pump or any pump at all.

He needed help. At this point I asked him that instead of working with relays, wouldn’t it be nice if the control were electronic which would probably be less expensive, more reliable and have a longer life?

 I intended to build a kit for Club Jameco out of how I remembered this control worked and this is what this instructable is all about. 

*** Disclaimer: This kit is meant to operate with equipment such as line operated water pumps or motor starter relays and/or contactors at lower control voltages. Line voltage is dangerous and if mishandled can cause injury or death. If you are not familiar or have not worked with line operated equipment, have a licensed electrician do the power wiring for you. This kit is meant to be educational in nature and can be used with line operated equipment if National Electric Code guidelines are followed. ***

Step 1: Proposed Control Slide show

The slide show included in this instructable shows the basic operating theory behind this control. It assumes that the pump is a small plug-in pump. This control has a small 12V coil relay whose contacts are rated at 10A 120V. You can select any relay to suit your water pump's power source.

Thanks for such an gr8 circuit but<br>I'm facing some problem with the circuit<br>The low level of the upper water tank is not working<br>i.e, motor just get started as soon as a little amount of water is taken out out of the upper water tank<br>Hope you will help me out soon<br>Thanks ;)
<p>Hey VickyS11,</p><p>That's a nice circuit board you got there! Now, you will have to test the circuit the way it was tested in the last steps of this instructable.</p><p>Get yourself a multimeter in DC Volts, and test the low level electrode input on pin 1 of CD4001, when low level wire is into and out of the water in the cointainer you'll be using for testing. When wire is out of water, voltage should be around 8 to 9 volts, assuming your PS is 12V. When wire is into the water, voltage should be around 0.8V. Remember, Ground wire must be into the same water container all the time, otherwise, you won't get these readings!!!</p><p>If you want Green LED to come on, pump protect and ground wires should be dipped into the same water container. If the voltage readings you got in previous paragraph were about right, dip Low level wire along with Pump Protect and ground wires in same water container. Green LED should stay on as this simulates water level going up. As soon as you dip High level wire into same water container, Green LED will go out which simulates pump being turned off.</p><p>To simulate water level going down due to consumption, pull High level wire out of water container and Green LED should remain off. As soon as you pull Low level wire out of water container, Green LED will come back on again.</p><p>If for any reason, your circuit does not behave this way, make sure to also test CD4001 pin 13 which corresponds to S-R latch input that comes from High level wire through a NOR gate wired as a NOT gate. Remember that High level wire goes first to CD4001 pins 8 and 9 which are the inputs of gate wired as NOT gate, pin 10 is its output which is connected to pin 13 of CD4001. So, if High level wire is into water along with ground wire, pins 8 and 9 should read around 0.8V. CD4001 pin 13 should read around 12V. When High level wire is out of the water, pins 8 and 9 should read about 8V to 9V and pin 13 should read between 0V and 0.8V.</p><p>For proper operation of S-R latch, check truth table on slide show in step 1 and verify its outputs as you test inputs. Also, check for proper continuity in all traces on your circuit board. There may be an open line or solder bridging somewhere. </p><p>Hope this helps.</p><p>rlarios</p>
Thanks rlarios for such a detailed info<br>I will definately try this out<br>Btw u wanted to tell u that i have used 15k ohm resistor instead of 2.2m ohm which is close to the relay( and that adjustment worked)<br><br>And now a new problem came out that the high level probe is not able to switch off the motor<br>Previously it was working<br><br>And in first query the problem was<br>Once the tank gets full after that if the high level probe is taken out the motor get started within a sec<br><br>Btw thanks a lot
<p>VickyS11,</p><p>The 2.2M ohm resistors and the &quot;equivalent&quot; resistance of water form a voltage divider between 12V and ground. Your 15K ohm resistor is less than 1% the value of 2.2M ohm, no wonder the circuit is acting up.</p><p>There are three electrode inputs, therefore, there is one 2.2M ohm pull-up resistors at each input. If voltage does not change the way I described in my previous message as you dip and pull wires into and out of water, then change resistors back to 2.2M ohm and test again.</p><p>Even the circuit with transistors -to turn red LED on and off- was designed taking into account this 2.2M resistor because pump protect electrode wire goes into CD4001 pin 6. The purpose of these resistors is to ensure that logic levels will be properly detected by CD4001.</p><p>Let me know how things turn out.</p>
Thanks for such a detail... I have implemented this at my home...Every thing is working fine... However i want to enhace this circuit to avoid base tank over flow such that if base tank reaches high motor should start untill overhead tank reaches high or base tank reaches pump protection
<p>Hi AnsariT,</p><p>In the circuit schematic, you'll see that when water level in upper tank is below LOW level electrode, pump would start provided water level in &quot;base&quot; tank is above PUMP PROTECT electrode.</p><p>You can add a a &quot;base&quot; tank overflow electrode and run a line through a NOT gate. The output of this NOT gate would become one input of a 2 input OR gate, the other input would be the LOW level electrode. The output of this OR gate would take the place of the LOW level electrode into the S-R latch formed by the two NOR gates.</p><p>Try this (at least on paper) and let me know whether this Works for you.</p><p>rlarios</p>
Thanks.... I was hoping existing ic will do this by some how manipulating the input of ic pin... Any will try your suggestion once i get time and update the thread
<p>AnsariT,</p><p>The base tank overflow electrode is an extra input that needs to be processed. The circuit -as is- in the instructable used all 4 gates in CD4001. You can use an extra CD4001 and manipulate the gates to behave the way I described in my previous message. I can send you a schematic later today.</p>
Hey is urs low level wire of the upper water tank is working<br><br>i.e, as rlarios told in the tutorial that if circuit is on it will check that the water gets down below of the low level wire ( once the tank is full ) and then it turns on the motor<br><br>plz help me out<br>Thanks ;)
<p>Hi there!</p><p>I would be interested in adapting this to be used to top up my pool automatically.</p><p>I already have water supply under pressure, so I was just hoping to have this circuit open a valve to add water until the pool is full again. So the stop limit would be just below the skimmer box top and the add limit would be just before the skimmer box has no water.</p><p>I have some electronics knowledge and can solder and follow instructions well enough, but need guidance to what to do and what I need.</p><p>Cheers,</p><p>Josh</p>
<p>Josh,</p><p>See:</p><p><a href="http://www.instructables.com/id/Automatic-Pool-Water-Filler/" rel="nofollow">http://www.instructables.com/id/Automatic-Pool-Wat...</a></p><p>Maybe you can get some ideas. This Instructable claims that your pool water control costs $15 bucks or so.</p><p>rlarios</p>
Hi there Josh,<br><br>I believe, you would have to check on your local construction and/or electrical codes whether this type of control would be allowed for your application.<br><br>Maybe, non contact sensors such as ultrasonic could work? Or, what about some sort of pressure sensor? It never occurred to me using this type of control for a swimming pool, but I'll check it out and let you know.<br><br>rlarios<br>
cool. it's an awesome circuit. I m planning to make it. I Have got all the parts. but could u plz send the PCB design so I could etch that on a PCB. the file which u attached isn't opening. Plz reply ASAP....
Hi, its a single phase 100 mm submersible pump. With HP rating 1.0 and capacitor rating 30 MFD. Apart from this I Dnt have an specs. Cause its submersed underwater. Kindly help me out with some wiring diagram and component
Can you make a simple drawing showing the tank you intend to fill up and the water reservoir where your pump is or would be? <br><br>rlarios<br>
yes, I am attaching the drawing of my tank and the pump.. the tank is on first floor..and the pump is around 150 feet underground. and I am sending the motor starter diagram as well..
instruct me with some simple circuit if possible..
<p>Can you tell me your supply's rated voltage? </p><p>I can identify the motor's Run (R), Start (Y) and Common (B) terminals. </p><p>However, the starter's box in the schematic seems to show only line side and load side terminals. How is it switched on or off? Is it a contactor? If it is, what's its coil operating voltage? </p><p>The key here is to identify how we can turn motor starter on/off. </p><p>rlarios</p>
this is the complete pic of the controller box.. the main supply powers that box. thank you. hope I gave u the required information. thank you.
<p>I'm seeing that red button-like-box on the front of the starter, do you push it in to start the pump or how do you start the motor? How do you stop the motor when you have to? </p><p>Also, what are those two screws on the left of the starter for? Do you have other two screws on its right? Are they there to keep the starter together or are they the starter's coil terminals? </p><p>Remember, we have to identify how this motor can be energized. If this &quot;starter&quot; is just a push button with no electrical parts, you'll have to get a hold of a power contactor. </p>
yes the red button is just the starter switch to power off the pump, above the red button there is a green one provided to power on the pump.. <br><br>Those screws are just to keep the starter in place.. the terminal for starters are on top side not beside it.. hope I clear ur doubt..thank you.
<p>automated_engineer, </p><p>Use circuit 1 shown on step 2 of this instructable. Just make sure that the contactor's coil you select is rated for 230V. This contactor would replace your &quot;starter&quot;. I'm assuming, of course, that your 230V come from line and neutral wires. If your 230V come from 2 phases (as it is in America), use circuit 2.</p><p>rlarios</p>
hi, thanks for your feedback.. can you plz give me the list of all the component required to do so.. and a rough sketch of how to connect those component.. as you said the contractor will replace My starter.. do I need to change the starter only and keep the remaining part as it is.. or do I have to built another box.. and this box is not needed..thank you.
<p>automated_engineer,</p><p>I would just remove the starter from that box and replace it with a contactor whose coil is rated at 230V. The contacts should have same rating as old starter's contacts. </p><p>I would use the same parts in this instructable except the transformer feeding the controller and the small relay RLY1. </p><p>The transformer should be rated for 230V primary voltage and 12V secondary to feed the controller. I bet you can find a wall transformer with same specs where you live. </p><p> RLY1's contacts should be rated at 230V in order to energize the coil of the new contactor replacing the starter in your motor box. </p><p>The parts required for this controller are already listed somewhere in the instructable. </p><p>rlarios</p>
<p>automated_engineer,</p><p>Notice on circuit 2 in step 2 of instructable, how power comes into the circuit breaker (240V at bottom right of schematic), then the contactor's contacts. The contactor in that drawing has two poles (just like your starter's). The blue and red wires that go into the top terminals of your existing starter would go to the line side of contactor. The wires that come from bottom terminals of your existing starter would go to the load side of new contactor. That's all you would have to do to your existing box. </p><p>You would have to wire a circuit to feed the contactor's coil (PR1 in circuit 2 of step 2), which would be switched on/off by RLY1. As you have 230V supply, you should wire this circuit to your box's 230V input instead of the plug shown in same schematic. </p><p>rlarios</p>
thank you rlarios.. I will design that circuit and when necessary ask you about the doubt... if u can send me a roughly sketch of the circuit in my case.. how the component will be placed.. I will appreciate that.. my email id- syedshahbazkhalid@gmail.com. and any link or document related to that..
<p>What do you need help with? </p><p>The controller or your starter box? </p><p>rlarios</p>
I need a complete rough schematic of all the component to be placed including my starter box.. and all the parts that I maybe needed to built my controller. will it be the same as mentioned in this instructables. or in my case I may need some less.. kindly reply. with a rough sketch also.. that will be much easier for me to understand.. thank you.
this pic might be helpful to you.. yes the starter is connected to the contactor and then the contactor is connected to the main supply that is 230 vac 50 hz..
the starter is connected with the main supply..that is approx 230v ac.. 50 hz.
<p>Are both tanks filled up simultaneously? Once we know how to turn on/off the pump, the circuit you want is as easy as this instructable's.</p>
yes I want the motor to start itself when the level reaches to a minimum position..and turn off when the tank is full...suggest with some simple wiring diagram.. and give me reference of the video or document on how to do it. if possible . thank you for your prompt response.. glad that I am having someone to guide me.. appreciate your effort and may almighty bless you.
yes, second tank is connected with a pipe which is on the bottom of the first tank..
Hi, I want to automate my submersible pump with level controller, will this design and circuitry be the same in case of submersible pump with floater switch? Kindly guide through the process.. As I m new to this and want to start my first project.. I will need the circuit design along the component used in this process with specification... I will appreciate it...thank you.
Hi automated_engineer, <br><br>Do you have the specs of the submersible pump you want to use? <br><br>rlarios<br>
I am waiting for your response.. Hope you will guide through the process..
I am waiting for your response.. Hope you will guide through the process..
<p>Hi ! I am new to the world of electronics and wish to make a similar circuit with some more requirements. Could u please help in suggesting a simple, cheapest, durable and an automated solution (with maximum safety) for prototyping the circuit below? Thank You !</p><p>I have two AC motors, one for storing water in underground tank and the other for filling up overhead tank.</p><p>I start storing water in the underground tank once it comes during designated timings on alternate days only and it takes 8-10 hrs for tank to fill completely.</p><p>Sometimes it even happens that pump for underground tank is left running (not knowingly) and the water supply from utility during the designated timings is over while filling up the tank. In this scenario, the motor uselessly runs, until someone physically see the the flow of water and then switches it off.</p><p>After I see that there is substantial amount of water present in the sump, then only i switch on the other motor to fill up overhead tank or it would burn down the motor. The tank fills up in 90mins, if it's completely empty. In this scenario too, one has to be there in time to switch off the motor once it has filled up completely to prevent overflow.</p><p>For this circuit, I would like to know the level of water using 5 LED indicators (EMPTY, 1/4, 1/2, 3/4, FULL) for both of my tanks.</p><p>More importantly, a manual switch in the circuit would be its plus point. So that if the circuit is malfunctioning, I would be able to connect the motors directly to mains.</p><p>Both are 2 HP motors and operate in 220V AC</p>
Hi there zohaib_97,<br><br>Unless I missed something, the only pump you need automated is the underground pump. This means that the overhead tank can be controlled with the circuit shown here in this instructable. <br><br>The underground pump can be controlled by a circuit similar to the &quot;pump protect&quot; portion. As this pump needs to come on only when water is available from the utility every other day at designated times, whenever water is unavailable, this pump won't come on. <br><br>You can always place a switch in parallel with relay contacts to turn pumps on and off in case of control circuit malfunction. <br><br>For water level monitoring you can place electrodes at your required levels and each electrode will be the input to a CMOS gate of some sort (like the ones in the CD4001 IC) which in turn could drive a transistor to turn on an LED.<br><br>Let me know if you are in agreement with this unless corrections are needed so either I help you designing it or you do it yourself.<br><br>rlarios<br><br><br>
<p>Hi rlarios</p><p>Thank you so much for showing support, really appreciate your efforts.</p><p>I agree with you, whatever u said above. Although, this instructable covers the requirement of automating overhead pump, but for the underground pump, can you please help me in designing the the circuit?</p>
Sure, I have one question, though. Where does underground pump get water from? A pipe, another reservoir? <br><br>I'm thinking that the underground pump can be controlled the same way the overhead pump would. After all, you would like underground pump to run until underground tank is full or until utility water runs out, wouldn't you? Being this the case, your only problem would be where to place sensors. <br><br>rlarios<br>
<p>Hi rlarios, thank you for your support.</p><p>The pump for storing the water underground (in our reservoir/sump) gets water from utility company though their underground running main pipe.</p><p>I would like to implement both of the conditions for underground pump. This is because, may be underground tank gets full first but utility water is still coming in its timings. Or it may also be possible that utility water runs out first but the tank is still not filled up completely.</p>
Do you have access to place a sensor on your underground pump's succion port? That would be necessary in order for the control to turn off this pump when you run out of utility water
<p>Hi rlarios,</p><p>Yes, i do have access there. The images are attached below.</p><p>Thanks</p>
<p>Hi rlarios,</p><p>Good day to you !</p><p>I was just thinking that the circuit is uselessly becoming complex by adding time delay circuit, and other conditions that I wished to implement. So to make it an easy one, I will physically switch on the underground pump in alternate days.</p><p>Adding the electrode on the suction port will help the system to switch off the pump once the water coming from the utility ends. Secondly when water in the underground tank reaches higher level, the motor would also end to run.</p><p>Could you please help me design the circuit so that I incorporate it?</p><p>Thanks alot</p>
<p>This is a block diagram of how these two controls could work. </p><p>This way, underground pump would come on only when Utility supply water is available AND underground tank level is below LOW level electrode.</p><p>Overhead tank water control would work as usual.</p><p>Let me know whether this would work for you and also the reason underground pump is necessary.</p><p>Good night.</p><p>rlarios</p>
<p>Thank you so much for your support, the way of your explanation in block diagram, the way you asked your friend as if it&rsquo;s your own work, I don't have words to thank you, &amp; it means alot to me.</p><p>The main reason of adding a suction pump is due to the poor distribution &amp; pressure of main utility supply, therefore an added pump helps to fill up the reservoir quickly.</p><p>In my scenario, since I don&rsquo;t have direct access to main utility pipe, the sensor placed on the suction port can only sense the availability of water, after the suction pump is switched on physically in its timings. If I would have direct access to main utility pipe, then adding a sensor there would have solved my issue without physically switching it on. Is it possible that we can add an IC/program to open the pump in between timings programmed? This would make the circuit switch on in the designated timings and placing a sensor on the suction port will help to switch it off, once the water is unavailable.</p><p>In the underground tank, a mechanical float valve like in the toilet is already there to stop the flow of water from utility once the tank is almost full. But in order to automatically stop the motor to run, I will have to place HIGH 2 near float valve.</p><p>Like in the Overhead Tank Control, I don't want LOW 2 to work similarly for Underground Tank Control, i.e to start the underground pump, once it reaches below LOW 2 level, however I only want it to be used for indication purpose.</p><p>Can you please tell what u mean in overhead tank control by &quot;Depending on which gate is faster on S-R Latch circuit, the pump may or may not start when water level is between HIGH and LOW level electrode&quot;?</p><p>It may happen that the overhead pump has just started to work after the water level reached to LOW electrode. The pump was only able to run &amp; fill only half level of the tank and there comes power load shedding. In this scenario, if the water level hasn't changed (i.e half level) and the power resumes back, then would the system resume or it will wait till the water level reaches again to LOW electrode?</p>
<p>Hi there Zohaib_97,</p><p>Sorry for not coming back to you sooner. I have been busy working in the field lately.</p><p>Well, your message looks rather long, I guess your only concern would be the operation of the S-R latch circuit, right?</p><p>If you observe the slide show when both scenarios are explained, it happens that both situations are valid when both inputs are zero. However, I did some testing after I posted the slide show some time ago and noticed that pump practically always starts when water level is between High and Low level electrodes.</p><p>I believe this is because the extra gate used to invert High level input delays the operation of the upper gate of the S-R latch. Nevertheless, don't take my word for it. I would suggest that you do your own testing to make sure that the pump will always start when such condition exists. You can build your circuit in a proto board and simulate the conditions with a shallow container with water.</p><p>Regarding the &quot;timing&quot; that you believe you require, you can always use a programmable controller such as Arduino Uno if you want. Unfortunately, I do not have all the details (other that your own description) unless you could provide a schematic diagram showing how it is that you are not connected directly to the utility pipe and yet your pump depends on it.</p><p>Good luck</p><p>rlarios</p>
<p>Hi rlarios,</p><p>Hope you are doing well in your field... &amp; no sorry, infact thankyou so much for your reply.</p><p>I have attached a hand drawing describing the distribution of water to our home through main utility pipe. Hope it covers what I wanted to describe.</p>
Zohaib_97,<br><br>I just got an email today March 31st from instructables saying that you had posted this message. Do you still need help on this? <br><br>rlarios

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