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.

<p>Saq,</p><p>Replied though email and not sure if it will show up here in the forum or not. Try clicking the download pdf link, if not, go to the Jameco kit link below. Theory and schematic are in their docs I believe. Good stuff there. </p><p>Kid</p>
<p>can u mail me circuit diagram of this project.</p><p>shaikhsaqlain10@gmail.com</p>
<p>I built a radon mitigation system for my well water. This controller worked great!</p>
<p>hi, its a cool project, is there any way that i could get the pcb design?</p>
<p>Nice one! I have built a similar one on a bread board and tested by keeping it running for about an hour. Ionization leads to deposits on the leads/terminals inserted in water. Won't this affect performance over time and hence, required cleaning of such inserted leads periodically? If yes, is there any way to avoid this?</p>
Hi rlarious I'm back ;)<br>I was just thinking can we replace the transformer from that circuit<br>i.e, can we directly use the 12v dc adapter supply for the circuit<br><br>Can u plz tell me which components should be removed for that or how will the circuit be look like after doing that<br><br>I think those 4 diodes, 7812 voltage regulator should be removed but what about the capacitor<br>Plz help me out soon
<p>Remove capacitor as well. If wires from DC supply are longer than 3 inches, install a 0.1uF cap.</p><p>One more thing, make sure your DC PS is isolated from the mains by means of a transformer.</p><p>Good luck.</p>
Could you plz upload an image of the new schematic for the dc adapter, as I'm having some trouble with it right now<br>Thanks once again.
<p>The DC adapter you intend to use should have an isolation transformer inside. This means, there must not be any electrical connection between mains and the adapter's output such as is the case when these adapter's rely on auto transformers. The +12V DC and ground wires from your adapter would go to the +12V rail and ground line of the circuit, respectively. Forget about the 0.1uF capacitor. This is simple, just two wires from your adapter to the control.</p><p>rlarios</p>
One more thing shall i remove all the capacitors , 4 diodes, and 7812 regulator
<p>Remove D1, D2, D3, D4, C1, C2, and 7812 voltage regulator. Leave C3 installed.</p>
this design for water level control is the best i have seen in terms of simplicity of design and dedication to control limits. How can i get about 25 pcs of the pcb used in the design?, as other components is already available here.
Stevobaba411,<br><br>Unfortunately, the only source for ready built kits is jameco:<br><br>http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2169109_-1<br><br>Thanks for your comments.<br><br>rlarios<br>
Thanks a lot rlarious for such a great project<br>But i am facing some problem<br>Whenever i start the circuit<br>With or without the ic<br>The relay stays on no matter which condition it satisfies<br>So i thought to try the solution you told to vickys11<br>After doing that<br>The voltage supply for in condition i.e, when wires are dipped in water are perfectly the same reading but the voltage reading for the out condition<br>When wires are not in the water<br>The reading comes out to be 3.6 v instead of 8 to 9 v<br><br>Plz help me out soon as i need to submit my project<br><br>And yes the last question asked my vickys11 does make sense to me<br>As it will make the circuit smaller and less complex <br>Thanks a lot again.....
<p>Make sure pull up resistors are 2.2 M-Ohm. </p><p>Check your circuit very well. Also, make sure you are using a CD4001 IC. The readings you should get are consistent when tested with tap water or well water. If you're using distilled water, it won't work. Remember, 2.2 M-Ohm resistors form a voltage divider with water.</p><p>Good luck.</p>
Thanks rlarious<br>That was my mistake which i figured it out<br>Thanks to u<br><br>The circuit is working just fine but the red led is set to be turned on 24/7 no change is taking place when the inputs are been changed.
<p>Are you using same transistors and resistor values? The only function of those transistors is to turn red LED on and off depending on water level at pump protect electrode.</p>
Thanks a lot rlarios !!!!!<br>I know replying after a long time. ;)<br>Its finally working now<br><br>I just had a one more doubt<br>I made this circuit on pcb board home made using etching process<br>My ques was that<br>Can i use this circuit for a long period of time lets say 5-6 years<br>And can i turn on the circuit for 24/7<br>Can that create a problem using it for 24/7<br>Hope you will help me out soon<br>Thanks ;)
Remember the story I started this instructable with? Well, my friend and I installed the perf board circuit next to the motor starter without any enclosure, just hanging off a wire tied around a screw making sure no exposed energized parts would touch anything. <br><br>My friend said after a couple of tests: &quot;I'll come back next week to put this board into a proper enclosure.&quot; To me, this was just an experiment and Ii didn't have the intention to get any money in exchange. I forgot about the whole thing for about 4 or 5 years.<br><br>One day I got a service call from a customer close to where that water level control was installed. After taking care of business, I was intrigued as to what had been the fate of that control. Off I went to find out.<br><br>The place where this was installed was a small clinic. I got into the mechanical room and nobody was there. I went to the area where the perf board had been installed and guess what? The control was still there hanging off the same wire tied to the same screw! My friend never came back to put it into an enclosure!<br><br>A maintenance guy approached to me and told me I shouldn't be there and asked what I wanted. After telling the whole story, he said they didn't know where that controller had come from. All he knew was that they had to keep it clean and make sure it never failed. This water level control was meant to make sure they always had &quot;clean&quot; water available for doctors during surgery. Scary, isn't it?<br><br>I left the place with a feeling that something I built actually worked. And, yes, it was on 24/7.<br><br>rlarios<br><br>
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>

About This Instructable


271 favorites


More by rlarios: Troubleshoot your car battery with ATtiny. Build a simple water level control The mexican... Watt ? ? Calculate Watts on motors with Amp and Volt readings.
Add instructable to: