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Timer Controlled Submersible Pumpset Circuit

Timer Controlled Submersible Pumpset Circuit

The post details a timer circuit for submersible borewell pumpset which alternately switches the pumpset ON/OFF at a predetermined rate in order to allow the ground water sufficient time to restore at regular intervals and to ensure a consistent water supply to the attached overhead tank. The idea was requested by Mr. Siva.

Circuit Objectives and Requirements

  1. I want to run a submersible pumpset only in 3 phase with major interval of 1 hour interval duration. There is no available ground water supply for continuous running for the pump.
  2. So i need a AC circuit to operate automatically timely for 1 hour running & 1 hour idle.
  3. Please provide a circuit to operate without any drawbacks because if anything happens wrongly need to spend more money & time to resolve it.
  4. More than that only source of water for us(borewell only).

Pump Specifications

100mm(4")borewell submersible pumpset

Power:3 phase A.C
Rpm :2850

Rpm :2850
No.of stage:45

Designing the Pump Timer Circuit

The requested submersible bore well pump timer circuit can be simply built using a single IC 4060 timer circuit and a relay, as indicated below

Submersible Pumpset Timer Circuit

As may be seen in the above diagram, the IC 4060 is wired as a simple timer circuit whose timing limit is determined by the combined values of C1 and of P1/R1.

P1 can be adjusted for getting any desired delay ON/OFF at pin#3 of the IC, within a stipulated range.

Since the IC is configured as a free running astable multivibrator, the ON/OFF delays at the output pin#3 continues to toggle the transistor driver stage and the relay infinitely as long as power is available to the circuit.

If as per the specifications, P1 is adjusted to obtain a 1 hour ON/OFF delay at pin#3, the relay could be expected to switch ON/OFF at the same rate continuously as long as the circuit may remain powered.

The relay contacts can be seen wired with the 3 phase motor's contactor coil, which correspondingly operates at an identical delay rate during the course of ON/OFF switching.

This results in the switch ON and OFF of the borewell motor at a precise interval of 1 hour, which in turn makes sure that the ground water gets ample time to replenish and enable a sustained water supply for the motor to pump in.

Other time delays may be achieved for the proposed submersible pumpset timer circuit by appropriately adjusting P1, as per the given specifications or the ground water conditions.

Calculating the Time Delay

It could be determined using the formula:

f(osc) = 1 / 2.3 x Rt x Ct

The resistors at pin#10 correspond to Rt

C1 corresponds Ct


About the Author

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials. If you have any circuit related query, you may interact through comments, I'll be most happy to help!

18 thoughts on “Timer Controlled Submersible Pumpset Circuit”

  1. Howdy, Friend! Interested to Learn Circuit Designing? Let's Start Discussing below!
  2. Good day Mr Swagatam….
    I was in the market today but I couldn’t get the 5uf ceramic capacitor, I could only get 0.1uf.
    1) what modifications can I make to the R-C set up to get good time range.
    2) I also want to know if the inverse of this formula
    ( f(osc) = 1 / 2.3 x Rt x Ct ) is the given time the counter will take before it toggles between high and low positions at pin #3.
    3) If (2) is yes, is the value of the inverse of the formula
    ( f(osc) = 1 / 2.3 x Rt x Ct ) in hours or seconds?
    As always thanks for the help, hope to hear from you soon.

    • Good day Rob,
      you can use two 22uF in series with their identical pins connected together, meaning connect either (-)(-) or (+)(+) together, and use the free end terminals in the circuit.

      1) You can refer to this article where I have explained “Calculating RC Timing Components” using a simple manual technique


      2) f(osc) is the number of ON/OFF cycles per second across Ct or the capacitor at pin#9

      3) instead of using the formula you can use the step1 manual idea which is much easier and hassle free.

  3. Dear sir.
    thanks for this project, Please i need your help, how can i have a timer circuit that goes on and off contineusly and adjustable time interval, then also do you have a circuit that charges a battery and when the battery is fully charged it cuts off the supply? i need that for my emergency light.
    thanks and waiting to read from you…
    This the best website ever…. Kudus to you sir.

  4. Good Evening Sir,
    This is Vijay from bangalore, I need some clearance regarding that CONTACTOR COIL in tha circuit….??

    Is that default in relay or we have to connection separately???

    • Hi Ganesh, the contactor coil is a part of the submersible pump starter box, this coil needs to be energized through mains AC to operate the pump and vice versa.

  5. sir, Thanks for your valuable response & for the circuit design. I will surely try this circuit then i will ask any doubt related this circuit issue.

    • Siva, I am sorry I having difficulty in understanding your requirement, so please explain it again point-wise 1)…2)..3)… to make it clearer.

      However, pausing a timer during a power failure could be difficult I don't think that would be easy using discrete components.

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