Submersible Pumpset Timer 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.

The Request

100mm(4")borewell submersible pumpset

Power:3 phase A.C
Rpm :2850

Rpm :2850
No.of stage:45

Sir i want to run the above mentioned 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. So i need a AC circuit to operate automatically
timely for 1 hour running & 1 hour idle.

Please provide a circuit to operate without any drawbacks because if anything
happens wrongly need to spend more money & time to resolve it.More than that only source of water for us(borewell only).


The Design

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


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.

5 thoughts on “Submersible Pumpset Timer Circuit

  1. Have questions? Please feel free to post them through comments! Comments will be moderated and solved ASAP.
  2. 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.

  3. 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.

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