Overvoltage Leading to Water Lifting Issue in a Submersible Pump: A Case Study with Detailed Analysis and Solutions


Client: Farmer at Gwalior, Madhya Pradesh


Water Filled Borewell Submersible Pumpsets - LRS Series
Lubi's 4″ Water Filled Borewell
Submersible Pumpsets (LRS Series)


Our customer is a prominent farmer who has been utilizing our Rainbow-PS Submersible Pump (LRS-10H) for irrigation purposes. The LRS-10H, a 1.0 HP pump, is a high-performance pump capable of lifting water from depths of up to 43 meters.

One of the customer's workers observed that the pump was not functioning properly - failing to lift water as needed. The worker promptly informed the customer, who immediately reached out to us through our toll-free helpline number to report the issue.



  1. Customers can register a complaint by calling our toll-free number, after which they will receive a text message with information about the complaint as well as the contact details of our service engineer.
  2. Our Engineer usually calls up to fix an appointment as per the electricity schedule of the area - as there are frequent power disruptions in some places.


Our service engineer reached the site as per the pre-scheduled appointment. 


Nameplate Of The Pump
Nameplate Of The Pump


Our engineer followed standard protocol and initiated his inspection by examining the pump's power supply.

He meticulously tested both ends of the panel to ensure that sufficient power was reaching the panel and whether the motor was receiving appropriate power from the panel, using a clip-on meter, and checking the ampere reading on the panel.

Next, he utilized a megger meter to verify the insulation of the pump.



During the preliminary tests, our engineer observed that the power supply to the pump was at 302 volts, which was higher than the recommended voltage for a single-phase power line.


Pump was getting high voltage
The power supply to the pump was at 302 volts


Using a megger meter, our engineer measured the insulation resistance of the motor and found the reading to be zero, which indicated that the motor had burned out.



On inspecting the pump, our engineer felt that the motor had burnt out due to high voltage supply. He informed the customer that the motor needed rewinding, and that the pump also needed to be serviced for optimal performance.


The client agreed to the repair and servicing work, and the pump was taken to our authorized service center. Our experienced technicians did an excellent job of rewinding the motor and servicing all the parts of the pump, ensuring that it met all the performance benchmarks set by our company.


After the repair and servicing work was completed, the pump was returned to the client. The client called our engineer to reconfirm that everything was working as expected.


Our engineer reached the site and conducted some preliminary tests, only to find out that the single-phase power supply was still quite high (above 300 volts). This could again cause damage to the pump.


To protect the pump from voltage fluctuations, our engineer recommended that the client request the power distribution company to regulate the voltage. Additionally, our engineer suggested that the client use a stabilizer until the voltage was regulated, so that the pump would not be impacted by voltage fluctuations.


With these steps taken, the pump was able to operate optimally once again, allowing the client to irrigate his fields effectively.



  1. The single-phase Rainbow-PS Submersible Pump (LRS-10H) requires an ideal power supply of 180 to 230 Volts.
  2. Power fluctuations can cause severe damage to all electrical appliances, including the pump.
  3. Always ensure that the submersible pump remains completely submerged in water. To prevent dry runs, consider installing external auto cut-off sensors for additional safety.
  4. Ensure there are no leakages in the pump apparatus, delivery pipeline to prevent any loss of water and for optimal performance of the pump.
  5. Always use high-quality cable for wiring to avoid any untoward incidents. Poor-quality supply cable can result in a loss of voltage and impact the pump's performance.
  6. Minimize joints in winding cable to prevent leakages and always hire a trained professional to perform the job.
  7. If there is an issue with the push button on the panel or if the capacitor is weak, it can result in starting problems for the motor. To resolve this, it is recommended to replace the faulty push button or capacitor with a new one.
  8. If a submersible pump is experiencing low discharge, there could be several potential causes. Firstly, the non-return valve (NRV) flap may not be opening properly. Additionally, the pump may not be receiving an adequate power supply, or it may not be fully submerged in water. Finally, impurities may have accumulated in the strainer.

    To address these issues, it is recommended to repair or replace the NRV, ensure that the pump receives adequate power supply by using a stabilizer, properly submerge the pump in water, and clean any impurities from the strainer.
  9. Make sure your pump operates at the duty point declared by the manufacturer for maximum efficiency. Please contact our customer support team to learn more about duty points.
  10. Use ohms and Megger Meters to check the motor's continuity, insulation, and resistance.
  11. Regularly inspect and service your pump to detect debris in the strainer or any other potential issues beforehand.


For smooth and uninterrupted working of your pump, always follow the instructions and standard operating procedure issued by the manufacturer in the user manual.