Case Study: Investigation into Low Water Flow and Tripping Pumps: Analyzing Causes and Solutions


Client: Private Club located at Rohtak, Haryana State, INDIA

Complain: The pump was tripping & water flow was low


The MDH-36A is a self-priming mono-block pump, especially designed for application which required robust performance under extreme conditions. These pumps can be used at:


  • Residential bungalows
  • Car Washing
  • Sprinklers in lawns and gardens
  • RO water treatment plants
  • Community water supply
Lubi Self Priming Pump MDH 36 A


A large private club located at Rohtak had installed our MDH-36A self-priming monoblock pump for various purposes.

On a certain day, one of the employees noticed that the pump was not functioning as efficiently as before.

Additionally, they also observed that the pump was tripping quite frequently. The manager of the club immediately called us on our toll-free helpline number to register a complaint.



  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.

At the appointed time, our service engineer arrived on location and started the preliminary checks to determine the problem.

  1. Our service engineer first tried to start the pump but it got tripped.
  2. He then checked the pipeline to see if there was any leakage.
  3. He then proceeded to verify the bypass valve to ensure that it had not been left open by mistake.




  1. When the pump got tripped, our engineer thought of checking the voltage taken by the pump using a clip-on meter. He did so and found the reading to be 273V. This indicated that there was some problem with the (incoming) power supply.

    Pump is Getting high power
    Pump is Getting high power

    This was the primary reason the pump was getting tripped. However, such heavy power could not cause any problem to the pump as we have a “thermal overload protection” inside this pump, to protect the winding from such instances.
  2. The customer had not installed a bypass valve. Usually, a bypass valve is installed to ensure that the customer may get water supply even when the pump fails.

    Note: The bypass valve must be kept closed when the pump is working.
  3. Our engineer also observed that the customer had installed a 0.5” x 0.5” suction and delivery pipes on this pump which had a suction and discharge pipe size of 1” x 1”. Also, rather than standard pipes, the customer had installed flexible pipes used in geyser machines.




Our technician explained to the customer that the delivery and suction pipes were not as per the guidelines specified by the company. They would have to change it according to the size of the suction and delivery pipe of the pump i.e. 1” x 1”.

He also suggested the customer to have a talk with their local power company to find out why the power supply to their club was more than specified limits.

Till the time the (excess voltage) issue was resolved, they could install a good stabilizer for smooth functioning of the pump and to prevent any untoward incident.

The customer made the changes as recommended by our service engineer and their pump started operating smoothly without any problem.



  1. The size of the suction and delivery pipes should be exactly similar to the size of the pump’s suction and delivery pipes.
  2. Our MDH-36A pumps have inbuilt “thermal overload protection” to protect the winding from any damage due to power fluctuations. However, it is always recommended to monitor your power supply to avoid any disruptions in pump operations.


Frequently Asked Questions (FAQ’s):


Q.What is the recommended power supply for the single-phase MDH-36A self-priming mono block pump?

A.The ideal power supply for the single-phase MDH-36A self-priming mono-block pump is 180 to 230 volts.


Q.What could be the possible reasons for low water pressure?

A.There could be many reasons for low water pressure. One of the main reasons could be leakages.

The water pressure could also be affected if someone accidentally left the bypass valve open.


Q.What is a bypass connection in a pump system?

A.A bypass connection connects the suction and discharge pipes to guarantee water supply in the event of a pump failure. When the pump is running, the bypass valve needs to be kept closed.



The following measures can ensure that your Self-Priming Mono Block Pump lasts longer with little or no downtime.


  1. Always ensure your MDH-36A self-priming mono-block pumps get continuous (Single phase) power supply of 180 to 230 volts.
  2. The winding and insulation of the pump should be regularly checked using a megger meter
  3. Our self-priming pumps can lift water to a height of 6 meters (approximately 18 feet) without the need to fill the suction line with water.
  4. Any kind of leakage can impact the flow and pressure. It is advisable to check the nuts and bolts of the pipe, to ensure they are tightened properly.
  5. Always run the pump at the duty point as declared by the company.
  6. Always check the movement of fan (behind the pump) before switching on the pump. It should not be jammed or obstructed in any manner and should rotate clockwise.
  7. Self-priming pumps work better with soft water rather than hard water.
Final Words:


It is advisable to follow the guidelines provided by the dealer while buying or repairing the pump.

You may also refer our user manual or call our toll-free number for assistance.