Case Study of Troubleshooting After Burning Winding in Openwell Submersible Pumps

Investigating the Causes of Burned Open well Submersible Pump Winding Due to Lack of Water

Client: Private Bungalow located at Rajkot, Gujarat State, INDIA

Complain: Open Well Submersible Pump Winding burnt

The LHL-151CE is a newly designed pump, especially for residential purposes. These pumps can also be used at:

• Community water supply from open wells
• Fountains
• Irrigation from canals /river belt
• Water supply for high-rise buildings

Note: This pump is recommended for drawing only clean water  

A private residential bungalow owner at Rajkot had installed our LHL-151CE Open Well Submersible Pump in their underground tank to draw water for domestic consumption.

One day, their pump suddenly stopped working. The owner of the house immediately called us on our toll-free helpline number to register a complaint.

Note: 

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 and started with the preliminary inspections to find the fault.
 

• We do provide an electric panel with this series of pumps. The technician first checked all the wires to verify if there was any loose connection, right from the mains to the electric panel to the pump’s motor. 
• He then checked the power supply using a Clip-On Meter. He checked all the points – Mains as well as the Pump’s Electric Panel (both inward and outward supply).
• He then tried to switch on the pump using the MCB in the panel, but it got tripped. He switched off the power supply and examined the MCB if it was working properly.
  
   

  

  
   
• The technician then checked the run capacitors of the panel.
• He then checked the winding of the motor using a megger meter - which showed a failure.
• He requested the owner of the house to get the pump removed from the under-ground tank for further inspection.
• After removing the pump, our technician examined the foot valve which must always be positioned upwards for optimal performance.
• He then removed the volute of the pump from the underside to check if the pump was jammed or not.
• Thereafter, the technician removed the adapter from the pump to check the winding.

After conducting a detailed inspection, our technician found that:

1. There was no problem with the power supply.
2. As soon as he tried to switch on the MCB it got tripped. However, there was no fault with the MCB. So, there had to be some other reason for the MCB to get tripped.
3. The “run” capacitors were also charging and discharging properly.
4. The foot valve was also working properly.
5. When the technician tried to check the winding, he noticed that water did not come out of motor body. He asked the owner of the house if they had filled the motor body (during installation of the pump), with water after removing the two drain plugs, which the owner denied.
    

Note : To ensure smooth operation of any open-well submersible pump, customers must remember to fill the motor body with water prior to its installation - failing which will result in costly damage from a burned out winding.

Our technician explained to the customer that he had not followed the basic instructions while installing the pump. Due to lack of water, the winding got heated and stuck to each other.

Now, the only possible way to get the pump running was to get the rewinding done.

Note : While most open-well submersible pumps require the customer to fill the motor body with water prior to installation, Now The Lubi Pumps have taken it one step further. Our innovative factory solution pre-fills each LHL 150CE & 151CE pump models with water before delivery as an added measure of protection from costly repair bills caused by neglecting this important task during install.

After the customer agreed, the technician sent the pump to our nearest service center to get the rewinding done. Once that was done, they filled water inside the motor body to keep the winding cool.

They kept filling it with water from one end until water came out of the other end. They repeated the same process again to ensure there wasn’t any air left inside the motor body.

They then conducted load testing of the pump on the testing pad.

Once the above process was done, the technician took the pump back to its owner’s site and reinstalled it in the underground tank.

They switched on the MCB on the panel and found the pump to be working smoothly.

1. An Open-Well Submersible Pump should always be installed and operated precisely as per the instruction issued by the company
2. In a water-cooled pump, it is essential to fill the motor body with water to keep the winding cool. This is done by opening both the drain plugs and pouring water into one of them until it overflows from the other hole.

Q.What is the recommended power supply for the single-phase LHL-151CE open well submersible pump?
A.The ideal power supply for the single-phase LHL-151CE submersible pump is 180 to 230 volts.

Q.How can we protect a submersible pump's winding?
A.Before installing a new water-cooled submersible pump, always open both the drain plugs of the pump’s motor and fill it with clean water from one end until it drains from the other side.

Q.What could be the possible reasons for a submersible pump to suddenly stop functioning.
A.Some of the reasons for a submersible pump to suddenly stop functioning could be:

-Pump isn’t getting enough power supply
-The pump could be jammed.
-The MCB or capacitors are not working properly. 
-The winding could have been burned. 

Q.What is the significance of a submersible pump’s control panel?

A.The main objectives of a control panel are to: 
1) Switch On or Switch Off the pump
2) Monitor the voltage and ampere of the submersible pump motor.
3) Protect the submersible pump motor from overload.
4) Provide capacity torque to the submersible pump motor.  

By installing a control panel for your submersible pump, you can: 
1) Save electricity.
2) Protect the motor from burning out.
3) Ensure your motor keeps running smoothly for a long time.

A submersible pump will last longer and work more efficiently if you follow the recommendations mentioned below, along with the other essentials mentioned in the owner’s manual.

1. Before buying a pump, properly examine your site and plan your requirements. This information is very critical for the dealer/company to recommend the most appropriate pump for your specific needs. 
2. Before installing a new pump, always open both the drain plugs of the pump’s motor and fill it with clean water, until it drains from the other side. 
3. Always ensure that the submersible pump remains “completely” submerged in water. You can also install external auto cut-off sensors (for additional safety) to prevent dry runs. 
4. Make sure your pump operates at the duty point declared by the manufacturer for maximum efficiency. Please contact our customer support team to know more about duty points. 
5. Always use good quality cable for any kind of wiring to avoid any untoward incidents. A poor-quality supply cable could also result in a loss of voltage, thereby impacting the performance of the pump. 
6. To prevent leakages in winding cable, try to keep joints minimal and always hire a trained professional to do the job. 
7. Check the motor’s continuity, insulation, and resistance using Ohm and Megger Meters. 
8. Get your pump inspected at regular intervals.

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