How to Check a Submersible Pump with a Multimeter

This site contains affiliate links to products. We may receive a commission for purchases made through these links.

Do you have a sump pump in the basement? You are possibly very acquainted with submersible pumps. In case you didn’t know, submersible pumps are run by hermetically closed motors and are used to pump liquid that they are submerged in. The pump runs by driving the liquid it is submerged in up to the surface. 

Similar to a centrifugal pump, it is composed of an impeller and casing. The closed motor initiates the impeller to attract water up into the pump. The force of the rotating impeller against the casing delivers the water out and around the pump and up a hose or pipe to the surface. 

Submersible pumps help prevent problems with pump cavitation. That’s where the pump starts to create bubbles of vapor and prevent proper pump function. Being submerged helps avoid that problem from happening and allows better continued usage with interruption. 

A sump pump installed in the basement is not just the only place submersible pumps are utilized. They have many applications too, and it’s vital to know what your pump needs can handle before buying and installing it. Among other applications, they are typically seen in petroleum and water treatment uses and are widely utilized on construction sites, among other applications. 

Digger Deeper on Submersible Pump 

As the name says, a submersible pump is created to work with the whole assembly, composed of motor and pump, completely submerged in the liquids or medium to be processed. That kind of pump has a closed motor that is close-coupled to the pump body. 

Remember that the water-tight enclosure around that motor is normally loaded with oil to safeguard it from damage by stopping the entry of liquid that might cause a short circuit

There’s a fluid pressure at the pump’s inlet every time a pump is submerged. That condition can make higher efficiency because of less energy needed to move the fluid through the pump’s liquid path. 

How Does It Work?

A submersible pump runs by pushing liquid throughout the pumping stage. That is highly effective as the pump utilizes the head of liquid in which it’s submerged to run, and no energy is present in drawing the liquid into the pump. 

A positive impact from the pump being submerged is the motor is cooled by the liquid surrounding it, stopping it from overheating. 

Most submersible pumps in the gas and oil sector operate work based on the Electric Submersible Pumping principle. That’s a cost-efficient way of lifting massive volumes of fluids from deep wells. Moreover, the motor utilized in an ESP system is created to work under high pressures and temperatures. They also need special electricity cables and can be costly to operate. 

What are the Common Uses of a Submersible Pump?

Remember that submersible pumps are highly dependable and can work in harsh environments. They are made in strong iron castings and safeguarded against any corrosion with coated epoxy.

You will find many different uses of such pumps, including but not limited to:

  • Gas and oil 

Most submersible pumps in the gas and oil sector work based on the ESP principle. That’s a cost-efficient way of lifting massive amounts of fluids from deep wells. 

  • Mining

Mines utilize ESP submersible pumps created uniquely from those utilized in the gas and oil sector. They need to contend with harsh conditions as mine water is extremely acidic and brings suspended solids.

  • Wells

Boreholes and water wells use such pumps to lift the water to the surface. The gas and oil industry employs ESP submersible pumps to elevate oil to the surface.

  • Dredging

Such pumps are also utilized by port authorities to scour a harbor. They should be specifically created to deal with liquids with high solid content.

  • Sump pumping

Did you know that submersible pumps are often utilized to get rid of water, built up in a low-lying area or pet where water could accumulate? A good example of this is getting rid of the tailing ponds from mining operations or eliminating water from the building’s basement because of flooding.

  • Sewage treatment

This application needs submersible pumps like grinder pumps, which could send solid material without disruption to discharge from the pump inlet. Such pumps often lower sewage material to particles for hassle-free management and downstream treatment.

  • Wastewater

Furthermore, submersible pumps are normally utilized in the wastewater and grit industry. They are often utilized in lift and pump stations as they are less expensive and compact to install, unlike other pumps.  

How to Check Your Submersible Pump

Here are the steps you need to follow to check your submersible pump:

  • Turn off the power supply of the pump. Disconnect the outer cover on the motor and lift off the cover. 
  • Disconnect the internal waterproof cover protecting the submersible pump motor. Disconnect the screws from the cover and lift it off. 
  • Find the two wired terminals on the submersible pump. One is labeled – for negative and + for positive. Carefully read the labels on the pump motor’s side to learn the voltage it uses.
  • Turn on your multimeter. Attach the pump to the power supply and turn on the pump. 
  • Test the power getting to your pump using your meter. Insert the sensor on the end of the black wire on the terminal’s negative. Put the sensor on the red wire’s end into the pump motor’s positive terminal. 
  • Read the meter’s reading. The power is not getting to the meter if it reads zero or above. Did you receive a reading that’s similar to the specific voltage on the pump? It means the power is getting into the motor. 

Final Thoughts

To sum up, submersible pumps have a broad spectrum of ratings for energy use, pumping seed, and capacity. Some of them can be utilized interchangeably for a wide array of uses when pumping thin liquids. 

Meanwhile, pumping applications and viscous liquids at great depths need stronger pumps, which are created to allow them to work appropriately. 

Liquids with a greater solid content, abrasive and corrosive fluids pose a specific issue, as do liquids having solid material, which could cause damage to the pump. Every application poses its fair share of challenges.

About The Author