HOW TO SLOW DOWN A SUBMERSIBLE PUMPWhen dealing with water systems, it’s essential to be mindful of the speed at which a submersible pump runs. Too fast, and you risk damaging your pump and not being able to regulate the pressure your equipment needs properly; too slow, and you won’t get enough water through. How, then, do you get the right amount? With a few simple steps, slowing down a submersible pump can be done efficiently, ensuring all associated machinery is working correctly. In this post, we’ll explain what precautions should be taken when preparing to adjust the speed and give instructions on manual deceleration for both single-speed and variable-speed pumps! Please keep reading for our complete guide on slowing a submersible pump safely and successfully.

Understanding How Submersible Pumps Work

Submersible pumps can be submerged in water and are designed to move liquids, such as fuel and wastewater, from one location to another. Understanding how submersible pumps work is essential when operating them correctly.

The main parts of a submersible pump consist of the motor, impeller, diffuser, shaft seal and volute. The engine is typically electric and powers the pump to turn the impeller. The impeller has vanes that pull liquid from the surrounding area and push it through the diffuser. The diffuser controls the flow of water from the pump into a pipe for transportation elsewhere. The shaft seal prevents the water from leaking out of the pump, and the volute prevents pressure from building up.

How to Slow Down a Submersible Pump

Adjusting the pump motor speed is a task that requires careful consideration to ensure not only safety but also efficiency. Several approaches can be taken to slow down a submersible pump depending on its specific design and purpose.

For instance, some pumps feature an adjustable speed control that allows for manual adjustments to the motor’s speed. Adjusting the speed control will allow you to slow down the pump without additional parts or equipment.

Another option is to install a variable frequency drive (VFD). This type of device utilizes electronic components, such as sensors and transistors, to adjust the speed of an AC electric motor. It is typically used in industrial applications but can also be installed in some residential submersible pumps.

Finally, you can also install a pressure switch to regulate the speed of the motor. This device adjusts the power supply to slow down or speed up the engine depending on water pressure levels. Pressure switches are widely available and relatively easy to install.


Slowing down your submersible pump can help you save on energy costs, reduce noise, and prolong the lifespan of your pump and other components of your system. Consider the various methods to slow it down per your equipment’s specs and functionality.