Last Updated on July 16, 2023
Have you ever wondered if your submersible pump can run dry? You can’t do it. Running a submersible pump dry can cause damage to the motor, leading to costly repairs or even replacement.
Submersible pumps are designed to operate while fully submerged in water. When water is not present, the pump will overheat and eventually shut down. Running a submersible pump dry can cause the motor to burn out, which can be an expensive and time-consuming repair.
It is important to take the necessary steps to ensure that your submersible pump is always submerged in water to avoid damage and maintain its longevity.
We will explore how to protect your submersible pump from dry run and other important considerations you should know.
Why Shouldn’t You Run Your Submersible Pump Dry?
You shouldn’t run your submersible pump dry. The reasons are as follows:
1. Damage to Impeller and Motor
2. Seal, Bearing, and Shaft Alignment Issues
3. Overheating and Motor Failure
4. Reduced Lifespan and Efficiency
5. Potential Safety Hazards
Let’s discuss the reason in more detail.
1. Damage to Impeller and Motor
If the submersible pump runs dry, it can cause damage to both the impeller and motor. The impeller relies on the presence of fluid for effective pumping.
When there is no fluid, the impeller spins without resistance, increasing friction and generating heat. This heat can cause damage to the impeller blades, reducing the pump’s efficiency and potentially causing imbalanced operation.
Moreover, excessive heat can also harm the motor, leading to premature wear, insulation breakdown, and motor failure.
The motor is an essential component of the submersible pump, and its damage can result in costly repairs or replacements.
Therefore, it’s crucial to ensure that the submersible pump always has enough fluid to avoid running dry and causing damage to both the impeller and motor.
2. Seal, Bearing, and Shaft Alignment Issues
When your submersible pump runs dry, the seals, bearings, and shafts are deprived of essential lubrication, increasing friction and potential damage.
Without proper lubrication, the bearings can become overheated and worn, causing them to fail prematurely. The lack of liquid can also cause the shaft to become misaligned, resulting in operational issues, such as vibrations, noise, and reduced efficiency.
The alignment of the shaft is critical for the proper operation of the pump. Misalignment can cause excessive wear on the bearings and seals, leading to leaks and potential failure.
To avoid these issues, it’s essential to ensure that the pump is properly aligned and lubricated before operation. Regular maintenance and inspection can help prevent these issues and prolong the life of your submersible pump.
3. Overheating and Motor Failure
Imagine your motor slowly melting, like a candle in the sun, due to the lack of cooling from the liquid surrounding it, leading to costly repairs or replacement. This scenario can happen when a submersible pump runs dry.
Submersible pumps rely on the liquid surrounding them to act as a coolant. When there is no liquid to cool down the motor, it will overheat rapidly, posing a significant risk to the motor windings and insulation, potentially causing them to break down or even burn out.
To understand the severity of overheating and motor failure, refer to the table below. It shows the symptoms, causes, and potential solutions to different types of motor failure.
By recognizing the symptoms and causes of motor failure, you can prevent it and save yourself from costly repair or replacement fees. Keep your submersible pump submerged and well-maintained to make sure it lasts.
| Type of Motor Failure | Symptoms | Causes | Potential Solutions |
| Overheating | A burning smell, discolored motor windings, melted insulation | Lack of liquid cooling, high ambient temperatures | Keep the pump fully submerged, use a thermal overload device, install a cooling fan |
| Bearing Failure | Excessive vibration, noise, shaft misalignment | Lack of lubrication, contamination, improper installation | Regular lubrication, proper installation, avoiding contamination |
| Electrical Failure | Tripped circuit breaker, blown fuses, erratic operation | Overloading, voltage spikes, moisture | Proper wiring, voltage regulation, avoid moisture |
| Seal Failure | Leaking, loss of pressure, contamination | Wear and tear, improper installation, high pressure | Regular inspection, proper installation, avoiding high pressure |
| Shaft Failure | Excessive vibration, noise, shaft misalignment | Misalignment, overloading, fatigue | Proper installation, regular inspection, avoiding overloading |
4. Reduced Lifespan and Efficiency
You’ll throw money down the drain if you let your submersible pump dry. The increased wear and tear on various components, such as the impeller, seals, bearings, and motor, can lead to frequent breakdowns and a shorter overall operational lifespan.
The impeller is particularly vulnerable to damage in dry running conditions, as it relies on the surrounding water to cool and lubricate it.
The impeller can become worn and damaged without this lubrication, reducing its pumping capacity and overall efficiency.
In addition to a reduced lifespan, running the pump dry also reduces its overall efficiency. This results in decreased pumping capacity and increased energy consumption, ultimately leading to higher operating costs.
To ensure the longevity and efficiency of your submersible pump, it’s crucial to monitor its water levels and avoid running it dry. Regular maintenance and inspection can also help to catch any issues early, preventing more significant damage and costly repairs.
5. Potential Safety Hazards
Now that you understand how running a submersible pump dry can reduce its lifespan and efficiency, it’s important also to consider the potential safety hazards that come with it.
When a pump runs dry, the heat generated by the friction of the impeller spinning against the casing can cause the pump’s seals to fail. This can result in leaks, which can lead to flooding and damage to surrounding equipment.
In addition to the damage caused by leaks, there are other safety hazards that can arise from running a submersible pump dry. Here are a few potential safety hazards to consider:
- Electrical shock: When a submersible pump runs dry, the motor can overheat and cause the insulation on the electrical wires to melt. This can lead to a short circuit, resulting in electrical shock.
- Fire: If the motor continues to run while the pump is dry, it can generate enough heat to ignite any flammable materials in the area.
- Pump damage: Dry-running a pump can cause the impeller to spin faster than it was designed to, damaging the impeller and other parts of the pump. This can lead to costly repairs and downtime.
How Do You Protect the Submersible Pump From Dry Running?
To prevent your submersible pump from experiencing a dry run, you should consider installing dry run protection devices. These devices can detect when the liquid level drops too low and will automatically shut off the pump to prevent damage. Let’s discuss in detail what you need to do.
1. Install Dry Run Protection Devices
By installing dry run protection devices, submersible pumps can be safeguarded against running dry, preventing potential damages.
These devices are designed to monitor the liquid level or pressure and automatically shut off the pump when the liquid drops below a certain threshold.
This prevents the pump from running dry and potentially damaging the motor or other components.
Float switches, level sensors, and pressure switches are all examples of dry-run protection devices that can be connected to the submersible pump. Installing and maintaining these devices is easy.
2. Maintain Adequate Liquid Levels
Make sure you’re regularly checking the liquid levels in your system and making sure they’re above the minimum to avoid any potential damage.
Running your submersible pump dry can cause severe damage to the motor as well as the impeller, leading to costly repairs or even complete replacement of the system.
The best way to prevent this is by maintaining adequate liquid levels in the pump system.
To ensure that your pump system is running smoothly, it’s essential to adjust the positioning of float switches or install additional level sensors that provide accurate liquid level readings.
These devices can help you monitor the liquid levels and take appropriate action to prevent the pump from running dry.
Moreover, proper maintenance of the pump system can prevent other issues that may lead to reduced efficiency and increased operating costs.
Therefore, make sure you’re regularly monitoring the liquid levels and keeping them above the minimum required level to ensure optimal performance and prevent any potential damages.
Does a submersible pump need to be completely submerged?
Submersible pumps are designed specifically to operate underwater, relying on the surrounding liquid to cool the motor and provide lubrication to the seals. If a submersible pump operates with inadequate liquid levels or is used out of the water, it can overheat rapidly, leading to motor damage or failure.
To emphasize the importance of submerging a submersible pump, consider the following table:
| Submersible Pump Level | Result |
| Completely Submerged | Proper Operation |
| Partially Submerged | Overheating and Motor Damage |
| Out of Water | Rapid Overheating and Motor Failure |
As the table shows, submersible pumps must be completely submerged to operate properly. Any deviation from this can result in the pump overheating and eventually failing. Therefore, it is crucial to maintain adequate liquid levels and ensure the pump is completely submerged before operation.
How long can a submersible pump run dry before damage?
A submersible pump can run dry for a maximum of 45-60 seconds before it suffers significant damage. However, if the duration of running dry is shorter, then it should not cause any major damage to the pump.
It is crucial to avoid running the pump dry for an extended period to prevent significant harm to its components. Therefore, it is recommended to keep a close eye on the pump while it’s operational and turn it off immediately if the water level is too low.
How often should a submersible pump be serviced?
Like any other mechanical equipment, a submersible pump requires regular maintenance to ensure optimal performance. To avoid potential issues, it is advisable to have the pump serviced at least once a year.
This annual maintenance checkup allows for a comprehensive inspection of the pump’s components, including seals, bearings, impellers, and motor brushes.
Protect Your Submersible Pump for Maximum Efficiency and Longevity
It’s now clear that running a submersible pump dry can hurt its performance and lifespan. The impeller, motor, seals, bearings, and shaft alignment are all at risk of damage, reducing efficiency and a shorter lifespan.
To safeguard your pump, make use of dry run protection devices and ensure adequate liquid levels are maintained. Regular servicing and maintenance are crucial for pump longevity.
By avoiding dry running and following proper maintenance practices, you can ensure your submersible pump’s reliable and efficient operation, saving you from costly repairs and replacements.
Remember, a little care goes a long way in maximizing the lifespan and performance of your submersible pump.
