Pump running dry – effects, causes and best ways to protect it

Pump dry running: causes, effects and effective protection

Dry running This is one of the most common problems related to the operation of water pumping devices. It happens when the pump is working without enough fluid, which can lead to serious problems pump damage and shortening its service life. In modern installations it is used pump safety devices, such as water level sensors, water level transmitters or type systems SK-13, which automatically they turn off the pump if the liquid level drops. Correct pump protection it is an investment that allows you to avoid costly repairs and seizure of devices.

What is dry running and why is it dangerous?

Dry running occurs when the pump sucks in water with air or no access to liquid at all. This usually happens when the water level in the well or tank is too low. As a result pump operation occurs without adequate cooling and lubrication, which causes overheating deep well pump engine and accelerated wear of working elements. Dry running is particularly dangerous in the event of operation of deep well pumps, where breaking the water table can lead to seizing of deep well pumps and complete damage to the rotors.

Definition and mechanism of dry running

Dry running it's nothing but pump operation with no water flow or very low pressure. In most cases, it is the cause water level drop, obstructed non-return valve or poorly made pump installation. In wells where water level decreases rapidly, pump installed too high and it can draw in air instead of liquid. The solution is water level monitoring and the use of systems that enable protection of the pump against the uncontrolled interruption of pump operation. In advanced systems it is even used F&F water level transmitter to automatically respond to changing conditions water condition.

Effects of running the pump without water

Effects of pump operation dry damage is serious - from overheating of working elements to combustion pump motor, up to complete destruction of the rotors. In many cases, irreversible damage to bearings and seals occurs, necessitating the replacement of the entire device. Even short-term dry running can lead to a decline pump life by several dozen percent. That's why it applies thermal protection of the pump, which responds to overheating, as well as monitoring pressure switches installation pressure i pump pressure.

Differences between dry running and pump overload

Although dry running and overload are often confused, their mechanism is completely different. Dry running this pump operation in the absence of liquid, while overload occurs when the pump is working when too high water pressure or with excessive flow resistance. Both phenomena are dangerous for deep well pump motors and may lead to overheating. In modern systems it is used pump motor control i pump operation control, which allows for immediate stopping the pump in case of failure.

Pumps are particularly susceptible to dry running

They are the most vulnerable submersible pumps, hydrophore pumps and water pumps used in agriculture. W case of deep well pumps is of particular importance water level i well efficiency. When pumps below the mirror are not set correctly, this occurs breaking the water table and dangerous fall liquid level. It is good practice level monitoring i liquid level control using electronic sensors. It is also worth using pump motor protection and automatic systems resumption of pump operation after stabilizing water condition.

Submersible pump and the risk of lowering the water table

Submersible pump, e.g. models IBO 3 TI, must be installed so that its lower edge is properly positioned below the water table. If the installation is too low, dirt may be sucked in, and if it is too high, it may result in dry operation. It is worth remembering to choose the right one pressure switch, built-in check valve and type systems SK-13, which they constantly monitor pump operating status. Only the correct one protection of deep well pumps ensures safety, long life pump life and stable water flow even with a variable lifting height.

Various types of pumps that are used in home use, agriculture, as well as in many areas of industry, significantly facilitate the tasks related to pumping out water and delivering it to consumption points. However, for their operation to be failure-free, they must be well protected against dry running and overload, which could seriously damage them. We advise you how to protect them against the risk of failure.

Why can dry running and overload be dangerous for pumps?

Dry running may occur in both deep-well and submersible pumps. There may be several reasons for this state of affairs - from mounting the pump too close to the water table, through lowering it, to selecting too high a device's capacity in relation to the well parameters. It is very dangerous because it is usually difficult to notice that it has occurred and it may be too late to react. A pump that runs dry is unable to cool the engine, which may result in seizure of hydraulic elements and even serious damage to the control unit.

It is an equally dangerous phenomenon overload, which may have similar effects. It is most often caused by installing the pump too close to the bottom. This may result in the suction of sand and silt, which in turn leads to faster wear of pumping parts and, consequently, to dangerous overheating of the engine. Since both phenomena are dangerous for the pump, it is worth knowing how to prevent them.

The best ways to protect your pump

There are several ways that can help protect your pump from dry running and overload. These include:

- proper installation of the pump – the pump should be installed at such a depth that the lowest, dynamic level of the water table (the level of the water table determined during uninterrupted pumping with slow outflow) is at least 2 m above the pump discharge port. If the capacity of the well prevents such installation (the well is too inefficient in relation to the pump's capacity), a valve can be installed in the discharge pipeline to permanently limit the flow, or a dry-running protection device can be installed, monitoring the water level and, in the event of a risk of dry running, turning off the power supply to the unit,

- installation of pressure switches – this is quite a simple solution, the task of which is to control the pump operation and turn it off when the pressure drops,

- installation of water level sensors – this type of sensors are placed in the well and are designed to monitor the water level. When it drops to a certain level, they turn off the pump and turn it on again when the water returns to the proper depth level,

- use of modern control devices – the comprehensive solution is to use modern pump controllers. They protect and control operation of deep well pumps, submersible and surface. They protect them against dry running, voltage drop and overload,

- use of an inverter – it is a device that provides comprehensive control pump operation. Its greatest advantages include the fact that it guarantees constant pressure regardless of water consumption. In turn, eliminating pressure spikes takes longer pump life and installation resulting from the lack of the so-called water hammer. The pump with an inverter is perfectly protected against overload, low and high voltage, phase loss and asymmetry, as well as against dry running.

In summary, there are many ways to help protect submersible and submersible pumps from dry running and overload. It is certainly worth choosing at least one of them to be sure that the pumps will operate failure-free for many years.

Frequently asked questions (FAQ)

The information is educational in nature. Before installation, it is recommended to read the device manual. Dambat – manufacturer of IBO pumps.