What can be cooked from squid: fast and tasty

Now we will figure out what a water flow sensor is for (also called a “flow switch”) and look at the principle of its operation. You will also learn what types of these sensors are and how to install it yourself.

In everyday life, emergency switching on of the pump without water sometimes occurs, which can lead to equipment failure. Due to the so-called "dry running", the engine overheats and parts are deformed. In order for the pump to function at maximum efficiency, it is important to ensure the supply of water without interruption. To do this, you need to equip the heating and hot water supply system with such a device as a water flow sensor.

Water flow sensor

Device and principle of operation

The water flow sensor is a device that monitors the pressure inside the water supply system, it is connected to the pump through pipes.

Standard water flow sensor circuit:

• relay;
• a set of plates;
• inside the device there is a wide chamber;
• a small float, which is placed inside a fixed flask;
• feed channel at the output;
• most models are equipped with an adjusting cock installed at the outlet.

The principle of operation of the sensor: when there is no liquid flow, it automatically stops the pumping station and does not allow “dry running”, and when water appears, it starts the device.

Application area

Water flow sensors are usually found in devices where it is necessary to constantly monitor the life support system and observe a certain mode of their operation.

Most often, water flow sensors are used in boilers operating on gas. Modern gas boilers equipped with such sensors are used for both heating and water heating.

The device, which is located on the tap water supply pipeline, when water enters, sends a signal to the boiler control board and works circulation pump stops. Then the board turns on the nozzles responsible for heating the running water, and the water in the heat exchanger begins to heat up. When the tap closes, the sensor notifies that the water supply is suspended.

Most households are equipped with autonomous water supply systems, thanks to which you can have the most comfortable conditions.

The function of the water flow sensor is that when any of the devices connected to the water supply system is turned on, the sensor turns on the pump and water starts to flow.

When choosing a water flow sensor, be sure to consider the throughput of devices and their dimensions.

Types of water flow sensors

By type of design, relay and fitting devices are distinguished. In addition, there are varieties according to the level of pressure.

Relay type water flow sensor used for pumps with low power. Usually these models are single-chamber. Experts note their low conductivity. Models with a vertical arrangement of plates are produced, their maximum pressure is not less than 5 Pa.

Protection systems are often used in the P48 series. Thanks to all these indicators, there are practically no water leaks, and such devices also have good stability.

The most widely used water flow sensors for pumps are choke models. Their plates are usually placed horizontally, individual samples are equipped with two valves. Their maximum pressure is approximately 5 Pa. Protection systems are most often class P58. Conductivity is directly dependent on the size of the nozzle.

Low pressure sensors are applicable for pumps up to 4 kW. The size of the chamber affects the conductivity. Most often on the market you can find a water flow sensor for a two-float pump. Their price is low and you can easily choose the right model.

High pressure models are usually available with a single extended nipple and the plates are mounted horizontally. Experts advise installing such samples in centrifugal pumps. Maximum pressure - does not exceed 6 Pa, protection system class P70.

Also, according to the mechanism of action, it is divided into:

• water sensor based on the principle of operation of the Hall sensor: signals not only the flow of water, but also the speed of its supply;
• a reed sensor operating on the principle of a magnet: inside it there is a magnetic float, which, as the water pressure increases, moves through the chamber and affects the reed switch.

The device and principle of operation of the reed switch water flow sensor

Do-it-yourself installation and manufacture

Most of the water flow sensors are present in the design of the devices, therefore, their installation is required only in the event of a breakdown and the need to replace. However, there are cases when the water flow sensor must be mounted separately, for example, if it is necessary to increase the pressure of the water supply. This is due to the fact that in the central water supply system, the pressure is low and does not reach the norm. And in order to turn on the gas boiler in hot water mode, you need a good pressure.

In such situations, an auxiliary circulation pump which is equipped with a water flow sensor. First, the pump is mounted, and then the sensor. It follows that as soon as water begins to flow, the sensor will turn on the pump and the pressure will begin to increase.

Grundfos UPA 15-90 water pressure booster pump with built-in water flow sensor

Making a water flow sensor with your own hands is not difficult. First you need to install the camera, then you need to cut out three plates, they should be mounted horizontally, there should be no contact between them and the bulb. For a simple design, one float will suffice.

It is rational to install the fitting on two adapters, the valve must withstand a pressure of at least 5 Pa.

Manufacturers

Thus, the water flow sensor is designed to secure the operation of boilers and pumping equipment.

Any electric pump pumping water from a well or a well functions normally only in the presence of a working medium. Water for this mechanism is both lubrication and cooling. If the pumping unit runs idle, then after a few minutes it may become unusable. To monitor the presence of water flowing through the pump, a dry running sensor for the pump is called. At his command, the power supplied to the pump must be turned off in the absence of water.

So, dry running is the most common cause of pump failure. Moreover, in this case it will not even be possible to perform a warranty repair if the examination proves this cause of the breakdown. Such a nuisance can happen in the following situations:

1. Incorrect choice of pump suspension height in a well or in a well. This can happen if the depth of the water tank has not been measured in advance. When the pump pumps out water to the level of its location, it will begin to capture air, resulting in overheating of the electric motor.
2. The amount of water in the spring naturally decreased. For example, a well (well) silted up or water simply did not have time to get into the well after the last pumping. After the complete pumping of water from the well, it is necessary to wait a certain time to fill the well.
3. If a surface pump is used, which is located on the water surface, then the reason for its failure may be different. There are frequent cases when the suction pipe of the pump loses its tightness. Water is sucked in together with air, as a result of which the pump motor does not receive sufficient cooling.

So, if there is no protection of the downhole pump from dry running, then the pump overheats and burns out. This applies not only to the electric motor. Modern pumps have a large number of plastic parts. Plastic, in the absence of cooling and lubrication, can also be deformed. This will first reduce the performance of the device, and then cause it to overheat, jam the shaft and engine failure. Masters are familiar with this type of failure resulting from overheating. Having disassembled the unit, you can easily find those parts that have undergone overheating.

Types of dry running sensors and features of their work

Expensive pump models already have built-in dry-running protection sensors. In particular, all pumps from the manufacturer Grundfos are already equipped with such sensors from the start. When operating cheaper units, a dry running sensor for a submersible pump must be installed additionally. Let's try to understand the intricacies of the device and the operation of various types of dry running sensors.

Water level sensors

1. Float switch. The connection diagram of the dry running sensor for the pump must be built so that its contacts are included in the power supply circuit of the pump motor. The float is afloat. When the water level drops, the float changes its location, its contacts automatically open, as a result of which the power to the pump is turned off. This is the simplest type of protection, characterized by reliability and ease of operation.

Tip: In order for the float to work on time, it is necessary to adjust it correctly. It is important that the pump body is still immersed in water when the sensor is triggered.

2. Water level control sensor. Let us consider in more detail such a dry running sensor for a pump and its principle of operation. This is a relay consisting of two separate sensors lowered to different depths. One of them is immersed to the lowest possible level of pump operation. The second sensor is placed a little lower. When both sensors are underwater, a small current flows between them. If the water level drops below the minimum value, the current stops flowing, the sensor trips and opens the power circuit.

Sensors that monitor the water level are good because they allow you to turn off the pump even before the unit body is above the water surface. Therefore, the equipment is reliably protected from damage.

Protection relay

This is an electromechanical device that controls the pressure of the water flowing through the pump. When the pressure drops, the pump power supply circuit opens. The dry running protection relay of the pump consists of a membrane, a contact group and several wires.

The membrane controls the water pressure. In the working position, it is open. When the pressure drops, the membrane compresses the relay contacts. When the contacts are closed, the pump is switched off. The membrane operates at a pressure of 0.1-0.6 atmospheres. The exact value depends on the settings. A drop in pressure to this level indicates the presence of such problems:

• water pressure has dropped to a minimum. This can happen for several reasons. Including, the loss of performance by the pump itself due to the exhaustion of the resource;
• the pump filter is clogged;
• the pump was above the water level, causing the pressure to drop to zero.

The protection relay can be built into the pump housing or mounted on the surface as a separate element. If the water pumping system includes a hydraulic accumulator, then a protective relay is installed together with a pressure switch, in front of the hydraulic accumulator.

Water flow and pressure sensors

There are 2 types of sensors that control the passage of the working medium through the pump unit and provide protection against dry running of the pump. These are flow switches and flow controllers, which will be discussed below.

1. The flow switch is an electromechanical type device. They are turbine and petal. The principle of their work is also different:

• The rotor of turbine relays has an electromagnet that generates an electromagnetic field when water passes through the turbine. Special sensors read the electrical impulses generated by the turbine. When the pulses disappear, the sensor disconnects the pump from power;
• The spade relays have a flexible plate. If water does not enter the pump, the plate deviates from its original position, as a result of which the mechanical contacts of the relay open. The power supply to the pump is then interrupted. This version of the relay is distinguished by its simple design and affordable cost.

Flow sensor example

Such blocks turn off pumping equipment if there is no water flow and turn it on if the pressure in the system has dropped below a predetermined level.

2. Flow controllers (automation unit, press control). These are electronic devices that simultaneously monitor several important parameters of the water flow. They control the water pressure, signal the termination of its supply, automatically turn the pump on and off. Many devices are equipped with check valves. The high reliability also led to the high cost of these devices.

What protection to choose?

It is not easy to choose the right version of the protective device. It is necessary to take into account several factors at the same time:

• depth of the water tank;
• well diameter;
• features of the pumping equipment used. For example, a submersible or surface pump is used;
• their financial possibilities.

For example, the simplest and cheapest means of protecting a pump from dry running is a float switch. However, it should be borne in mind that its use in a well of small diameter is impossible. But for the well, it fits perfectly.

If the water in the working tank is known to be clean, then the best option would be to use a water level sensor. If you are not sure about the quality of the water supplied to the pump, it is better to use a flow switch or a water pressure sensor.

Note: If there is a possibility of clogging the pump filter with debris or dirt, then it is not advisable to use a level sensor. It will show a normal water level, although no water will be supplied to the pump unit. The result will be a burnout of the pump motor.

We can make a small conclusion. It is possible to use a pump without protection against dry running only if it is possible to constantly control the flow of water from a well or well. In this case, you can quickly turn off the power to the pump if the water stops flowing from the source. In all other cases, it is better to play it safe by installing a protective sensor. Its price fully pays for itself, given the cost of buying a new pump to replace burned-out equipment.

Equipping their own source of water supply, each owner is obliged to take care of its additional protection. In addition, not only the well or well itself needs to be prevented from breaking, but also the equipment that performs the work: the so-called drainage systems and external pumps. For safety reasons and to reduce the risk of overheating, a water flow sensor is used, which must first be properly selected.

Incorrect operation of a pumping station installed to a reservoir may depend solely on the lack of liquid. There is absolutely no difference which body of water is used to pump water; dry running problems for the pump are relevant in any case.

The reasons for idle operation often occur due to improper installation of the pump in the water supply source, as well as its incorrect choice for these purposes (non-compliance with the technical characteristics and parameters of the well or well). To exclude overheating of the pump and its possible malfunctions, it is necessary to place the pumping device at a dynamic level, that is, in the place where the water does not decrease.

Also, the cessation of the liquid supply can occur due to a decrease in pressure in the pipeline, due to which the water flow decreases and an air plug is formed, which, penetrating into the working mechanism of the device, disables it. If the tightness of the hose or pipe is lost, similar problems may also occur.

Note! If your pump is set up exclusively for manual operation and operates from a constant source (from a local pond, river or lake), then there is no need to use an automated flow sensor. In the event that the pump is connected to small wells and does not have circuit breakers, it is worth taking care to prevent breakage.

Types of dry running sensors for pumps

In practice, there are only a few types of sensors that perform a protective function in relation to pumping equipment. Today they are divided into three main types:

Some well-type pumping stations do not require special protective additions, since they provide their own protection as factory parameters.

Dry running sensor diagram

The pressure control sensor or idle speed switch does its job using a separate principle. The flow device itself is a mechanism with switching contacts. Before installation, the relay has open contacts. To start the sensor, you need to press and hold the red button until the pressure level rises to the desired value. If the number of atmospheres is not enough, the sensor will be disabled.

Some installations have special nuts on the springs in the design, which allow you to adjust the pressure values ​​\u200b\u200bwhen the mechanism is triggered. Pay attention to how the diagram below depicts the entire process of action.

To connect water flow sensors for borehole pumps, you will need to place them in series in the power grid along with pumping equipment. When a drop in atmosphere is detected, the pump protection against dry running is activated, thereby opening the electrical network.

Attention! The installation of a flow movement relay for pumping substations in an autonomous source of water supply occurs strictly according to the concept diagram. There should not be any deviations from the indicated values, since the probability of the device malfunctioning and the protection failing increases.

How to choose a device and install it at home?

Be sure to select a flow movement device taking into account the various characteristics of your pumping equipment and the capabilities of the water supply source. Before buying and directly installing a protective relay with your own hands, be sure to get the advice of an experienced specialist.

An important step after selecting the installation of the movement of the flow is its correct installation. Be sure to ensure that the pressure switch is installed before the first start-up of the water supply system. In this case, you will be able to foresee possible malfunctions and prevent their consequences.

In order to perform a mechanical type of connection for a pressure switch, you will need skills in working with fittings. You need to cut the thread, if it is not there, and seal the structure with linen or fum tape. A special adjustable wrench will help to embed the device in the pipe. After we are engaged in connecting the electricians in the mechanism. Please note that the conductors on the sensor must be suitable in terms of power to the pump in their cross section.

Typical mistakes of masters

When arranging the pipeline with your own hands, it is important that the flow control equipment is properly connected. But unfortunately, not quite an experienced user can introduce violations into the stability of the work. To eliminate all troubles, you need to know about the typical mistakes that the wizard makes when connecting the relay.

1. The device is connected incorrectly. It also happens when the sensor is connected to the water flow meter, due to which the principle of operation becomes incorrect.
2. Leakage of joints occurs when special seals are not used or materials of inadequate quality are selected.
3. The equipment for the water supply system itself is not exactly matched, and there is a discrepancy with the technical characteristics of the pump.
4. There is no correct connection diagram, as a result of which there may be a parallel connection of the device.
Your own fountain outside the city is wonderful. Let yourself function in the garden or in front of the house! But if you decide to equip it with your own hands, it is important ...

The water supply system of a private house is impossible without a pump. But it must somehow be turned on and off, to ensure that it does not work in the absence of water. The water pressure switch is responsible for turning the pump on and off, and protection against dry running of the pump should monitor the presence of water. How to implement this protection in different situations and consider further.

What is a dry running pump

Wherever the pump pumps water, sometimes a situation arises that the water is over - with a small flow rate of a well or well, you can simply pump out all the water. If water is pumped from a centralized water supply, its supply can simply be stopped. The operation of the pump in the absence of water is called dry running. Sometimes the term "idling" is used, although this is not entirely correct.

In order for the water supply at home to work normally, you need not only a pump, but also a dry water protection system, automatic on-off

What's wrong with dry running, besides wasting electricity? If the pump runs without water, it will overheat and burn out - the pumped water is used to cool it. No water - no cooling. The engine will overheat and burn out. Therefore, protection against dry running of the pump is one of the components of automation, which will have to be bought in addition. There are, however, models with built-in protection, but they are expensive. Cheaper to buy automation.

How can the pump be protected from running dry?

There are several different devices that will turn off the pump in the absence of water:

• dry run protection relay;
• water flow control devices;
• water level sensors (float switch and level control relay).

All these devices are designed for one thing - turn off the pump in the absence of water. They just work differently and have different applications. Next, we will understand the features of their work and when they are most effective.

Dry run protection relay

A simple electromechanical device controls the presence of pressure in the system. As soon as the pressure drops below the threshold, the power circuit breaks, the pump stops working.

The relay consists of a membrane that reacts to pressure and a contact group that is normally open. When the pressure drops, the membrane presses on the contacts, they close, turning off the power.

This is what dry running protection looks like.

The pressure to which the device responds is from 0.1 atm to 0.6 atm (depending on factory settings). This situation is possible when there is little or no water at all, the filter is clogged, the self-priming part is too high. In any case, this is a dry running condition and the pump must be turned off, which is what happens.

An idle protection relay is installed on the surface, although there are models in a sealed housing. It works normally in an irrigation scheme or any system without a hydraulic accumulator. Works more effectively with surface pumps when a check valve is installed downstream of the pump.

You can put it in a system with GA, but you will not get 100% protection against dry running of the pump. It's all about the features of the structure and operation of such a system. They put a protective relay in front of the water pressure switch and the accumulator. In this case, there is usually a check valve between the pump and the protection, that is, the membrane is under pressure created by the accumulator. This is a common scheme, but with this method of switching on, a situation is possible when a running pump does not turn off in the absence of water and burns out.

For example, a dry running situation has been created: the pump has turned on, there is no water in the well / well / tank, there is some water in the accumulator. Since the lower pressure threshold is usually set to about 1.4-1.6 atm, the protective relay membrane will not work - there is pressure in the system. In this position, the membrane is pressed out, the pump will run dry. It will stop either when it burns out or when most of the water supply is used up from the accumulator. Only then will the pressure drop to critical and the relay will be able to work. If such a situation arose during the active use of water, nothing terrible will happen in principle - a few tens of liters will run out quickly and everything will be fine. But if it happened at night, they let the water out of the tank, washed their hands and went to bed. The pump has turned on, there is no signal to turn off. By the morning, when the analysis of water begins, it will be inoperative. That is why in systems with hydroaccumulators or pumping stations it is better to use other devices to protect against the dry running of the water pump.

Water flow control devices

In any situation that causes the pump to run dry, there is insufficient or no water flow. There are devices that monitor this situation - relays and water flow controllers. Relays or flow sensors are electromechanical devices, controllers are electronic.

Relay (sensors) of the flow

The flow switch is of two types - petal and turbine. Flap has a flexible plate that is in the pipeline. In the absence of water flow, the plate deviates from the normal state, contacts are activated that turn off the power to the pump.

Turbine flow sensors are somewhat more complicated. The basis of the device is a small turbine with an electromagnet in the rotor. In the presence of a flow of water or gas, the turbine rotates, an electromagnetic field is created, which is converted into electromagnetic pulses read by the sensor. This sensor, depending on the number of pulses, turns on / off the power to the pump.

flow controllers

Basically, these are devices that combine two functions: protection against dry running and a water pressure switch. Some models, in addition to these features, may have a built-in pressure gauge and check valve. These devices are also called electronic pressure switches. These devices cannot be called cheap, but they provide high-quality protection, serving several parameters at once, providing the pressure required in the system, turning off the equipment when there is insufficient water flow.

In the case of using an automation unit, a hydraulic accumulator is an extra device. The system works perfectly on the appearance of a flow - the opening of a tap, the operation of household appliances, etc. But this is if the headroom is small. If the gap is large, both a GA and a pressure switch are needed. The fact is that the pump shutdown limit in the automation unit is not adjustable. The pump will only turn off when it reaches maximum pressure. If it is taken with a large headroom, it can create excess pressure (optimal - no more than 3-4 atm, anything higher leads to premature wear of the system). Therefore, after the automation unit install a pressure switch and hydraulic accumulator. This scheme makes it possible to regulate the pressure at which the pump is turned off.

Water level sensors

These sensors are installed in a well, borehole, tank. It is advisable to use them with submersible pumps, although they are compatible with surface pumps. There are two types of sensors - float and electronic.

float

There are two types of water level sensors - for filling the tank (protection against overflows) and for emptying - just protection against dry running. The second option is ours, the first one is needed when filling out. There are also models that can work this way and that, and the principle of operation depends on the connection scheme (included in the instructions).

The principle of operation when used to protect against dry running is simple: as long as there is water, the float sensor is pulled up, the pump can work as soon as the water level has dropped so much that the sensor has dropped, the contactor opens the pump power circuit, it cannot turn on until until the water level rises. To protect the pump from idling, the float cable is connected to a break in the phase wire.

Level control relay

These devices can be used not only to control the minimum water level and dry running in a well, well or storage tank. They can also control overflow (overflow), which is often necessary when there is a storage tank in the system, from which water is then pumped into the house or when organizing pool water supply.

Electrodes are lowered into the water. Their number depends on the parameters they track. If you only need to monitor the presence of a sufficient amount of water, two sensors are enough. One - falls to the level of the minimum possible level, the second - the base - is located a little lower. The work uses the electrical conductivity of water: while both sensors are immersed in water, small currents flow between them. This means that there is enough water in the well / well / container. If there is no current, it means that the water has dropped below the minimum level sensor. This command opens the power supply circuit of the pump and it stops working.

These are the main ways in which protection against dry running of the pump is organized in the water supply systems of a private house. There are also frequency converters, but they are expensive, so it is advisable to use them in large systems with powerful pumps. There they quickly pay off due to energy savings.

The operation of modern household and industrial appliances largely depends on the correct and uninterrupted operation of electronic devices. In many ways, this state of affairs suits, however, as soon as a failure occurs, the normal rhythm of life turns into a continuous hassle. But in principle, nothing terrible happens, just one of the components fails.

It is to such components of modern household appliances that the water flow sensor belongs. A simple device that is equipped with gas boilers, autonomous water supply systems, irrigation systems, well pumps.

Like all electronic components, the water flow sensor also has the principles by which it works. In principle, everything is simple here, the whole point of his work is to signal whether there is water movement or not. The sensor is installed, for example, in a pipe. When the faucet is closed, there is no water movement, and as soon as the faucet opens, the water begins to move and the sensor is triggered, the contacts close and the signal goes to the control board.

True, it is necessary to immediately indicate that the sensor is preliminarily adjusted to a certain sensitivity threshold - this is when the movement of water must reach a certain level, for example, 1.7 liters per minute. That's when the sensor will turn on, while it will continue to work until the water supply rate drops below the mark, and then the contacts open and the control board stops receiving a signal.

Areas of use

In domestic conditions, water flow sensors have found their application mainly in devices that require constant monitoring of home life support systems and compliance with a certain mode of their operation. By controlling the water supply, motion sensors can significantly reduce the cost of maintaining a home, make life much more comfortable and safer.

For gas boiler

The main place of application of the water flow sensor in modern homes has become gas boilers. Equipped with such sensors, modern gas boilers combine the functions of a hot water heater and a heating boiler.

The water flow sensor installed on the tap water supply pipeline reacts to the beginning of the movement of water when the hot water tap is opened.

The sensor sends a signal to the boiler control board, and the electronics turns off the heating circulation pump, turns off the gas heating nozzles, and closes the water circulation valve in the heating system. And then the board turns on the nozzles for heating running water and the process of heating water begins in the heat exchanger. When the tap is closed, the sensor detects the stoppage of water movement, which is signaled to the control board.

for pump

Many modern households are equipped with autonomous water supply systems. Such systems allow you to have a level of comfort comparable to apartments in a private house, but at the same time not depend on a centralized water supply.

The system, consisting of a pump, a water tank and a control system, allows you to service all the systems necessary for a comfortable stay - automatic washing machines, dishwashers, use hot water and a toilet.

The role of the water flow sensor is that when any of the devices connected to the water supply system is turned on or water is taken, the sensor turns on the pump and the water supply automatically starts. It doesn't matter if the laundry starts, the tap in the kitchen opens or the toilet bowl goes down.

Another option for using water flow sensors is automatic irrigation systems. Here, in addition to the opening function, the flow sensor controls the amount of water used for irrigation. This function is necessary to control metered watering and avoid waterlogging of the soil. The sensor installed on the central pipeline provides information to the system control panel.

Kinds

Today, two types of water flow sensors have found the greatest application - a Hall sensor and a reed relay.

The flow water sensor, based on the principle of operation of the Hall sensor (it is also called a flow meter), is a small turbine on which a magnet is mounted. When the turbine rotates, the magnet creates a magnetic field and, like a turbine in a hydroelectric power plant, it generates small electrical impulses that go to the boiler control board. The speed of rotation of the turbine depends on the speed of the water supply, the greater the flow, the clearer the pulses. Thus, thanks to the Hall sensor, it is possible not only to signal the flow of water, but also the speed of the water supply.

The reed water flow sensor is a sensor based on the principles of a magnet. Basically, this sensor looks like this - inside the chamber made of composite material there is a magnetic float, with an increase in water pressure, the float moves around the chamber and acts on the reed switch.

The reed switch, and this is nothing more than two magnetic plates in a chamber without air, opens under the influence of the magnetic field of the float, and the control board switches the boiler to hot water mode.

Installation

Considering that most water flow sensors are structurally part of the devices, their installation is required only in case of replacement in case of failure. However, there are situations when the water flow sensor must be installed separately, for example, when it becomes necessary to increase the pressure of the water supply.

Indeed, situations often occur when there is insufficient pressure in the central water supply system, and in order to turn on the gas boiler in the hot water supply mode, it is necessary to create a good pressure. In this case, an additional circulation pump is installed, equipped with a water flow sensor.

In this case, the sensor is installed after the pump, so when the water begins to move, the sensor turns on the pump and the water pressure rises.

Overview of models and prices

Water flow sensor for pump Grundfos UPA 120

The main application is the automatic control of the pump of the water supply system. The sensor is designed to provide water supply to an individual house, apartment, equipped with an individual water supply system. Switching on the automatic sensor occurs with a steady flow of liquid in the range of 90-120 liters per hour.

The main purpose is to protect the pump from idling. The sensor is used with GRUNDFOS booster pumps of the UPA series. These units have small linear dimensions, which allows installation directly into the water supply line.

The use of a sensor allows the pump to operate in several operating modes, allowing both automatic switching on and switching on when necessary. The sensor automation turns off the pump in the event of an increase in pressure in the water supply to a normal value.

Specifications:

• power consumption - up to 2.2 kW;
• degree of protection - IP 65;
• manufacturer - GRUNDFOS;
• country of origin - Romania, China;

The price is 30 dollars.

Water flow sensor series GENYO - LOWARA GENYO 8A

Products of a company specializing in the production of various electronic devices for control systems. The model is designed to control the domestic water supply system pump based on the actual water consumption. The main feature of the sensor is to control the pressure in the water supply during operation. The LOWARA GENYO 8A sensor is designed to start the pump when the water flow reaches 1.5-1.6 liters per minute.

Specifications:

• the pump is started at a water flow rate of 1.5 liters per minute;
• operating voltage of the sensor - 220-240 V;
• current consumption frequency - 50-60 Hz;
• maximum current consumption - 8A;
• power consumption - up to 2.4 kW;
• operating temperature range - 5-60 degrees Celsius;
• degree of protection - IP 65;
• manufacturer - LOWARA ;
• country of origin - Poland;

The price is 32 dollars.

It is intended for installation in gas double-circuit coppers of the Immergas trademark. Compatible with models: Mini 24 3 E, Victrix 26, Major Eolo 24 4E | 284E. The flow sensor for hot water supply is designed for installation in gas boilers of the Immergas brand of chimney and turbocharged versions. The flow sensor is made in a plastic housing with a threaded connection. Hall sensor 1.028570 allows you to get water at the outlet of the hot water circuit with a stable temperature,

Price $41.

Liquid flow switches are presented, designed for continuous monitoring of the presence of water flow and various liquid media in the pipeline. The liquid flow sensor is set to a predetermined value and, when the flow rate (flow rate) decreases, it generates a discrete signal at the output of the device. The liquid flow switch, depending on the principle of operation, can use the mechanical principle of measurement, for example, a water flow switch with a spring-loaded valve, a vortex (Vortex) or electronic (for example, a calorimetric water flow switch). Each type has its pros and cons, and different flow switch options may be suitable for each specific task. Electronic flow sensors are more expensive, however, more reliable and versatile than mechanical flow sensors. A new addition to IFM Electronic's product range are vortex flow sensors. Simplicity of design, reliability and low cost compared to flow sensors operating on other principles are all the advantages of vortex water flow sensors.
To control and measure the flow rate of liquid media, liquid flow sensors with an analog output signal are designed; in this case, the output of the device has a linear current or voltage signal proportional to the liquid flow rate.
For aggressive media, we recommend considering a liquid flow switch with measuring probes made of ceramic, Hastelloy or titanium. An interesting solution is flow sensors from IFM Electronic or EGE-Elektronik in a modular design: where measuring probes from various materials can be connected to the electronics unit, depending on the required task. Some electronic flow sensors can also monitor media temperatures and have a separate output for the temperature value. In the range of deliveries of IFM Electronic and EGE-Elektronik there are flow sensors for elevated temperature. In these sensors, the electronic and mechanical parts are separated, which allows the electronics to withstand elevated temperatures. For use in food production, we suggest considering electronic calorimetric flow switch sensors from IFM Electronic. Models SI6000, SI6600, SI6700, SI6800 have long been the benchmark and standard for food and pharmaceutical applications. High-quality polished stainless steel, extended operating temperature range and high reliability make it possible to recommend IFM Electronic liquid flow switches in hygienic design for food production.

Careful attitude to the equipment that provides water supply, significantly extends its working life, guarantees uninterrupted operation of the system. This requires not only timely inspection and proper care, but also equipping the pumps with a full range of protection devices. It is much cheaper to prevent the possibility of a serious breakdown than to repair or buy a new unit. Do you agree?

Installing a water flow switch will protect the engine of both surface and deep pumping equipment. Indeed, most often when a motor burns out, it is easier to buy a new pump than to change it. We will tell you how this important protective device works, how to choose it and include it in an autonomous water supply.

The article provides valuable recommendations for the installation of pump protection devices against operation in dry running conditions. The technology of customization for individual requirements has been disassembled. For a better perception of a considerable amount of information, photographs, diagrams, video reviews and manuals are attached.

In domestic water supply systems, the operation of a pumping station without water that threatens with an accident quite often occurs. A similar problem is called "dry running".

As a rule, the liquid cools and lubricates the elements of the system, thereby ensuring its normal performance. Even a short dry run leads to deformation of individual parts, overheating and failure of the equipment engine. Negative consequences apply to both surface and deep pump models.

Dry running occurs for various reasons:

• wrong choice of pump performance;
• unsuccessful installation;
• violation of the integrity of the water pipe;
• low fluid pressure and lack of control over its level, for which they are used;
• accumulated debris in the pumping pipe.

An automatic sensor is necessary in order to completely protect the device from the threats posed by lack of water. It measures, controls and maintains the constancy of the parameters of the water flow.

Pumping equipment equipped with a sensor has many advantages. It lasts longer, fails less often, consumes electricity more economically. There are also relay models for boilers

The main purpose of the relay is to independently turn off the pumping station in case of insufficient fluid flow power and turn it on after normalization of the indicators.

Design and principle of operation

The sensor has a unique device, thanks to which it performs its immediate functions. The most common modification is the petal relay.

The following important elements are included in the classical structure scheme:

• an inlet pipe that passes water through the device;
• a valve (petal) located on the wall of the inner chamber;
• isolated reed switch that closes and opens the power supply circuit;
• springs of a certain diameter with different compression ratios.

At the time when the chamber is filled with liquid, the force of the flow begins to act on the valve, displacing it around the axis.

The magnet built into the reverse side of the petal comes close to the reed switch. As a result, the contacts are closed, including the pump.

The flow of water is understood as the speed of its physical movement, sufficient to turn on the relay. Reducing the speed to zero, resulting in a complete stop, returns the switch to its original position. When setting the response threshold, this parameter is set taking into account the conditions of use of the device

When the flow of fluid stops and the pressure in the system drops below normal, the spring compression weakens, returning the valve to its original position. Moving away, the magnetic element ceases to operate, the contacts open and the pumping station stops.

Some modifications are equipped with a return magnet instead of springs. Judging by the feedback from users, they are less affected by small pressure surges in the system.

Petal relays are characterized by a large number of pluses. Among them are a simple and unpretentious design, instant response, no delays between repeated responses, the use of an accurate trigger to start equipment.

Depending on the design solution, several more types of relays are distinguished. These include rotary devices equipped with a paddle wheel rotating in a water stream. The speed of rotation of the blade in them is controlled by touch sensors. In the presence of liquid in the pipe, the mechanism deviates, closing the contacts.

There is also a thermal relay that operates in accordance with thermodynamic principles. The device compares the temperature set on the sensors with the temperature of the working medium in the system.

In the presence of flow, a thermal change is recorded, after which the electrical contacts are connected to the pump. In the absence of water movement, the microswitch disconnects the contacts. Models are characterized by high sensitivity, but they are quite expensive.

Instrument selection criteria

When choosing equipment that controls the strength of the water flow, you should carefully study its technical characteristics.

Particular attention should be paid to the range of operating temperature and pressure for which it is designed, the diameter of the thread and mounting holes, the protection class, and the nuances of use. It is also important to clarify what materials the product is made of.

Experts consider devices made of brass, stainless steel, and aluminum to be the most reliable and durable. These materials protect the structure from the critical consequences of a frequent phenomenon in plumbing systems - hydraulic shocks.

Considering different modifications of the relay, it makes sense to purchase an option made of metal. The body and working components of such devices are characterized by increased strength.

This fact allows the equipment to withstand serious loads for a long time, arising from the significant from the side of the liquid passing through the sensor.

The pressure value at which the relay operates must correspond to the power of the installed pump. The parameters of the water flow circulating through the pipeline depend on this characteristic.

It is advisable to choose a device with two springs that controls the operation of the pumping station according to certain lower and upper pressure marks.

The operating temperature range of the sensor directly indicates the possible area of ​​its application. For example, for hot water circuits and heating systems, models with a high boundary temperature are intended. For pipelines with cold water, a range of up to 60 degrees is enough

Another important criterion worth mentioning is the climatic conditions necessary for the operation of the product. This is the recommended air temperature and humidity level that the device needs to provide so that it can work with the best performance.

The maximum allowable loads for a particular device are determined by the protection class specified in the technical specifications.

When buying a flow sensor, you should check the diameter of the thread section and the dimensions of the mounting holes in the equipment: they must fit perfectly with the elements of the pipeline. The correctness and accuracy of further installation, as well as the efficiency of the relay after installation, depend on this.

Trustworthy Instruments

Among the entire range of relays, two models are most in demand, located in approximately the same price category - about $ 30. Let's consider their characteristics in more detail.

Genyo Lowara Genyo 8A

Development of a Polish company engaged in the production of electronic equipment for control systems. It is intended for application in household water supply systems.

Genyo allows for automatic pump control: starting and shutting down based on actual water consumption, preventing any pressure fluctuations during operation. Also, the electric pump is protected from running dry.

The main purpose is to control the pump and control the pressure in the pipes during operation. This sensor starts the pump when the water flow exceeds 1.6 liters per minute. It consumes 2.4 kW of electricity. The operating temperature range is from 5 to 60 degrees.

Grundfos UPA 120

Manufactured in factories in Romania and China. Maintains the stability of the water supply in rooms equipped with individual water supply systems. Prevents pumping units from idling.

The Grundfos brand relay is equipped with a high protection class, allowing it to endure almost any load. Electricity consumption in it is about 2.2 kW

The automation of the device starts at a flow rate of 1.5 liters per minute. The boundary parameter of the covered temperature range is 60 degrees. The unit is produced in compact linear dimensions, which greatly facilitate the installation process.

Liquid flow switches are installed for devices that need constant control and compliance with a certain operating mode. Often they complete the equipment at the production stage. However, there are circumstances where a separate mounting of the sensor is required.

Rules for installing relays in the system

Installing a safety device that determines the presence or absence of water flow in the system is a reasonable step in cases where it is not possible to be constantly present during the operation of the pumping equipment.

It is not required only in two cases:

1. Water is pumped from a large well with unlimited resources by a low power pump.
2. It is possible to independently turn off the unit when the water level drops below the designated norm.

The device is installed on horizontal sections of the pipeline. In this case, it is necessary to ensure that the membrane takes a stable vertical position.

The device is mounted to the drain pipeline using a threaded coupling. Usually a special socket is provided for this.

If there is no hole for mounting the sensor in the pumping equipment, you can replace it with a brass tee. In addition to the relay, a pressure gauge is connected to it, showing the current pressure in the network.

Before proceeding with the direct screwing of the device, it is advisable to seal the thread well with flax or thread sold in specialized departments.

It is better to wind it in a clockwise direction towards the end. This method of fastening increases the reliability of fixation.

In order not to damage the relay, you should screw it very carefully, slightly tightening it with a wrench. The optimal distance between the product and the pipeline is at least 55 mm

When installing the factory sensor, it is necessary to focus on the arrow shown on the case. The direction indicated on it must coincide with the direction of flow of the liquid passing through the device.

If contaminated water is transported through the pipeline, it is recommended to install cleaning filters, placing them near the sensor. Such a move will ensure the correct operation of the product.

At the final stage of installation work, the dry-running relay is connected to the electrical network:

• a wire core is screwed to the free ends of two groups of contacts;
• a ground is attached to the sensor screw;
• the device is connected to the pump by connecting two devices with an ordinary wire in compliance with.

After connecting to the network, the only thing left is to check the system's performance. The fact that the device is ready for full operation will be indicated by the increase in pressure marks on the pressure gauge and the automatic shutdown of the pump at the moment the limit value is overcome.

Almost always, manufacturing companies produce equipment with adjusted settings. Despite this, sometimes additional self-adjustment is required.

In most cases, setting up automatic equipment is not difficult.

It is advisable to adhere to the following algorithm:

• drain the fluid from the system until the pressure mark reaches zero;
• turn on the pumping unit and slowly start the water back;
• fix the flow pressure indicator when the pump is turned off by the sensor;
• start draining again and remember the indicators at which the pumping equipment will start working;
• open the relay and adjust with the adjusting bolt the minimum level of compression of the larger spring required to operate the device and start the pump (more compression increases the degree of pressure, less - reduces);
• in a similar way, adjust the compression force of the smaller spring mechanism by setting the maximum pressure limits, upon reaching which the relay measuring the water flow will turn off the pump.

After completing all the described manipulations, you should make sure that the adjustments made are correct. To do this, the pipeline is filled with liquid, and then it is drained, evaluating the reaction of the sensor while reaching the set values.

If the test result is not satisfactory, the procedure is repeated.

Having insufficient experience and qualifications, it is better to seek help in adjusting from specialists. They will analyze the specific situation, take into account the technical characteristics of the equipment and select the most correct values ​​​​of the pressure level.

In order for the pipeline through which the liquid passes to work properly and stably, a regular annual check of the flow sensors is carried out. If necessary, the setting of the operating parameters is adjusted.

Conclusions and useful video on the topic

Structure, components and principles of operation:

The process of connecting the device in stages:

Read more about how to adjust the trigger level in the relay:

A relay that controls the flow of water in the pipeline will significantly increase the usability of pumps and extend their life for a long time. It is highly undesirable to neglect the installation of a safety device, since it not only automates the operation of the equipment, but also protects it to the maximum from possible problems that occur due to idling.

Do you want to install the flow switch yourself, but are a little confused by the instructions? Please ask your questions, and we and the visitors of our site will try to help you.

Or maybe you have successfully coped with the installation and configuration of the device and want to give useful recommendations to other beginners? Write your comments in the block below, add a photo of the installation or setup process - your experience will be useful to many home craftsmen.

One of the common causes of breakdowns of circulation pumps is the so-called "dry run", when the pump continues to work, but water does not pass through it. Such work creates the danger of emergency situations, with a “dry run”, the engine overheats, parts are deformed, and the pump as a whole wears out quickly. To avoid such a problem, manufacturers offer booster and circulation pumps with a flow sensor.

Why do you need a flow sensor?

The flow sensor is a device that determines the movement or stop of the flow of the working medium in the system to turn on and off the circulation pump. Today they produce models with both built-in and external sensors. They not only perform the function of protecting the pump, but also ensure that the optimum pressure is maintained in water supply and heating systems.

The principle of operation of the sensor is that it controls the power of the water flow and starts the pump when the water flow rate reaches 1.5 liters per minute, when the speed drops below the set value, the sensor turns off the pump.

Thus, it provides several advantages at once:

• allows the pump to operate in automatic mode;
• avoids running the pump "dry", since it starts the system and raises the pressure in it only when necessary;
• automatic on and off makes the pump much more economical, reducing energy costs.

The cost of models with a sensor is slightly higher than that of conventional pumps, but they are reliably protected from breakdowns, more reliable and durable.