Water flow switch for pump: characteristics, principle of operation, installation

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Published: 06/11/2019

Reading time: 2 min

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Modern heating boilers are equipped with electrical devices for ease of use and increased functionality. One of these is a water flow sensor for a gas boiler. The three best models, possible malfunctions and methods of application are discussed further in the article.

• 1 Where used 1.1 For gas boilers
• 1.2 For pumps

Flow sensor malfunctions

Design and principle of operation of a rotary pump

Common malfunctions that may occur during operation:

1. The DHW mode does not start, the equipment is unstable. To make sure that it is the regulator that has failed, you need to take a multimeter and measure the resistance. If it is approximately 2.5 kOhm, then according to the table this indicator should be achieved when heated to 60 degrees. But if the device is cold, then the problem is definitely in the water flow sensor. The regulator will “say” that the water is already heated and additional temperature is not needed. To fix the problem, you will have to completely replace the failed sensor. But we must not forget that it has direct contact with water and before removal it is necessary to drain all the water from the boiler (Baksi or other companies) and shut off its supply.
2. If error No. 201 appears on the indicator, this means that there is a break or damage to the wires that are connected to the regulator. For the regulator to work normally, you need to restore its original position.
3. Error No. 202 - short circuit. In this case, you need to check the device itself or the wires that are connected to it.

Recommendations for installation and configuration

A significant segment of water flow sensors for boilers is supplied complete with heating equipment, so the need for their installation arises only in the event of a breakdown, when you have to think about a commensurate replacement. A rare case when a separate installation of the device is planned is the need to increase the pressure of the liquid supplied to the system. A similar situation occurs if the central water supply is characterized by low pressure, barely reaching the needs of the boiler. In order for a gas appliance to be able to provide the proper quality of hot water supply, it must deal with good pressure.

To solve this problem, install an additional circulation pump and equip it with a water flow sensor (the components must be introduced into the system in this order). As water begins to flow, the device activates the pump, which leads to an increase in pressure.

Homemade models are made from a chamber that will be used in conjunction with three horizontally mounted plates. It is important that the latter do not contact each other and do not touch the flask.

For the simplest modifications, the introduction of one float is sufficient. The fitting should be mounted in tandem with two adapters, the maximum permissible valve pressure is 5 Pa.

What is and why do you need a water flow switch?

Generator voltage regulator relay: diagram, principle of operation

In household water supply systems, the action of a pumping station without water quite often occurs and threatens an accident. This problem is called “dry running”.

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

Dry running occurs for various reasons:

• incorrect choice of pump capacity;
• unsuccessful installation;
• violation of the integrity of the water pipe;
• low fluid pressure and lack of control over its level, for which a pressure switch is used;
• accumulated debris in the pumping pipe.

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

Pumping equipment equipped with a sensor has many advantages. It lasts longer, breaks down less often, and uses energy more economically. There are also relay models for boilers

Where are they used?

Screw pump: principle of operation, scope and design features

Flow sensors are used in devices where control of the water supply system to an apartment or private house is necessary. By installing this type of equipment on a gas boiler, you can significantly reduce your monthly payment, and the heat generator will also become much safer to use.

For gas boilers

There is a water flow regulator in all boilers (Buderus and other models). Thanks to the device, the heat generator can work as a device for heating a home and heating water.

The gas boiler water pressure sensor is mounted on the pipeline. Once installed, it begins to respond to flow as soon as the hot tap is opened.

The regulator transmits a signal to a special board installed inside the boiler. After this, the circulation pump automatically starts and the pressure in the gas injectors decreases. As a result, the water circulation valve closes. After this, the water heating nozzles turn on, and the liquid begins to warm up in the heat exchanger. After closing the valve, the mounted sensor for the gas boiler records this action and transmits the corresponding signal to the board.

For pumps

In many private houses, an autonomous water supply system is installed. This is necessary if there is often low pressure on the site and the owner wants his yard to be independent of the centralized water supply. The equipment is installed so that the water pressure in the house always remains at a high level.

The system includes:

• special pump;
• a tank where water is poured;
• control system.

You can connect various household appliances to the pump, for example, dishwashers or washing machines. In this case, the regulator is necessary for timely activation of the pump, ensuring a stable water supply.

And it doesn’t matter whether the wash has started, the tap is open in the kitchen, or water is draining from the toilet tank - the regulator performs the same functions for any type of household equipment connected to the system.

Also, the owners of the living space in question often connect the sensor in question to automatic watering in the country or in a private house. Here the device not only performs the opening function, it regulates the amount of water that should be consumed at a time.

This function is very useful if dosed watering is used so as not to over-moisten the soil. For stable operation, the flow regulator is mounted to the central pipeline, and it transmits all information to the system control panel.

Areas of use

In domestic conditions, water flow sensors have found their use mainly in devices that require constant monitoring of the life support systems of the house 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 and make life much more comfortable and safer.

For gas boiler

The main place for using water flow sensors in modern homes are gas boilers. Modern gas boilers equipped with such sensors combine the functions of a water heater and a heating boiler.

The water flow sensor installed on the tap water supply pipeline reacts to the start of water movement 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, extinguishes 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 that the water movement has stopped, 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 in a private house comparable to apartments, 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 comfortable living - automatic washing machines, dishwashers, 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 selection begins, the sensor turns on the pump and the water supply automatically starts. It doesn’t matter whether the laundry starts, the kitchen faucet opens, or the toilet cistern flushes.

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 dosed watering and avoid waterlogging of the soil. A sensor installed on the central pipeline supplies information to the system control panel.

Today, two types of water flow sensors are most widely used: a Hall sensor and a reed switch relay.

A flowing water sensor, based on the operating principle of a Hall sensor (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 station, generates small electrical impulses that are sent to the boiler control board. The turbine rotation speed depends on the water supply speed; the higher 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 water supply.

The reed water flow sensor is a sensor based on the principles of a magnet. Fundamentally, this sensor looks like this - inside a chamber made of composite material there is a magnetic float; when water pressure increases, the float moves around the chamber and affects the reed switch.

The reed switch, which 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 supply mode.

Reed water level sensor:

Water flow meter:

Sensor types

Today, the most popular and advanced water flow devices are reed switch relays and Hall sensors.

Description:

1. A flow meter or Hall sensor is a small turbine with a magnet. As soon as the turbine begins to rotate, the magnet creates a field and generates electrical pulses that are transmitted to the boiler board (for example, Ferroli).
2. The reed switch regulator also uses magnetism. A float magnet is installed inside the chamber. As soon as the water pressure increases, the float moves and begins to act on the reed switch (several magnetic plates that move apart under the influence of the float).

Design and principle of operation

The operating principle of the flow switch is based on the mechanical effect of the water flow in the pipeline on the sensor that controls the electronic circuit for turning on and off the electric pump. Relays have different operating principles and, depending on the design of the sensor, are divided into several types.

Petal relays

One of the most common types, the main elements are a petal sensor with a magnet located in the water flow and a reed switch placed in the device body and securely insulated.

As water flows through the pipeline, the vertically located petal sensor rotates along its axis and deviates from the vertical position, bringing the built-in magnet closer to the reed switch. Its contacts inside the cylinder are closed and the pump is connected to a source of electricity through a triac (double symmetrical thyristor).

If there is no water in the pipeline, the petal returns to its original position, moving the magnet away from the reed switch and thereby opening its contacts.

This leads to the cessation of supply voltage to the pump through the semistor, as a result of which it turns off.

Connecting and adjusting the sensor

The efficiency of the sensor that monitors the flow of water and controls the operation of pumping equipment largely depends on the correct installation of this device. It should be borne in mind that such a sensor, regardless of the type and purpose of the pipeline, can only be installed in horizontal sections. In this case, it is necessary to ensure that the sensor membrane is located strictly in a vertical position.

When installing a liquid flow sensor, it is connected to the drain part of the pipeline using a threaded coupling. In this case, the distance at which such a device should be located from the pipe itself cannot be less than 55 mm.

Flow sensor installation diagram

On the housing of factory water flow sensors there is always an arrow that indicates in which direction the liquid should move through them. When installing the sensor on the pipeline, you must ensure that this arrow coincides with the direction of water movement. If the sensor is installed in a system through which heavily contaminated liquid is transported, filters must be placed in front of it for the correct operation of such a device.

Electrical connection diagram

Despite the fact that fluid flow sensors are supplied from manufacturing plants with already adjusted parameters, independent adjustment must be performed periodically. For this purpose, special bolts are provided in the design of the sensors. With the help of the latter, the degree of compression of the springs is increased or decreased, setting the level of pressure at which this device will operate.

Leaf type flow sensor adjustment controls

So, to adjust the water flow sensor with your own hands, you need to perform the following steps:

• drain the water from the pipeline system and make sure that the pressure has reached zero;
• turn on the pump and start filling the system with water;
• when the pump is turned off, which occurs due to a signal from the sensor, record the value of the liquid pressure;
• Draining the liquid from the system again, record the pressure value of its flow at which the pump will turn on;
• by removing the sensor cover and using a special bolt, adjust the degree of compression of the large-diameter spring (this way you will set the minimum pressure level at which the device will operate and the pump will turn on; it should be borne in mind that compression of such a spring increases the pressure level, and weakening reduces it);
• Having filled the system again with water and starting to drain it, check whether the sensor is adjusted correctly and whether it turns off the pump at the required pressure level (if the device is adjusted incorrectly, the entire procedure described above should be repeated);
• by changing the degree of compression of a spring of small diameter, set the maximum pressure level at which the pump will turn off (the difference between the sensor response thresholds increases when such a spring is compressed and decreases when it is weakened);
• after adjusting the degree of compression of a small-diameter spring, check that this procedure is performed correctly by starting to fill the system with water and recording the pressure value at which the pump turns off (if this adjustment is performed incorrectly, it should also be repeated until the desired result is achieved).

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 operating mode.

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 the operation of the 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 has been stopped.

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 you turn on any of the devices connected to the water supply system, the sensor turns on the pump and water begins to flow.

Design features

The main tasks that water flow control sensors installed in domestic pipelines solve are to turn off pumping equipment at a time when there is no liquid in the system or its flow pressure exceeds the standard value, and turn it on again when the pressure drops. An effective solution to these important problems is provided by the sensor design, which consists of the following elements:

• a pipe through which water enters the sensor;
• a membrane that makes up one of the walls of the inner chamber of the sensor;
• a reed switch that provides closing and opening of the pump power supply circuit;
• two springs of different diameters (the degree of their compression regulates the pressure of the fluid flow, at which the water flow switch for the pump will operate).

Main components of an industrial flow sensor

The device of the above-described design works as follows:

• Entering the inner chamber of the sensor, the water flow puts pressure on the membrane, displacing it.
• The magnetic element fixed on the back side of the membrane, when it is displaced, approaches the reed switch, which leads to the closure of its contacts and the pump being turned on.
• If the pressure of the water flow passing through the sensor drops, the membrane returns to its original position, the magnet moves away from the switch, its contacts open, and accordingly, the pumping unit is turned off.

The operating principle of a flow sensor based on a permanent magnet and a reed switch

Sensors that monitor water flow are installed quite simply in pipeline systems for various purposes.

The main thing is to choose the right device, paying attention to its operating parameters and characteristics of the pumping equipment

Device selection criteria

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

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

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 common phenomenon in water supply systems - water hammer.

When considering different modifications of the relay, it makes sense to purchase a version made of metal. The housing and working components of such devices are highly durable.

This fact allows the equipment to withstand serious loads for a long time that arise due to significant pressure in the water supply from 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 its possible area of ​​application. For example, models with a high limit temperature are designed for hot water supply circuits and heating systems. For cold water pipelines, a range of up to 60 degrees is sufficient

Another important criterion that deserves special mention is the climatic conditions necessary for the operation of the product. This refers to the recommended air temperature and humidity level that the device needs to provide in order for it to perform at its best.

The maximum permissible load for a particular device is determined by the protection class specified in the technical specifications.

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

Device connection diagram

The operating efficiency of the relay greatly depends on its correct installation. It must be remembered that the device can only be installed on those sections of the pipeline that are located horizontally. In this case, you will need to ensure that the sensor membrane is in a vertical position. The correct relay connection diagram looks like this:

During installation, the sensor must be connected to the drain part of the pipe using a threaded connection. The distance at which the relay should be located from the pipe should be more than 5.5 cm.

There is an arrow on the body of the device indicating the direction of liquid circulation. When installing the device, you need to make sure that this arrow coincides with the direction of water flow in the system. If dirty water is used for domestic purposes, then cleaning filters should be installed in front of the sensor.

Rotary relays and flow type sensors

Rotary sensors are mainly used to measure and control fluid flow. Structurally, they are made in the form of a paddle wheel rotating in a fluid flow; its rotation speed is recorded by sensors. The electronic circuit allows for analog, frequency or discrete control of the operation of the equipment.

Piston devices

The piston is placed in the valve seat and, under the influence of water pressure, moves in the vertical direction to a height proportional to the force of the flow. A permanent magnet mounted on the piston approaches the reed switch and the contacts in it close. Piston devices can be installed on horizontal and vertical pipelines thanks to the built-in return spring, which returns the piston to its original position in the absence of flow.

appearance

Construction of a double-circuit gas boiler

In order to understand the principle of operation of a gas double-circuit boiler, it is necessary to understand its structure.
It consists of many individual modules that heat the coolant in the heating circuit and switch to the DHW circuit. The coordinated work of all components allows you to count on trouble-free operation of the equipment. Knowing the structure of a double-circuit boiler, you can understand its operating principle. We will not consider the design of double-circuit boilers down to the screw, since it is enough for us to understand the purpose of the main components. Inside the boiler we will find:

Design of models with two circuits: heating and DHW circuit.

• The burner, located in an open or closed combustion chamber, is the heart of any heating boiler. It heats the coolant and generates heat for the operation of the DHW circuit. To ensure accurate support of the set temperature, it is equipped with an electronic flame modulation system;
• Combustion chamber - the above burner is located in it. It can be open or closed. In a closed combustion chamber (or rather, above it) we will find a fan responsible for pumping air and removing combustion products. It is this that is the source of quiet noise when the boiler is turned on;
• Circulation pump – ensures forced circulation of coolant through the heating system and during operation of the DHW circuit. Unlike the combustion chamber fan, the pump is not a source of noise and operates as silently as possible;
• Three-way valve - this is the thing that is responsible for switching the system to hot water generation mode;
• The main heat exchanger - in a double-circuit wall-mounted gas boiler, it is located above the burner, in the combustion chamber. Here the coolant used in the heating circuit or in the DHW circuit for heating water is heated;
• Secondary heat exchanger - this is where hot water is prepared;
• Automation - it controls the operating parameters of the equipment, checks the temperature of the coolant and hot water, controls modulation, turns on and off various components, monitors the presence of flame, records errors and performs other useful functions.

At the bottom of the buildings there are pipes for connecting the heating system, cold water pipes, hot water pipes and gas pipes.

Some models of gas double-circuit boilers use dual heat exchangers. But the operating principle remains almost the same.

You may notice that the design of the geyser differs only in the absence of a heating circuit.

We found out the structure of a double-circuit wall-mounted gas boiler - it seems a little complicated, but if you understand the purpose of certain components, the difficulties will disappear. Here we can note the similarity with a gas instantaneous water heater, from which a burner with a heat exchanger remains here. Everything else is taken from wall-mounted single-circuit boilers. An undoubted advantage is the presence of a built-in piping - this is an expansion tank, a circulation pump and a safety group.

When analyzing the operating principle and design of a gas double-circuit boiler, it should be noted that water from the DHW circuit is never mixed with the coolant. The coolant is poured into the heating system through a separate pipe connected to the heating. Hot water is prepared using part of the coolant circulating through the secondary heat exchanger. However, we will talk about this a little later.

Installation of a relay on a pump or station

If installation of the device is required, the work can be done independently, especially if you have to be away and there is no way to constantly monitor the operation of the pumping equipment.

When you do not need to install a relay:

• if water is pumped from a well with a large volume, that is, liquid reserves are not limited, and the pump power is minimal;
• It is possible to turn off the installation when the water level drops.

Equipment installation rules:

It is important to monitor the membrane - the part must take a vertical position. Installation is carried out to the drain pipeline section using threaded couplings. There is a special slot for this. Before starting work, the threads are sealed with linen or other plumbing thread

Winding the thread towards the end clockwise will increase the reliability of fastening and fixation. Factory sensors are equipped with an arrow drawn on the body - this is the direction of flow, which must match during installation. When installing relays in water supply pipelines with dirt particles, cleaning filters are first installed. It is better to mount them next to the sensor to extend the service life of the device.

Testing of the installed device is carried out with connection to the power supply:

• the free ends of the contacts are connected to the wire core;
• grounding is mounted to the screw;
• the device is connected by connecting the device with a wire (watch the color of the corresponding wires);
• system functionality is checked.

Self-adjustment of the water movement sensor

The factory device is equipped with bolts, by tightening or loosening which you can increase/decrease the spring compression. Bolts will be required if you need to install the sensor at a certain pressure level at which the mechanism is triggered.

Algorithm of actions:

• drain the liquid from the system;
• wait until the pressure mark reaches zero;
• start the pumping unit;
• run the water back in the slowest mode;
• remember the flow pressure indicator when the pump relay is turned off;
• drain the liquid again, recording the indicators when the system starts operating.

Now you need to open the relay, use the bolt to adjust the compression level of the larger spring - this will trigger the device when the pump starts. The adjustment is made taking into account that strong compression will increase the degree of pressure, and weak compression will decrease it. Then the compression force of the smaller spring is adjusted - here the limit of the maximum pressure level is set, upon reaching which the relay will automatically turn off the pump.

As soon as the adjustment is completed, start the system, evaluate the results of the work when filling the pipeline and draining the flow. If adjustment changes are necessary, repeat the procedure. Checking functionality and adjusting operating parameters is an annual procedure that extends the life of the device.

DIY repair

You can fix some problems yourself. The main thing is to follow our recommendations.

Water heater does not turn on

First of all, check if there is voltage in the network. You can check this with a screwdriver with an indicator: it should light up on “Phase”, but not on “Zero” and “Earth”. If the cable insulation is damaged, it is not recommended to carry out repairs. It is better to replace the element immediately, but make sure that the new cable matches the old one in terms of parameters.

A short circuit or lack of grounding leads to permanent shutdown of the RCD. A breakdown of the heating element on the body also leads to similar consequences. In this case, the element is diagnosed and replaced.

The RCD machine could break. To confirm your guesses, press RESET on the instrument panel. Is the light on? This means food is being served. Then press TEST and RESET again. If the indicator lights up again, the RCD is working normally.

Boiler does not heat water

Check the tightness of the contacts between the plug and the socket. If everything is in order and the voltage is supplied normally, you need to check the heating element. Do you have a storage type of boiler? Then drain the water from it first. A volume of water of 50-80 liters can be removed through the tap. It is better to drain 100 liters or more using a valve.

Remove the housing from the wall. Now you need to pull out the flange to which the heating element is attached. In Ariston 80 liter models, the flange is secured with only one bolt. In other cases, you will have to unscrew 5 bolts.

Disassembly is done like this:

• Rotate the flange along the axis.
• Take it out of the tank.

• Heater diagnostics are carried out with a multimeter. Read more in the article: “Replacing the heating element in a water heater.”
• If the multimeter needle moves, the part is working. Is it standing still? You need to install a new one.

Have you noticed that the water takes longer to heat up than usual? This does not mean that the heater is broken. Perhaps the reason is scale: over time it grows in a thick layer and interferes with normal heat transfer. Clean the element with special means.

Lack of heat may indicate a broken thermostat. Perform a reset on the boiler panel. If the appliance cannot be restarted, the thermostat is faulty.

A tester will help diagnose the breakdown more accurately:

• Set the multimeter to the maximum position.
• Attach the probes to the contacts of the thermostat (located next to the heating element).
• Does the arrow on the screen move? The device is working.

There is another option:

• Heat the thermostat with a lighter.
• Set the multimeter to "minimum".
• Place the probes on the contacts.
• If the arrow moves away from zero, then the part is functioning normally.

If there is a malfunction, the thermostat needs to be replaced. Disconnect the wiring from the part and pull it out of the hole.

Installation is carried out in reverse order.

Review of famous manufacturers and prices

Several models in the $30-40 price category are considered the most famous and reliable:

1. Genyo Lowara Genyo 8A. Manufacturer – Poland. The main direction of the company is the production of electronic equipment for control systems. The relay is designed for use in domestic water supply systems and is characterized by high quality and long service life. By monitoring the flow pressure in the pipes, the sensor starts the pumping system at a water flow rate of 1.6 l/minute. The unit requires an electrical connection and consumes 2.4 kW/hour. Operating temperature +5..+60 C.
2. Grundfos UPA 120. Manufacturer's plants are located in Romania and China. The device has small dimensions, is convenient to install and is indicated for individual water supply systems. That is, it can be used both in private buildings and apartments. The device starts up at a liquid flow rate of 1.5 l/minute, completely preventing the functionality of the system at idle. The extreme operating temperature is +60 C.

The models have been tested and adapted to domestic operating conditions. Numerous reviews characterize metering sensors as durable and practical units at an affordable price.

Top 3 best sensors

Based on user reviews, there are three best devices that you should pay attention to when purchasing:

1. Regulator for the Grundfos UPA 120 pump. The equipment turns on automatically, but can be started as needed. Used in a private house or apartment where an independent water supply system is installed. The sensor will begin to function when the flow of incoming liquid is as stable as possible (range - 90-120 liters per hour). The purpose of the installation is to avoid idling of the heat generator installed in the house.
2. Genyo – Lowara Genyo 8A. The water supply system is controlled based on the actual fluid flow. Automatically monitors pressure during operation.
3. Sensor 1.028570. Can work with Immergas double-circuit boilers. Compatible with models: Mini 24 3 E, Victrix 26, Major Eolo 24 4E | 28 4E. The Hall sensor will ensure a stable outlet water temperature.

How to set pressure using a flow switch

Briefly - for 5 seconds. – press button “1”:

In this case, the “accident” lamp should blink red. This is where we entered programming mode. Now we turn on the pump, and as it works, it builds up pressure. It is clear that all taps in the house must be closed. We look at the pressure on the pressure gauge. For example, we need the water supply to be 2 atm, so we wait for the pump to build up this pressure. As the arrow on the pressure gauge shows the required pressure, press button “1” again. The pump will turn off.

We press the “2” button, thereby “driving” into the relay’s memory that at this pressure the pump should turn off.

Now we are programming the lower limit. To do this, open any tap so that the pressure begins to drop. When the pressure gauge shows the lower pressure we need, press button “1” again and the pump will turn on. By pressing button “2” we “drive” the relay into the head so that at this pressure the pump must be turned on.

Installation features

Paddle switches are mounted either at the pump inlet or at the valve inlet. Their task is to record the initial entry of liquid into the working chamber, and therefore contact with it must be detected first of all on the relay itself.

Pressure control units are installed only with the help of specialists, as they require adjustment. They are installed in the same way as the petals, by connecting the inlet to the pumping device. However, unlike conventional petals, pressure switches are almost always used in conjunction with pumping stations.

Thermal relays are rarely used separately, since the thing is too expensive. It will most likely be connected at the assembly stage of the pump itself. However, a good master will certainly be able to cope with the installation of this device. The complexity of the installation lies in the need to mount several sensitive thermal sensors, and then bring them together.

Air pressure sensors in boilers

The air pressure control relay in the gas unit monitors the combustion temperature of the energy carrier. Boiler air control sensors that regulate the supply of volatile substances to the furnace protect the device from overheating in cases of changes in gas pressure or water flow. They also turn the fan on and off.

Before you buy a monostat for a boiler, you should find out the parameters of the spare part. Do the characteristics of the unit correspond to the specific model of the unit. The price of a DRD pressure switch depends on the model of the measuring device. Pressure is measured in bar, so the unit must be calibrated accordingly.

is one of the leading manufacturers of products for industrial automation in Russian cities: Moscow, St. Petersburg, Novosibirsk, Yekaterinburg, Nizhny Novgorod, Kazan, Chelyabinsk, Omsk, Samara, Rostov-on-Don, Ufa, Krasnoyarsk, Perm, Voronezh, Volgograd , Krasnodar, Ryazan.

Types of water flow switch

The most common water flow switch configuration for a pump is a petal switch. The classic circuit of the device consists of the following elements:

• inlet pipe;
• valve (petal) located on the wall of the inner chamber;
• isolated switch;
• springs of a certain diameter.

The reed switch opens and closes the power supply circuits that activate the compression spring. The principle of operation of the sensor in a water flow: when the chamber is filled with liquid, the flow forcefully displaces the valve from its axis, affecting the magnet, which operates the switch. The contacts close and the pump turns on.

There are several types of sensors with their own operating characteristics and application possibilities.

Mechanical paddles

The device is a device equipped with a blade that is built into the pipeline. The principle of operation is standard: when a flow enters, the blade deflects and acts on a magnet. The contacts close, the switch sensor is activated. The simplicity of the unit explains the wide range of applications. In addition, such sensors are practically not subject to wear and do not require maintenance - there is nothing to break in them.

Mechanical piston

The device operates on the basis of a magnetic piston system. Operating principle: when a flow enters, the piston with a magnet rises, closing the contacts - the relay is triggered to start. Without flow, the piston drops to its original position, preventing dry running. The main advantage of the device is the variety of designs that allow the device to be mounted in any position. Mechanical piston relays are used in high pressure systems.

Thermal

The device is equipped with a meter for the level of thermal energy dissipation from the built-in heating element. Depending on the change in the heating rate of the liquid, the flow itself and its flow rate are recorded. The thermal sensor is used only for safe types of liquid. Due to the use of the hot-wire principle, it is prohibited to use the relay to measure flammable substances, as well as liquids that change composition when heated.

Ultrasonic

The universal pulse water flow sensor operates on the principle of the acoustic effect. The device transmits an ultrasonic pulse through the flow, determining the liquid level. The most common are products whose functionality uses the movement of vibrations of a moving fluid. The devices are suitable for any substances, including flammable ones, and are easy to install and maintain.