First, let's look at why you need to install a water pressure switch for well pump. In another way, such a relay is also called a water pressure sensor in the water supply system. The pressure switch is small device, which measures the water pressure in the system and, depending on the obtained values, turns the pump on or off.
Pressure switch ACR РМ/5 represents simple design consisting of: a base, two adjustment springs, below we will look at what they are for and how to adjust, a group of contacts and a protective cover.
The operating principle of the pressure switch is as follows: we set the required on and off pressure. When the water pressure in the system decreases to the pressure set on the relay, at this moment the relay contacts close and the pump starts working, thereby pumping water into the accumulator, the pressure in the system increases to the level set on the relay, at which the relay opens the contacts and de-energizes our pump.
How to connect a pressure switch to a water supply system
Connection deep well pump to the pressure switch is carried out anywhere in the water supply system, but as a rule, all automation is mounted next to the hydraulic accumulator, so as not to pull long wires.
To connect the pressure switch, a special tee is used, which has three fittings: for water supply, a fitting for the pressure switch and a third for water drainage.
Relay connection diagram
The electrical circuit for connecting the pressure switch was discussed earlier in the article about the dry-running relay, so go to to study it in detail.
How to set up a pressure switch for a pump
Now let's talk about how to adjust the pressure switch. Let's look at the example of a Chinese relay ACR RM/5. As mentioned above, the relay has two adjustment springs. The large spring is designed to adjust the pump shut-off pressure, i.e., the more the spring compresses, thereby increasing the shut-off pressure, see the example in the figure
And vice versa, by releasing the spring we reduce the pressure at which the relay contacts open.
A small spring is designed to adjust the pressure range at which the pump will turn on and off, i.e. When the spring is compressed or decompressed, we reduce the difference between the cut-out pressure and the cut-in pressure.
For example, we had a pump shut-off pressure of 3 bar, a turn-on pressure of 1 bar, when we compress the spring, we reduce the pressure difference, thereby increasing the pump turn-on pressure to 2 bar.
With these simple manipulations, with adjusting springs, the pressure switch is adjusted and we achieve the pressure values we need at which our pump is turned off or on.
Types of pressure switches, advantages and disadvantages.
On Russian market There are two types of relays:
- mechanical
- electronic
Mechanical pressure switches wateris the most simple device automation. Its main advantage is its low cost, the cost ranges from 300 to 3500 rubles, plus it is very easy to install.
Unfortunately, it has a number of disadvantages:
- there is no overload protection - i.e. if we have a water blockage between the pump and the pressure switch, for example freezing in a pipe, then the pump will work until it burns out;
- lack of soft start - the pump starts immediately full power, thereby reducing the time between failures of the pump;
- cannot be used without a hydraulic accumulator - if the system is faulty or missing, and due to the fact that the pump starts at full power, the pipes in the water supply system shudder and this can lead to a rupture of the system with all the sad consequences of flooding the room.
Electronic water pressure switchfor a pump, compared to a mechanical one, it has finer settings for the water pressure in the system. As a rule, a flow sensor is also built into such a relay, which protects the pump from “dry running” and thereby eliminates the need for installation.
Electronic water pressure switch for pump
Pressure switch overview
The cheapest relay presented on the Russian market is a Chinese-made relayACR RM/5. It is not protected from dust and water and has two groups of contacts.
The German relay, under the brand name Condor MDR5/8, has proven itself very well. It has a dust and waterproof housing, gold-plated contacts, a two-pole contact group, i.e. both phase and zero are opened. Very easy adjustment, effortless. It has two groups of contacts: normally closed and normally open, therefore it can be used both as a pressure switch and as a dry-running protection relay. There is a hole on the body for installing a pressure gauge.
Another high-quality relay Tival FF4-8 (Grundfos), manufactured in Germany, has an index of protection against external environment IP52. It has a high-quality case and a tight cable outlet. A positive aspect of this relay is that it can be adjusted without a pressure gauge; inside the relay there is a graduated pressure scale and a pressure delta scale.
The disadvantages include the single-pole contact group, which only opens the phase.
Another representative of a high-quality relay is the Danfoss KPI relay, manufactured in Denmark. It has gold-plated contacts, which prevents the contacts from burning. Just like the previous relay, it can be adjusted without a pressure gauge on a scale. Can serve as a dry running relay.
Of the minuses - single-pole.
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Long gone are the days when the process of obtaining water for your home consisted of connecting a plug to an outlet. There followed a pause of 20-30 seconds, during which the electric pump had to turn on and pump liquid into the pipes, and only after that the stream filled the volume of the storage, pre-prepared container. A modern pumping station operates silently, and water is supplied to consumers instantly. Due to the inconvenience of use, above-ground wells are becoming a thing of the past. To use the water supply system, automation has long been used to turn on the pump.
Its main component is a pressure switch for the pump. Its purpose is to promptly turn on and off the power supply to the well pump that pumps water.
Installation individual systems There are many specialized organizations involved in water supply. They also carry out adjustments to the pumping station.
Installing a pumping station with your own hands can be done by a person who has studied the principles of water supply country house and settings of the water pressure switch for the pump, having the skills to use a screwdriver and wrenches.
Components of a water supply system
- Pipes;
- Pressure gauge. It is a mandatory device when adjusting the pressure switch of a pumping station;
- Relay with sensor;
- Dry running sensor. Used to turn off the power supply when there is no liquid supply;
- Filter fine cleaning. Responsible for cleaning from various impurities that are in the supplied water (sand, heavy metals, chlorine);
- Filter rough cleaning. Serves to clean fluid coming from a well from large particles of sand, earth, and rust;
- Ground level;
- Storage tank;
- Check valve. Permits liquid in one direction: from the pump to the house. Prevents water from draining through the pump into the ground and re-injecting it every time the pump is turned on;
- Borehole pump;
- Dump valve.
Important! Successful adjustment of the pumping station pressure switch is impossible if there is no hydraulic accumulator in the design of the water supply system.
Operating principle of a hydraulic accumulator
Purpose of the hydraulic accumulator:
- dampens pressure surges in the system during transition states in pump operation due to the elasticity of the membrane;
- reduces the frequency of pump starts;
- creates a supply of water in case of emergency situations.
It consists of a metal body, inside of which there is an elastic membrane that communicates with the water supply system through a fitting. Air is pumped through the spool.
The operating principle of the regulator is based on the laws of physics. Compression of liquids in normal conditions impossible. The air that fills the second chamber of the device, on the contrary, is easily compressed. Before water is pumped in, pressure is created through the spool hole expansion tank 1.3-1.9 Atm.
When the power supply is turned on, liquid from the well, entering the hydraulic tank, fills the space limited by the membrane, which, expanding, increases the air pressure in the hydraulic accumulator. A backwater of liquid is created throughout the entire water supply system. The shutdown threshold sets the water pressure switch for the pump. When the set level is reached, the device turns off. When you open the tap, the water is under the influence compressed air flows into the water tap. The pressure in the accumulator is reduced to a predetermined level, power is supplied to the pump, and it starts. The process is repeated. There are hydraulic accumulators with a large capacity (up to 100 l), which will allow you to do without the electricity necessary for the operation of the system for some time.
Types of automation
There are three generations of equipment automatic control liquid pressure.
The first generation is represented by mechanical devices. All structural elements of the device are assembled in a single housing. They are reliable and easy to set up.
The price of the relay is significantly lower than second and third generation devices. Installation is carried out through a fitting directly into the water supply system. Such equipment is adjusted according to the readings of the connected pressure gauge.
The second generation is represented by electronic relays. The signal is supplied by the water sensor. Such devices may have a mechanical or electronic group of contacts. The water pressure sensor can be installed separately from the relay. Many models have a small (up to 0.5 l) expansion tank, which allows you to do without a hydraulic accumulator. Pressure adjustment is carried out automatically according to preset parameters. This, however, is also the disadvantage of such systems. In case of accidents on the power supply line, users are left without a minimum supply of water. On the other side, electronic relay water pressure for the pump can provide more accurate settings for the required parameters for turning on and off the equipment. You can check the pressure using a pressure gauge.
The difference between the third generation and the second is that the pump is controlled electronic circuit, which allows you to smoothly change its operating modes and, accordingly, the pressure of the supplied water. Such devices place increased demands on the parameters of the power supply network. Their operation is not recommended without installing additional voltage stabilizers.
The price of third-generation control devices is several times higher than the cost of first-generation devices.
Correct operation of the hydraulic accumulator is impossible without a pumping station relay.
Pressure switch device
- Pump connection terminals;
- Network connection terminals;
- Nut and spring that establish the pressure difference;
- Fluid pressure adjustment nut;
- Rod spring;
- Ground connection terminals;
- Input for electrical wires;
- Connection fitting.
Specifications
Industrially produced devices are already configured according to existing standards and often do not require additional intervention. Equipment adjusted at the factory is most often capable of maintaining the pressure in the system within the range of 1.4-2.8 bar. At the same time, it allows you to produce manual setting in the range from 1.0 to 5.0 bar, which is enough to control deep-well pumps.
Attention! Changing the factory settings to the lower limit may lead to an increased frequency of pump activation. As a result, premature wear of the elastic membrane and pump. Significantly exceeding the upper cut-off limit above 2.8 bar can lead to destruction components plumbing (taps, mixers, washing machine and dishwasher valves).
Most models are designed to switch a voltage of 200 V at a current of up to 12 A. If the pump power is more than 2.5 kW, it is necessary to use power relays, which will be controlled by a pressure switch.
The water temperature in the pumping station should be between +5 and + 35 ºС. More low temperature water will lead to incorrect operation, high water increases the likelihood of destruction of the membrane, which transmits force to the rod of the activation mechanism.
Models are available in different climatic version, usually operating temperature indoors should not exceed + 45 ºС.
Operating principle of a pressure switch
The relay includes several components:
- membranes;
- rod;
- working springs;
- adjustment mechanism;
- groups of electrical contacts.
The pressure of the water entering the receiving fitting acts on the rod, which is under the action of the working spring. If the set pressure level in the system is exceeded, the working stroke becomes sufficient to break the contacts, which leads to the shutdown of the electric pump. A drop in pressure causes the rod to return to its original state and the water supply to turn on.
The upper and lower actuation limits are determined by the stiffness of the operating springs, which is determined by how many turns the adjusting nut is tightened on the rod.
The design has two rods. Larger installs working pressure, at which the pump will turn off. The shorter rod regulates the difference between the pressure that turns the pump on and off.
How the scheme works electrical connections can be understood from the figure below.
Installation of the device
If the factory settings no longer provide the correct operating modes of the pump, the device needs to be replaced; installing and adjusting the water pressure switch for the pump can easily be done on your own. To connect the relay, you will need a wrench, an adjustable wrench, and a screwdriver.
How to properly connect the pressure switch to the pump:
- It is best to install the device on the tank of the pumping station. For these purposes, adapters of suitable size are used. The proximity of the installation is due to the fact that this is where the most significant pressure surges occur;
- The climatic design of the device must correspond to the operating conditions;
- A check valve and a coarse filter must be installed in front of the relay. This arrangement will prevent dirt and rust particles from getting under the membrane, leading to damage. correct settings. Presence in the area between the pump and the accumulator check valve will prevent the pumped water from falling back into the well, reducing the pressure in the receiver. The pump will continually cycle on and off;
- The current strength that the relay is capable of switching must be sufficient to connect the pump. In cases where the pump has an operating current greater than that declared by the manufacturer, power relays should be additionally installed.
The figure also shows a dry-running sensor. It is triggered when there is loss of water in the well or other malfunctions when the pump stops working. The liquid pumped by the pump serves to lubricate and cool it. If it is missing, the pump will quickly fail.
Setting up a pumping station
The pressure switch can be adjusted at the connected pumping station.
Before pumping the system with water, use air pump it is necessary to pump in air, creating pressure in the hydraulic tank. For this purpose, use the spool hole, having previously freed it from the protective cap.
The operation of the pressure switch is not affected by the pressure created in the air chamber. The reduced pressure level causes constant stretching of the membrane. The pump will be connected after each use of the tap. Its excessive level in the chamber leads to the fact that when the tank is pumped, there will be a small volume of water in it, which also leads to an increase in the switching frequency. The norm is for the pump activation pressure to exceed this indicator in the air chamber by 10%.
Turn on the power supply to the system. Water should fill the hydraulic tank and turn off the pump. After this, open the protective cover and make final adjustments to the system.
How to set up a pressure switch to turn on the RDM-5 pump
This procedure does not require any additional accessories. The water pressure at which the pump turns on is adjusted according to the following algorithm:
- It is necessary to completely loosen the small spring adjustment nut;
- By compressing the large spring by rotating the nut clockwise, you can increase the pressure; accordingly, the tension is reduced in cases where the electric pump does not turn on;
- If switching occurs when high blood pressure, weaken the spring;
- Opening water tap, set the moment when the pump is turned on. The water pressure should be between 1.5-1.8 bar;
- By setting up the device, you ensure that the pump turns on during prolonged use of any source of water.
How to adjust the pressure to turn off
For this purpose, the pressure regulator is adjusted and a smaller adjusting spring is used for this.
By tightening the nut on a smaller rod, the pressure difference at which the pump turns on and off increases. If the nut is loosened, the pump shut-off pressure will decrease.
Important! Control of adjustments must be checked with the data measured by the pressure gauge; they must coincide with the recommended values. Reduced readings will lead to frequent switching on of the pump; reduced readings threaten the destruction of the components of the water supply system.
If adjustment cannot be made on our own, it is strongly recommended to contact a specialized organization. This will help avoid the costs of troubleshooting possible faults.
Video
Imagine that to get water at your dacha you can simply open the tap. That there is no need to fill containers with buckets for basic hygiene procedures, cooking, and cleaning. To do this you just need to install pumping equipment with a pressure sensor, but first you should understand its structure, don’t you agree?
Our article will introduce you in fine detail to the pressure switch for the pumping station. You will learn how the device works, how it activates and stops pumping. We describe in detail the popular options for pressure sensors and how to adjust them.
The device, small in size, belongs to the group of automation systems servicing pumping equipment. Its functionality is only possible in conjunction with a hydraulic accumulator. Despite its small size, the relay performs a number of important functions:
- allows all devices to function in the specified mode;
- Reacts sensitively to changes in on/off thresholds;
- activates and stops the pump when critical values are reached.
Simply put, it regulates the automatic process of pumping water in independent water supply schemes with membrane tank. Adjustment is made during commutation electrical circuits when the system reaches two pressure parameters accepted as the upper and lower limits.
When purchasing a pumping station, you receive a set of equipment, part of which is a pressure switch. Externally models different brands and series are similar, but may differ in shape, size, body color, setting method and location. At self-assembly automation, it is necessary to study the characteristics of the devices and select the most suitable ones for a particular system.
Layout of devices involved in organizing water supply to a private house from a well or borehole. The relay controls the operating pressure in the network, and the pressure gauge displays the current parameters
The devices are adapted for convenient installation and maintenance of the pumping station. Most often they are secured with a fitting at the inlet of the hydraulic accumulator, but they can also be mounted in a pipe HVS systems in close proximity to the device.
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Design and principle of operation
The pressure control relay has a simple dismountable design, thanks to which the user can independently adjust the operation of the accumulator, narrow or expand the parameters.
The internal parts are housed in a durable plastic case that resembles a box irregular shape. She has smooth surface and only 3 external working elements: two coupling clamps for electrical cables coming from the network and the pump, and a metal pipe ¼, ½, 1 inch for connecting to the system. The thread on the pipe can be either external or internal.
To remove the device body, you need to arm yourself with a flat screwdriver and slowly and carefully unscrew the screw recessed into the plastic, located above the axis of the large spring
Inside there is a base to which the working elements are attached: large and small springs with adjusting nuts, contacts for connection, a membrane and a plate that changes its position depending on the increase/decrease in pressure parameters in the system.
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The contacts of two electrical circuits, closed when the maximum pressure parameters are reached, are located under the springs, which are fixed to a metal plate. When the pressure increases, the membrane of the hydraulic tank is deformed, the pressure inside the bulb increases, and the mass of water presses on the plate. That, in turn, begins to act on the large spring.
When compressed, the spring is activated and opens the contact that supplies voltage to the motor. As a result, the pumping station is switched off. With a decrease in pressure (usually in the range of 1.4 - 1.6 bar), the plate returns to its original position and the contacts close again - the motor begins to work and pump water.
When purchasing a new pumping station, it is recommended to test the equipment to ensure that all components are working properly. Examination performance qualities the relay occurs in the sequence outlined below. As an example, the Haitun PC-19 model.
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Dry running alarm
Mechanical models do not have an indication or control panel, but they can be equipped with a forced activation button. It is necessary to make the device function.
Criteria for selecting a relay for a pump
There are many universal models, which are sold separately from pumping stations and can be used to assemble the system yourself. When purchasing a relay or automation unit, you must rely on the characteristics of the device. They can be found in technical documentation. It is important that the relay’s capabilities match the characteristics of the rest of the equipment.
Before purchasing an automation unit or relay, carefully study the technical data of the model. In most cases they are standard: nominal pressure from 1.5 atm., maximum – 3 atm.
You should start from the nominal pressure, but the upper limit of the operating pressure is also important. It is necessary to take into account electrical indicators and maximum temperature water. A mandatory parameter is the IP class, which indicates dust and moisture protection: the higher the value, the better.
Connecting thread sizes are indicated in inches: for example, ¼ inch or 1 inch. They must match the dimensions of the connection fitting. The dimensions and weight of the devices themselves are approximately the same and are secondary characteristics.
It should also be remembered that there are built-in and remote models. Most commercially available devices are universal: they can be connected directly to the hydraulic tank or mounted on a pipe.
Electronic relays have the same functions as mechanical ones: they are responsible for the water supply and protect the pump mechanism from dry running. They are more capricious than simple models, and are sensitive to suspended particles in water. To protect the device, a mesh dirt filter is installed in front of its connection point.
Essentially electronic device is an automation unit with a convenient display and a system of buttons that makes it possible to make adjustments without disassembling the device
One of the differences from traditional model consists of delaying pump shutdown. If, when the pressure increases, the mechanical device responds quickly, the electronic analogue turns off the equipment only after 10-15 seconds. This is explained by a careful attitude towards equipment: the less often the pump is turned on/off, the longer it will last.
Some switch models, as well as automation units, operate without a hydraulic accumulator, but their functionality is more limited easy to use. Suppose they are great for watering the garden or pumping liquid from one reservoir to another, but are not used in the home water supply system.
At the same time technical specifications devices are the same as traditional relays: factory setting 1.5 atm., shutdown threshold – 3 atm., maximum value – 10 atm.
Reasons for customization
The dismountable design of the device and the setup instructions were not invented in vain. Factory parameters rarely meet the requirements of the water supply system, as well as the volume of the accumulator.
Before the relay correction procedure, you must make sure that the hydraulic accumulator is in good working order and that the water supply system to the house is functioning properly, otherwise you may set the operating parameters incorrectly
Using the settings, you can not only “adjust” the upper and lower limits to optimal values, but also to make the operation of the equipment more gentle - for example, reduce the number of pump starts/stops. To do this, it is enough to slightly increase the range between operating pressures - delta.
You may also encounter incorrect settings of the factory model. If the delta is incorrectly coordinated and made too small, the pump will constantly turn on and off, reacting to a minimal increase in parameters.
By manipulating the springs, you can change the pump shutdown threshold, as well as adjust the volume of water in the accumulator tank. It is generally accepted that the larger the delta, the larger the volume of liquid in the tank. For example, with a delta of 2 atm. the tank is 50% filled with water, with a delta of 1 atm. – by 25%.
To achieve a delta of 2 atm, you need to set the lower pressure value, for example, to 1.8 atm, and the upper one to 3.8 atm, changing the position of the small and large springs
First let's remember general rules adjustments:
- to increase the upper response limit, that is, increase the shutdown pressure, tighten the nut on the large spring; to reduce the “ceiling” - weaken it;
- to increase the difference between the two pressure indicators, tighten the nut on the small spring; to reduce the delta, loosen it;
- moving the nut clockwise means increasing the parameters, counter-clockwise means decreasing them;
- To set up, you need to connect a pressure gauge, which shows the initial and changed parameters;
- Before starting the adjustment, you need to clean the filters, fill the tank with water and make sure that all pumping equipment is working.
All adjustment actions are carried out only after testing the system and detecting low performance or obvious errors in operation. It also happens that the station stops working due to a blockage that has clogged the filter or one of the narrow pipes.
Practical examples of relay configuration
Let's look at cases when turning to adjusting the pressure switch is really necessary. This usually happens when purchasing a new device or when frequent pump shutdowns occur. You will also need to configure it if you received a used device with lost parameters.
Connecting a new device
At this stage, you should check whether the factory settings are correct and, if necessary, make some changes to the operation of the pump.
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The pump stopped turning off
In this case, we forcibly turn off the pumping equipment and act in the following order:
- We turn it on and wait until the pressure reaches its maximum level - let's say 3.7 atm.
- We turn off the equipment and lower the pressure by draining water - for example, to 3.1 atm.
- Lightly tighten the nut on the small spring, increasing the differential value.
- We check how the cut-off pressure has changed and test the system.
- Setting it up best option by tightening and loosening the nuts on both springs.
If the reason was due to incorrect initial settings, it can be solved without buying a new relay. It is recommended to regularly, once every 1-2 months, check the operation of the pressure switch and, if necessary, adjust the on/off limits.
Situations that do not require adjustment
There can be many reasons when the pump does not turn off or turn on - from a blockage in the communications to engine failure. Therefore, before you start disassembling the relay, you should make sure that the rest of the pumping station equipment is working properly.
If everything is fine with the other devices, the problem is in the automation. Let's move on to inspecting the pressure switch. We disconnect it from the fitting and wires, remove the cover and check two critical points: the thin pipe connecting to the system and the contact block.
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If cleaning measures did not help, and adjusting the position of the springs was also in vain, most likely the relay is no longer suitable for further use and should be replaced with a new one.
Suppose you come across an old but working device. Its adjustment occurs in the same order as setting up a new relay. Before starting work, make sure that the device is intact, disassemble it and check that all contacts and springs are in place.
Conclusions and useful video on the topic
Practical video tips will help you better understand how to adjust a new pressure switch at a pumping station if the parameters do not suit you for some reason. You will also learn how the dry running device differs.
Professional tips for proper adjustment:
Comparative characteristics of two types of relays:
Specialists are usually not invited to correct the operation of the pressure switch, since this is a simple procedure that takes little time. You can leave the factory settings, but even minimal adjustments will help extend the life of the pump and hydraulic tank, and also optimize the operation of the station.
Automatic operation of the pumping station is impossible without the use of a water pressure switch for the pump. This device sets boundaries permissible value pressure in the system and pressure used by the consumer. As a result, the outlet always has stabilized water pressure, and the pump only works when there is a need for water.
Pressure switches can be mechanical or electronic. It was precisely mechanical devices due to its simplicity, reliability and reliability. Their setup requires minimal effort and can be done at the connection site.
The main task of the pressure switch is to control the pump. The pump supply line is switched through it. Switching on and off is carried out depending on the pressure in the pipes. For an automatic pumping station consisting of a pump and a storage tank, the working process occurs as follows:
- The nominal pressure of the system is established, as well as the permissible limits of the minimum and maximum pressure.
- When the minimum threshold is exceeded, the pump turns on and pumps water to the consumer and into the storage tank.
- If the upper set threshold is exceeded, the pump turns off.
The pressure switch determines the permissible limits of minimum and maximum pressure and turns on the pump according to the above algorithm.
Based on the method of controlling the pump, a distinction is made between power and signal relays. The first directly controls the power supply to the pump, and when choosing, you should focus on the maximum permissible current. The second, signal, switches or generates a low-voltage signal for the control unit.
The device is structurally divided into three parts:
- hydraulic block, membrane;
- detection unit, spring block trigger settings;
- power or signal relay.
The hydraulic unit of a simple mechanical pressure switch is a sealed chamber with a membrane inside. On one side of the camera there is a fitting for connecting to water pipe. Water enters one part of the chamber and presses on the membrane; on the other side, a movable rod is connected to it, coming out from the other side of the chamber.
The detection unit determines the conditions for operation of the relay and responds to changes in pressure in the system. A lever plate is connected to the rod coming out of the sensor chamber to control the power relay. Depending on the pressure applied to the membrane, the relay closes or opens the contacts. To balance the membrane and determine the maximum permissible response level, a spring block is attached to the rod, exerting pressure on it comparable to the effect of water pressure. The spring tension is adjusted using nuts and washers.
A power or signal relay is a group of detachable contacts and terminal blocks for connecting the power line going to the pump or signal line for the control unit.
Relay device diagram The key element of the device is the spring control unit. If you open any mechanical relay, you will find one large spring and one small one. They are the ones who determine the trigger levels.
A large spring exerts the main pressure on the sensor rod, determining the maximum permissible division, when increased, the relay contacts open and the pump turns off.
The smaller spring determines the pressure differential, the difference between the upper and lower response thresholds.
Both springs have adjusting nuts that control the degree of tension. It is important to correctly understand the purpose of springs.
If you change the degree of compression of a large spring, then both relay thresholds will simultaneously shift to one side or the other.
If you act on the smaller spring and leave the larger one alone, only the lower response threshold changes.
Connection diagram
The pressure switch is turned on after the pump and immediately before entering the storage tank. To protect the sensor from contamination and the effects of pressure surges as a result of starting and stopping the pump, the following must already be installed in front of it:
- coarse filter;
- pump;
- shut-off valve;
- check valve;
- fine filter;
- discharge to the sewer through a breakdown valve.
Relay connection diagram for pumping station For normal functioning In an automatic pumping station, the storage tank is adjusted to a maximum pressure higher than the required nominal pressure for water supply by approximately 0.5-1 bar. The upper threshold for relay operation is set at 0.2-0.3 bar below the maximum. The differential sets the width of the permissible pressure band and can correspond to a value of up to 2 bar.
The smaller the differential, the difference between the upper and lower response thresholds, the more often the pump turns on, but the more stable the pressure on the consumer side.
The higher the differential, the less often the pump turns on, but significant changes in pressure from the consumer are possible.
Power wires from the relay are connected to the relay terminals. distribution panel and pump power cables in accordance with the manufacturer’s instructions, focusing on the signatures and color coding wires. If there is a terminal marked "ground" in mandatory The cable is connected from the common ground.
Adjustment
The relay does not even require additional settings. If you select a relay with a suitable maximum permissible response threshold, then the factory settings already have optimal values. For pumping stations designed to supply water to a private home, this most often turns off at 2.5 (3) bar and turns on at 1.5 (1.8) bar.
However, to specify specific settings when the factory settings are not suitable, it is necessary to perform the initial setup of the equipment. This requires the installation of a pressure gauge connected to the same five-pin fitting as the relay. It is assumed that the entire system is already assembled and ready for the first start; if necessary, water has already been drawn to the check valve, excluding idling pump, and the storage tank already has a minimum volume of water.
Before setting, you should select:
- maximum permissible pressure in the system;
- minimum pressure;
- pressure air chamber hydraulic accumulator with drained water.
Before adjusting, you must remove the cover from the sensor and prepare appropriately sized socket wrenches for the adjusting nuts.
The procedure is as follows:
- Turn on the pump to fill the tank.
- When the pressure gauge reading reaches the required maximum value, for example 3 atm, manually turn off the pump. If the relay operates prematurely, then turn the main spring nut clockwise one or two turns and repeat this step.
- When the pressure in the system is established at the maximum level, turn the main spring nut counterclockwise until the relay switches off. This will set the upper threshold.
- Open any tap in the house and wait until the pressure gauge reading reaches the required lower response threshold. It is set 10% more than the pressure of the accumulator air chamber.
- If the relay has already activated while draining the water, then turn the nut of the smaller spring counterclockwise; if the relay does not operate, then turn it clockwise until the relay clicks.
- Turn on the pump and check that the installation is correct upper threshold, if it is too high or too low, make final adjustment by tightening or loosening the nut half a turn according to point 3.
- Drain the water through the tap until the lower threshold is triggered and the pump turns on again. Check the required value and, if there are deviations, repeat the setting according to point 5.
Electronic relay
Along with mechanical pressure switches, electronic relays are also used. More often they represent a full-fledged pump control unit, including a soft start and protective operation device and, accordingly, setting the upper and lower response thresholds in operating mode.
For adjustment, adjusting bolts located on the device body are used. For convenience, markings and marks are often applied around the bolts for orientation to specified pressures.
Electronic relays do not provide any particular advantages, but they are smaller in size and do not emit extraneous sounds when activated, although this is not relevant when installed directly next to the pump.