How to adjust the pressure switch at the pumping station. How to properly adjust the water station

The pressure switch is a small but indispensable unit of a large and small pumping station. And if all its other elements just need to be connected correctly, then it will also have to be additionally configured. It is this device that is responsible for automating the pumping process. It turns on and off the equipment according to the pressure in the hydraulic tank.

Properly performed adjustment of the pressure switch for the pump is a guarantee of comfort and long service life of the equipment. About how it is performed, what actions need to be taken and what data to know for fine-tuning, we detail in the article. You will find out why and in what situations it is produced.

In addition to a step-by-step description of the adjustment procedure, we provide valuable recommendations provided by hydraulic engineers. To optimize perception, the text is supplemented with photo collections, diagrams, video guides.

Numerous varieties, which are equipped with almost all pumping stations, are arranged in approximately the same way.

Inside the plastic case there is a metal base on which the rest of the elements are fixed:

• membrane;
• piston;
• metal platform;
• electrical contact assembly.

On top, under the plastic cover, there are two springs - large and small. When the diaphragm is under pressure, it pushes the piston.

He, in turn, raises the platform, which acts on a large spring, compressing it. A large spring resists this pressure, limiting the movement of the piston.

The small distance that separates the large and small adjusting springs is enough to regulate the operation of a whole range of devices. The platform under pressure from the membrane gradually rises until its edge reaches the small spring. The pressure on the platform at this moment increases, as a result, its position changes.

Image gallery

Pumping stations are a great way to provide autonomous water supply. They quickly entered our existence and hold their positions well. Household pumping station provides
automatic maintenance of the required pressure in the water supply system by self-switching on and off as water is consumed. But malfunctions of these stations happen quite often. Some of the faults are related to the nature of the environment - water and electricity - fast corrosion of metal parts. Submersible pumps, electric boilers and other equipment are also susceptible to this disease. If the parts of the station are damaged by corrosion, then they only need to be changed and, if possible, eliminate the cause, for example, check the grounding of the pumping station. Consider typical malfunctions and methods for their elimination

In the beginning, consider the device and principle of operation of a household pumping station.

Symbols in fig. 1-pressure line support, 2-faucet, 3-check valve, 4-pressure switch, 5-water inlet (Silverjet does not have), 6-pressure line, 7-pump, 8-line filter, 9-suction line , 10-hydraulic storage tank, 11-water, 12-check valve with a mesh, 13-cover closing the nipple, 14-hole for draining water.

The surface centrifugal electric pump consists of from a single-phase asynchronous motor and pump part. The electric motor consists of a finned housing, a stator, a rotor, a capacitor box and a fan closed with a protective casing. To protect the motor from overheating, a thermal relay is built into its stator winding. The pump part consists of a housing, an impeller and a built-in ejector. Pump housing,
depending on the model of the pumping station, it is made of cast iron, glass-polypropylene or stainless steel. The hydraulic accumulator consists of a steel tank and a replaceable membrane made of food-grade ethylene-propylene
rubber. The hydraulic accumulator has a nipple for pumping air into it under excess pressure. The pressure gauge serves to visually control the pressure in the water supply system, and the pressure switch determines the upper and lower pressure levels, upon reaching which the pump turns off and on.
The connection of the pumping station with the power supply network is carried out by means of a cable with a plug having a grounding contact and a socket with a grounding contact. After installing and turning on the pumping station, water fills the accumulator and the plumbing system. When the water pressure in the system reaches the upper limit of the pressure switch setting, the electric pump turns off. When you open a water tap, at the first moment of time, water is consumed from the accumulator. As the water flows, the pressure in the system drops to the lower limit of the pressure switch setting, after which the electric pump is turned on again. Water enters the consumer and simultaneously fills the accumulator. When the water pressure reaches the upper limit of the pressure switch, the electric pump will turn off again. The cycles of turning the pump on and off are repeated as long as water is being parsed from the system.
For the correct pumping station operation it is necessary to use a non-return valve with a strainer for coarse water purification on the suction line.

Recommendations for the installation of a pumping station. On the suction line, use plastic pipes of a certain rigidity, metal pipes or hoses reinforced for negative pressure (not to be confused with reinforced for pressure) in order to prevent their vacuum compression during suction.
8.1.2. If plastic pipes or hoses are used, avoid bending or twisting.
8.1.3. Seal all pipe connections well (air leakage adversely affects the operation of the pumping station).
8.1.4. For convenience when servicing the pumping station, it is recommended to use quick couplings (for example,
"American").
8.1.5. The suction pipe must have a non-return valve with a mesh at the end (fig. pos.12) when sucking from a well, and also, if small mechanical particles can enter, a main filter in front of the pumping station (fig. pos.8).
8.1.6. The end of the suction pipe must be lowered into the water to a depth of more than 30 cm from the minimum water level. It is also necessary that the distance between the end of the suction pipe and the bottom of the tank is greater than 20 cm.
8.1.7. It is recommended to install a non-return valve (Fig. 1 pos. 3) on the outlet pipe from the pump to prevent water hammer at the moments of turning the pump on / off and a valve (Fig. 1 pos. 2), the setting of which is described in paragraph 12, b. For the Silverjet, provide for the possibility of filling the pump with water, since there is no filler hole.
8.1.8. Fix the pumping station in a fixed position.
8.1.9. Avoid too many bends and taps in the system.
8.1.10. When sucking from a depth of more than 4 meters or if there is a horizontal section longer than 4 meters, use pipes with a larger diameter to improve the performance of the pumping station.
8.1.11. Protect the pumping station from running without water. If there is a risk of running the pumping station without water, contact your dealers for advice.
8.1.12. Ensure that water is drained from all points of the system if it is possible to freeze it in winter. To do this, provide for the presence of drain taps, paying attention to check valves that may be in the system and prevent water from draining.

Fixing the pump
9.1. The pump must be installed on level ground, close to the water source.
9.2. In the room (pit) where the pumping station is located, ventilation must be provided to reduce humidity and air temperature (max. air temperature 40°C).
9.3. Locate the pumping station keeping a minimum distance of 20cm from the walls to allow access to the pumping station during maintenance.
9.4. Use pipes of the correct diameter.
9.5. Mark holes for fastening the pumping station on the surface on which it will be installed. Drill holes for mounting the pump.
9.6. Check that the pipes are not under mechanical stress (bending), then tighten the fastening screws.

Read more about the selection and installation of a pumping station for autonomous water supply to a summer house or a private house.

Pumping station device

The main causes of malfunctions and repair of the pumping station

1. Engine is not runningNo power supply, blown fuse, impeller jammed.

Check the electrical connection diagram of the pumping station. Clean the pump. Turn the fan impeller, if it does not spin, the engine is malfunctioning (jammed). Do not turn on the station until the cause is eliminated.

Check pressure switch contacts. Check capacitor.

Before proceeding with the repair of the pump, it is necessary to drain the remaining water from it and disconnect all connected devices: expansion tank, pressure switch, pressure gauge and others.

A diffuser and a guide are installed in the housing, interconnected.

If the cause of the malfunction of the hydrophore is the breakdown of these parts, then you just need to replace them with new ones and assemble the hydrophore in the reverse order.

If the cause is not in them, then it is necessary to look for a malfunction in another part of the pump.

The back of the pump consists of the electric motor itself, on the shaft of which the impeller is installed - the main mechanism that allows the pump to pump water. The engine is attached to the console, and a special ceramic seal prevents water from leaking through the shaft. After you remove the impeller, you will have access to the stuffing box.

2. The engine is running, the station does not pump water
There is no water in the station pump. Air has entered the suction pipe. The suction or delivery line is clogged. The station is running dry.

Check the position of the water level. Eliminate all leaks in the pipeline. Clean suction pipe. With a long horizontal pipeline, an air pocket may form in the middle of the pipe. It is necessary to fill the entire pipeline with water (possibly under pressure) to eliminate the air lock. To exclude this, the horizontal section of the pipe must always be with a slight slope towards the water intake. Eliminate the causes of dry running

3. insufficient water supply
Air is trapped (for example, the level in the well has fallen below the intake pipe), the pump or pipelines are clogged. Air in the suction pipe.

Clean pump and pipes. Eliminate leaks. Even a small air leak leads to the inoperability of the station.

It is possible that a crack appeared on the details of the inlet pipeline structure (corners, American) as a result of corrosion. Replace damaged fittings.

4. The station turns on and off too often
The expansion tank diaphragm is damaged. Lack of compressed air in the expansion tank or low pressure. The check valve is open due to blockage by a foreign object.

Replace membrane or expansion tank. Again, due to corrosion, cracks may appear in the tank body. Pump air into the expansion tank and check the pressure with a pressure gauge. Unblock check valve.

5. The station does not create a nominal pressure
Pressure switch set too low. Impeller or supply line blocked. Air entering the suction pipe.

Adjust pressure switch. How to adjust is described below. The inlet of the pressure switch may be clogged - clean it.
Switch off the power, dismantle and clean the pump or supply pipe. Check the tightness of the connections on the suction pipe. Check that there are no bends or
reverse corners.

6. The station works without shutting down
Pressure switch set too high.

Adjust pressure switch.

If you are interested in repairing a pump such as Baby, Aquarius, Brook, Neptune, Chestnut - a detailed description.

Pressure regulation

If the adjustment is incorrect, the pump will not turn on or will work without turning off. Therefore, without urgent need, you should not change the settings of the pressure switch. The case of "incorrect operation" of the pumping station due to self-incorrect adjustment of the pressure switch is not covered by the warranty! And also the product is removed from the warranty if the components of the pumping station are out of order due to incorrect self-adjustment of pressure. If it is necessary to change the pressure in the plumbing system, its limit levels can be changed by adjusting the pressure switch.

Before changing the switching pressure of the pumping station (lower value of the operating pressure), it is necessary to adjust the air pressure in the accumulator. Before this, it is necessary to disconnect the pumping station from the mains and drain all the water from the accumulator. The air pressure in the accumulator is adjusted through the nipple by an automobile pump with a pressure gauge or a compressor. The air pressure in the accumulator must correspond to 90%..100% of the required switching pressure of the pumping station.

The pressure switch of the pumping station is set to operate the system in the operating pressure range of 1.5 ... 3 atm. To change the pressure on or off the pumping station, remove the cover of the pressure switch by unscrewing the plastic screw and change the tightening force of the corresponding relay springs. Adjustment of the pump activation pressure (lower value of the working pressure) is carried out by turning the nut P. To increase the activation pressure, it must be turned clockwise, to decrease - counterclockwise. Adjustment of the range between the lower and upper values ​​of the working pressure is carried out by turning the nut ΔР. To expand this range, it must be turned clockwise, to narrow it - counterclockwise. Pressure control is carried out on the pressure gauge of the pumping station.
ATTENTION!
When adjusting the pressure switch, the upper value of the operating pressure of the system should not exceed 95% of the maximum possible pressure at the outlet of the pumping station specified in the technical specifications. IN
Otherwise, the electric pump will work without shutting down, which will lead to its early failure.

Also note that hydraulic accumulator pumping station requires periodic maintenance. The water always contains a small part of the dissolved air, and this air gradually reduces the useful volume of the pear (rubber membrane) in the accumulator. On large-capacity accumulators, as a rule, there are special valves for releasing this air, in small accumulators, which are usually equipped with household pumping stations, there are no such valves, and a simple operation must be performed every couple of months to remove air from the membrane.

1. It is necessary to de-energize the pump and drain all the water from the accumulator, it is best of course to provide a special faucet for this, well, or use the tap closest to the accumulator.

2. The procedure from paragraph 1 must be done 2-3 times in a row.

And please do not confuse the accumulator and the storage tank for water, these are different devices, the accumulator is designed to reduce the number of pump starts, and as a result, increase its service life, as well as to protect against water hammer, when the electricity is turned off, the accumulator will, of course, supply you with water, but I wouldn't count on much. In case of a power outage or breakdown of the water supply, a storage tank is needed.

The pressure switch is one of the important parts of the pumping station. It is responsible for the operation of the pump at certain pressure values. The relay needs to be adjusted periodically. To do this, you should know how it works, its principle of operation and technical characteristics.

Regardless of its small size, the relay significantly extends the life of the pump, and also ensures the high-quality operation of the pumping station.

Peculiarities

When buying a pumping station, many people want to immediately get acquainted with its device. Each element is important. Directly for turning off and on the pump when certain pressure values ​​\u200b\u200bin the hydraulic tank are reached, the pressure switch is responsible.

The pressure switch is an element that regulates the water supply in the system. Due to the relay, the entire pumping system is turned on and off. It is the relay that regulates the water pressure.

According to the principle of operation, relays are divided into electronic and mechanical. It is easier to use electronic relays in terms of operation, but the service life of mechanical relays is longer. Therefore, mechanical relays are in great demand.

Relays can be either initially built into the pumping station, or go separately. Thus, according to the characteristics, it is easy to select a relay for the efficient operation of the pumping system.

Water inevitably contains foreign particles, and they are the main reason for the failure of electronic relays. Therefore, it is better to use a special separate filter for water purification. The main advantage of using an electronic relay is that it prevents the pumping station from running idle. After turning off the water supply, the electronic device continues to work for some time. In addition, such relays are easier to configure and install.

Often, pressure sensors immediately have factory settings. As a rule, they are set to 1.5-1.8 atmospheres to turn on, and 2.5-3 atmospheres to turn off. The maximum allowable pressure value for the relay is 5 atmospheres. However, not every system can withstand it. If the pressure is too high, it can cause leaks, wear of the pump diaphragm and other malfunctions.

The initial adjustment is not always suitable for certain operating conditions of the station, and then you have to adjust the relay yourself. Of course, for proper adjustment, it is best to become more familiar with what this small device is and how it works.

Device principle

The most common mechanical pressure switch of a pumping station is a metal plate on which there is a contact group on top, two spring-loaded regulators and connection terminals. The membrane cover is installed on the bottom of the metal plate. It directly covers the membrane and the piston attached to it. And also on the cover there is a threaded connection for installation on the adapter, which is located on the pumping equipment. All of the above construction details are covered with a plastic cover.

On the working part of the regulator, this cover is fixed with screws.

It can be removed if necessary using a wrench or screwdriver.

Relays can have a different configuration, shape, and even differ in the location of some elements or the connection diagram. There are relays that have additional protective elements that keep the device dry when running and allow you to protect the motor from overheating.

For the water supply of a private house, station designs are used in which RM-5 or its foreign analogues act as a pressure regulator. Such a model of the pressure switch inside has a movable plate and two springs on its opposite sides. The plate is moved by the water pressure in the system using a membrane. By turning the clamping nut of one or another spring block, it is possible to change up or down the limits at which the relay operates. The springs, as it were, help to ensure that the water pressure displaces the plate.

The mechanism is made in such a way that when the plate is displaced, several groups of contacts open or close. If we consider the scheme of work, then it will be as follows. When turned on, the pump supplies water to the accumulator. Power is supplied to the motor through the closed relay contacts. This increases the water pressure in the tank.

When the pressure reaches the value set by the upper limit springs, the mechanism is activated, the contact opens, and the pump is turned off. The liquid from the pipeline does not flow back into the well due to the check valve. As the water is used, the pear becomes empty, the pressure drops, and then the lower parameter spring is activated, which closes the contacts, including the pump. Then the cycle repeats.

During the operation of the entire pumping station, the operation of the pressure switch is as follows:

• a tap with water opens, and it comes from a filled hydraulic tank;
• in the system, the pressure begins to decrease, and the membrane presses on the piston;
• contacts close and the pump turns on;
• water enters the consumer, and when the tap closes, it fills the hydraulic tank;
• when water is drawn into the hydraulic tank, pressure rises, it acts on the membrane, and it, in turn, on the piston, and the contacts open,
• the pump stops working.

The relay settings also determine how often the pump will turn on, the water pressure, and the service life of the entire system as a whole. If the parameters are set incorrectly, the pump will not work correctly.

Training

The relay should only be adjusted after checking the air pressure in the accumulator. To do this, you should better understand how this very hydraulic accumulator (hydraulic tank) works. It is a hermetically sealed container. The main working part of the container is a rubber pear into which water is drawn. The other part is the metal case of the accumulator. The space between the body and the pear is filled with pressurized air.

The pear in which water accumulates is connected to the water supply system. Due to the air in the hydraulic tank, the pear with water is compressed, which allows you to maintain the pressure in the system at a certain level. Thus, when a tap with water is opened, it moves through the pipeline under pressure, while the pump does not turn on.

Before checking the air pressure in the hydraulic tank, it is necessary to disconnect the pumping station from the network, and drain all the water from the hydraulic accumulator tank. Next, open the side cover on the tank, find the nipple and use a bicycle or car pump with a pressure gauge to measure the pressure. Well, if its value is about 1.5 atmospheres.

In the event that the result obtained is of a lower value, then the pressure is raised to the desired value using the same pump. It is worth recalling that the air in the tank must always be under pressure.

For a hydraulic tank with a volume of 20-25 liters, it is better to set the pressure in the range of 1.4-1.7 atmospheres, with a volume of 50-100 liters - 1.7-1.9 atmospheres.

When using a pumping station, it is important to periodically check the air pressure in the hydraulic tank.(about once a month or at least every three months), and if necessary, pump it up. These manipulations will allow the accumulator membrane to work longer. But also, the tank should not be empty for too long without water, as this can lead to drying out of the walls.

After adjusting the pressure in the accumulator, it happens that the pumping station stops working in normal mode. This means that the pressure switch should be adjusted directly.

How to set up with your own hands?

When starting the well pump and station, the relay setting is very important. And it must be done correctly.

Despite the fact that the pressure switch immediately already comes with factory settings, the best option would be to additionally check and adjust them. Before you start adjusting the relay, it is worth finding out what the values ​​recommended by the manufacturer are in order to set the allowable pressure values. However, it must be borne in mind that the failure of the pumping station due to incorrect settings is a non-warranty case.

When making calculations of the permissible values ​​​​of the pressure of operation and shutdown of automation, the manufacturer takes into account the possible features of operation. Moreover, this is done when developing parameters for the work.

When selecting them, the following data are taken into account:

• required pressure in the highest section of the water supply;
• the difference in height between the pump and the highest section of water extraction;
• possible pressure drop during water transfer.

Before adjusting, you need to prepare tools in the form of a set of screwdrivers and wrenches. Usually the relay cover is made black so that it does not merge with the entire accumulator. Under the cover are two springs that act as a regulator. Each spring has a nut.

It should be noted that the size of the upper spring is larger, and the nut on it regulates the shutdown pressure. It is also sometimes referred to as the letter "R". A small nut on the bottom spring allows you to adjust the pressure difference. The designation of a small nut is in the form of "ΔP" (delta P).

It is worth remembering that the accuracy of the settings made is best checked by the pressure gauge that is built into the system. To ensure more accurate settings, it is important to compare the obtained values ​​\u200b\u200bwith those indicated in the passport of the pumping station. Be careful not to exceed the maximum values.

To raise the pressure value at which the station will turn off, the “P” nut is tightened clockwise, and to decrease it, counterclockwise. Often, next to the nut, the designations in the form of "+" and "-" are affixed. The rotation of the nut must be carried out slowly, less than a turn at a time. It is useful to remember that with a larger value of "P" there will be more water in the pear, which means that the pump will turn on less often.

Before proceeding directly to setting up the relay, you should at least understand a little how the pumping station works as a whole. The hydraulic accumulator contains a rubber bulb and air. The pump pumps water from the well into the pear. It is filled with water, air is compressed, and pressure is created on the walls.

Adjusting the pressure switch allows you to independently set the tank filling limit, that is, the moment when the pump should turn off. The pressure in the system is displayed on the pressure gauge. It is worth noting that water will not flow into the well due to the check valve.

When the tap in the house opens, the water leaves the pear with a pressure equal to the set pressure. The water from the pear is consumed, and the pressure decreases, and when it reaches the lower threshold, the pump will turn on.

When assembling the pumping station, the pressure switch is connected between the outlet fitting of the hydraulic tank and the check valve on the pipeline. When assembling, it is best to use a five-point fitting, which has a thread for the main parts, including a pressure gauge. It is very important to install the check valve and fitting in the correct order. Otherwise, it will be difficult to adjust the pressure switch.

It is worth noting that, in addition to the relay, the pumping station may also include a “dry running” sensor, as well as a frequency converter, if necessary.

The air pressure in the hydraulic tank has been checked and has an optimal value, all filters in the system are new or replaced, which means that you can start setting up the pressure switch. First you need to turn off the pump, then drain the water from the pipeline by opening the lowest tap if possible. After, using a wrench or screwdriver, you need to remove the plastic case from the relay. Turn on the pump and let the system fill with water.

After the relay is activated and the pump is turned off, record the value displayed on the pressure gauge. It is this value that is the upper pressure limit. Next, you need to partially open the valve located at the highest possible section of the system. In the case of a single-level water extraction system, it is necessary to open the tap furthest from the pump.

When the pressure drops to a certain value, the pump will start. At this point, it is necessary to record the data using a pressure gauge. We get the value of the lower pressure. If we subtract it from the upper pressure recorded earlier, we will get the value of the current relay pressure difference.

However, in addition to the pressure value, it is necessary to check whether sufficient water pressure is created in the highest and most distant tap of the system. If it is weak, then it is necessary to increase the value of the lower pressure. First, the device is disconnected from the mains, and then the nut, which is located on the larger spring, is tightened. In case of strong pressure, the nut is loosened to reduce it.

Now you can adjust the relay pressure difference found above. Usually, 1.4 atmospheres is considered the optimal value. With less, the water supply will be more uniform, but the pump will turn on more often, which reduces the life of the system.

With a relay pressure difference of more than 1.4 atmospheres, the system will not operate in such a strong wear mode, but the difference between the highest and lowest pressure will become very noticeable. To adjust it, turn the nut on the smaller spring. To increase the differential pressure value, turn the nut clockwise. If the spring is loosened, the result will be the opposite.

With completely weakened springs, the relay is configured in a slightly different way. First, the pumping station is started to pressurize the system. It is produced to a level until water flows at an acceptable pressure from the tap farthest from the pump. For example, at the moment the pressure gauge showed 1.5 atmospheres. This pressure is fixed by disconnecting the pump and the pumping station from the power supply.

Then the plastic case is removed from the relay and the nut, which is located on the larger spring, is tightened to a characteristic click, which indicates that the contacts are triggered. Next, the relay housing is installed in place, and the pumping equipment is started. The pressure is increased by 1.4 atmospheres.

After that, the device is again disconnected from the power supply, the relay housing is removed and the nut of the smaller spring is tightened until it clicks. This is a contact opening click. We get a pressure switch configured to operate at an upper pressure of 2.9 atmospheres and a lower pressure of 1.5 atmospheres. After completing the settings, return the plastic case of the relay to its place and connect the pumping station to the mains.

The adjustment of the automation of the pumping station is initially performed by the manufacturer at a certain pressure value when the equipment is turned on and off. Typically these factory settings are between 1.5 and 1.8 bar when turned on and between 2.3 and 3 bar when turned off.
But there are situations when additional pressure adjustment on the equipment is necessary during operation. How to adjust the pumping station is invited to learn from this article.

The process of installing a pumping station: basic recommendations

In order to prevent vacuum compression of the pipes on the suction line, it is necessary that they have a certain rigidity, if they are plastic, they can also be metal, reinforced for vacuum.

Caution: It is very important that these pipes or hoses are not bent or kinked.

So:

• All connections must be highly sealed. Air that can be sucked in has a bad effect on the functioning of the station.
• It is very convenient to use quick couplings when servicing the station. An example of such a connection can be called "American".
• It is necessary that the suction pipe be equipped with a special non-return valve with a mesh. Also, a main filter can be used before the pumping station. This will protect the system from small particles entering it.
• One side of the suction pipe must sink into the water at least 30 cm below the water surface. It is also important that at least 20 cm remain to the bottom of the well.
• It is recommended to equip the outlet pipe of the pumping station with a check valve, which will protect it from water hammer when the pump is turned on and off.
• The pumping station must be fixed in a fixed position.
• It is better to refrain from a large number of taps and bends in the system.
• If the suction depth is more than 4 m or the system has a horizontal section that is more than 4 m long. it is better to use pipes with a larger diameter, as this will improve the performance of the station.
• It is necessary to secure the pumping station from operation in the absence of water. If there is such a risk, it is better to consult a specialist about the possibility of solving this problem.
• In order to prevent the system from freezing in winter, it is better to foresee the possibility of draining water at all points in the system. This can be done with the help of drain taps, while it is necessary to pay attention to the presence of check valves that will not allow the water to drain.

The process of fixing the pumping station

The pump must be installed on a level surface, preferably as close to a water source as possible:

• In the room where the pumping station is located, proper ventilation should be organized, which will reduce humidity, as well as the temperature regime of no more than 40 ° C.
• Between the pumping station and the walls of the room where it is located, there must be a distance of at least 20 cm, this allows you to have access to the system during its maintenance.
• The pipes used for fixing must have the appropriate diameter.
• Next, you need to outline the holes for fasteners on the surface where the station will be located, and then drill them.
• Before finally fixing all the screws on the fasteners, it is better to once again check if there are any bends on the pipes that give them mechanical stress.

Pressure switch device for a pumping station

Before you start adjusting the pressure switch, you need to familiarize yourself with its device and the principle of operation.

The photo shows the design of the device.
Its main elements:

• 1 and 2 are spring adjusters.
• 3 - the base of the device.
• 4 - a nut that fixes the relay to the adapter and the membrane cover.
• 5 - block with terminals for connecting the 220V network, the pump itself and its grounding.

A membrane cover is attached to the metal base from below, under which there is a membrane and a piston with a quick-release nut pos. 4. On top there is a contact group, terminal blocks and two spring adjusters of different sizes.
All elements are closed on top with a plastic cover attached to the screw of the large regulator and which, depending on the model, can be easily removed with a screwdriver or wrench.
Different models of products, the price of which does not fluctuate greatly, may differ in size, shape, arrangement of the constituent elements, but most of them have the above-described design. Some of the products include additional elements, such as a lever that includes protection against "dry running".

How a relay works

The relay works like this:

• Under the action of the pressure of the liquid supplied from the pump, the membrane begins to put pressure on the piston.
• It activates the contact group, which is mounted on a metal platform with two hinges.
• Contacts for connecting voltage 220V and the pump, depending on the position, can be open or closed, which corresponds to turning the pump off and on.
• When the contact group of the large regulator spring acts on the platform, the piston pressure is balanced.
• If the pressure begins to weaken, under the action of the spring, the platform begins to fall and the contacts close, which turns on the pump (see).
• The spring of the small regulator also acts against the water pressure, but it is located farther from the platform hinge and does not immediately enter into operation, but after the platform with the contacts can rise to a certain height.
• A small hinge with a spring is responsible for actuating the electrical section of the relay, for closing and opening its contacts.

• The design of the relay is designed so that the hinge and the platform cannot be located in the same plane.
• When the platform is raised above the hinge, the contacts jump down, and when lowered below its plane, the elements immediately snap upwards.
• The location of the plane of this hinge is slightly higher than the base of the spring of the small regulator, allows the platform to rise without opening the contacts to this level, and when it is reached, under the action of the springs of these two regulators, the contacts will open and the pump will turn off.
• At the same time, the large spring regulator is thus responsible for the moment the unit is turned on or for the “lower” pressure (P), and the smaller one is responsible for the difference in pressures off and on (∆P).
• When the spring of the large regulator is compressed, which is done by turning the nut clockwise, it acts with greater force on the platform of the contact group, which causes an increase in the “lower” pressure.
  If in this case you do not change the degree of compression of the spring of the smaller regulator, the "upper" pressure or shutdown will also increase, up to the same value. In this case, ∆P will remain unchanged.
• When the spring of the smaller regulator is compressed, the "upper" pressure will increase, while the "lower" pressure will not change, which will lead to an increase in ∆P.
• With a corresponding weakening of the springs, these figures will decrease.
• The adjustment of the pressure switch of pumping equipment is based on this principle.

How is the pressure switch regulated independently

Before adjusting the automation, it is necessary to prepare a screwdriver or a wrench to remove the relay cover and a wrench for tightening or unscrewing the nut adjusters.
After that, the manual for doing the work with your own hands is as follows:

• Disconnected from voltage by the pressure switch.
• The plastic cover of the relay is removed and it is adjusted depending on its purpose:

1. increase in pressure;
2. downgrade;
3. change in the range of operation of the equipment.

• Under the cover are mounted two spring regulators responsible for the lower and upper pressure.

To increase or decrease the pressure in the network, you must:

• Just screw or unscrew the nut on the larger regulator.
• After changing the setting, the lid closes.
• The voltage is turned on.
• The valve opens and the pressure gauge built into the pumping station determines the pressure at which the pump turns on or “lower”.
• The valve closes and the “upper” pressure is checked on the pressure gauge when the pump is turned off.

Tip: If the pressure is satisfactory, the adjustment is considered complete. If not, everything repeats again.

How to change the range of the relay

If the "lower" pressure is normal, but you only need to increase or decrease the "upper" pressure, you need to use a smaller regulator.
Wherein:

• Tightening the nut for this regulator clockwise will increase the "upper" pressure, while the "lower" pressure remains unchanged.
• Unscrewing is the opposite: in this case, the difference between them will decrease or increase - ∆P.
• After changing the adjustment, the power is turned on and the moment is noticed on the pressure gauge when the pump is turned off - the “upper” pressure.
• If the results are satisfactory, the adjustment can be stopped at this point, if not, the process is repeated until the desired result is obtained.

Tip: It must be borne in mind that an increase in ∆P allows the pump to turn on less often, but in this case more noticeable pressure drops will occur in the water supply network, and if it is reduced, on the contrary, it will equalize it in the system, but the pump will turn on more often, which will lead to to reduce its service life.

If both the “lower” pressure and the relay operation range are not satisfied at the same time, it is necessary to first adjust with a large regulator, and after that with a smaller one, the whole process is controlled by the station pressure gauge.

What is taken into account when making adjustments

When adjusting the operation of the equipment relay on your own, it is necessary to take into account such important points:

• It is impossible to set the "upper" pressure, which is more than 80% of the maximum for the product, on this model. As a rule, it is indicated on the packaging or in the instructions, and ranges from 5 to 5.5 bar.
  To set a higher level in the system of a private house, it is necessary to select a relay with a higher maximum pressure.
• Before increasing the pressure to turn on the pump, it is necessary to get acquainted with its characteristics, whether it can develop such pressure. Otherwise, if it cannot be created, the unit will not turn off, and the relay will not be able to turn it off, because the set limit cannot be reached.
  The pump head is measured in meters of water column: 1 m of water. Art. = 0.1 bar. In addition, hydraulic losses in the entire system are also taken into account.
• It is impossible to tighten the nuts of the regulators to failure during regulation, otherwise the relay may completely stop working.

Influence of air pressure in the tank

The normal operation of the equipment depends on the amount of air pressure in the accumulator (see) of the equipment, but it has nothing to do with the adjustment of the relay. In any case, it will start to work at a certain “lower” and “upper” pressure, regardless of its presence in the tank.
In the absence of air in the membrane tank, it can only lead to complete filling with water and the pressure in the system will begin to rise instantly to the “upper” one and the pump will immediately turn off after the fluid intake stops. Each time the tap is opened, the pump turns on, it will immediately fall to the "lower" limit.
In the absence of a hydraulic accumulator, the relay will still work. Reduced air pressure leads to a strong stretching of the membrane, and increased air pressure leads to insufficient filling of the tank with water. In this case, excess air pressure will displace the liquid.
For the normal operation of the pumping station and the long service life of the membrane, it is necessary that the air pressure be 10% less than the “lower” one set during the adjustment. Then the accumulator will be normally filled with water, and the membrane will not stretch too much, which means it will last for a long time. In this case, the pump will turn on at intervals corresponding to the ∆P adjusted in the relay.
In addition, it is necessary to check the air pressure in the tank of the pumping station in the absence of liquid pressure in it. In this case, you need to open the tap located in the system below everything and drain all the water.
The details of adjusting the pressure switch are well shown in the video in this article.

Tip: When setting up the pressure switch, you need to remember that the accumulator or tank, plumbing, all hoses and relay mechanics have their own pressure limits that cannot be exceeded.

To make an autonomous water supply system in a small private house, a conventional pump, borehole or surface, with suitable performance characteristics will be enough. But for a house in which more than 4 people live, or for a 2-3-storey dwelling, you will need to install a pumping station. This equipment already has factory pressure settings, but sometimes they need to be adjusted. When adjustment of the pumping station is required, and how to do it, will be described below.

In order to properly adjust this pumping equipment, you must have at least a minimal idea of ​​​​how it works and on what principle it works. The main purpose of pumping stations consisting of several modules is to provide drinking water to all water intake points in the house. Also, these units are able to automatically increase and maintain the pressure in the system at the required level.

Below is a diagram of a pumping station with a hydraulic accumulator.

The pumping station includes the following elements (see the figure above).

1. Hydraulic accumulator. It is made in the form of a sealed tank, inside of which there is an elastic membrane. In some containers, a rubber bulb is installed instead of a membrane. Thanks to the membrane (pear), the hydraulic tank is divided into 2 compartments: for air and for water. The latter is pumped into a pear or into a part of the tank intended for liquid. The accumulator is connected in the section between the pump and the pipe leading to the water intake points.
2. Pump. It can be surface or borehole. The pump type must be either centrifugal or vortex. The vibration pump for the station cannot be used.
3. Pressure switch. The pressure sensor automates the entire process by which water is supplied from the well to the expansion tank. The relay is responsible for turning the pump motor on and off when the required compression force is reached in the tank.
4. check valve. Prevents leakage of fluid from the accumulator when the pump is turned off.
5. Power supply. To connect the equipment to the electrical network, it is required to stretch a separate wiring with a cross section corresponding to the power of the unit. Also, a protection system in the form of automatic machines should be installed in the electrical circuit.

This equipment works according to the following principle. After opening the tap at the water intake point, water from the accumulator begins to flow into the system. At the same time, compression is reduced in the tank. When the compression force drops to the value set on the sensor, its contacts close and the pump motor starts to work. After the cessation of water consumption at the water intake point, or when the compression force in the accumulator rises to the required level, the relay is activated to turn off the pump.

The device and principle of operation of the pressure switch

The pressure switch device of the pumping station is not complicated. The design of the relay includes the following elements.

1. Housing (see picture below).

1. Flange for connecting the module to the system.
2. Nut designed to adjust the shutdown of the device.
3. A nut that regulates the compression force in the tank at which the unit will turn on.
4. Terminals to which the wires coming from the pump are connected.
5. Place for connecting wires from the mains.
6. Ground terminals.
7. Couplings for fixing electrical cables.

There is a metal cover on the bottom of the relay. If you open it, you can see diaphragm and piston.

The principle of operation of the pressure switch next. With an increase in the compression force in the hydraulic tank chamber designed for air, the relay membrane flexes and acts on the piston. It sets in motion and activates the contact group of the relay. The contact group, which has 2 hinges, depending on the position of the piston, either closes or opens the contacts through which the pump is powered. As a result, when the contacts are closed, the equipment is started, and when they are opened, the unit stops.

When to Adjust the Relay

As mentioned above, the relay automates the process of pumping fluid into the plumbing system and into the expansion tank. Most often, pumping equipment purchased ready-made already has basic relay settings. But there are situations when urgent adjustment of the pressure of the pumping station is required. You will need to perform these steps if:

• after starting the pump motor, it immediately turns off;
• after the station is turned off, there is a weak pressure in the system;
• during the operation of the station, an excessive compression force is created in the hydraulic tank, as evidenced by the readings of the pressure gauge, but the device does not turn off;
• the pressure switch does not work, and the pump does not turn on.

Most often, if the unit has the above symptoms, then relay repair is not required. You just need to properly configure this module.

Tank preparation and adjustment

Before the accumulators go on sale, air is pumped into them at a certain pressure at the factory. Air is pumped through the spool installed on this container.

On average, the pressure in the pumping station should be as follows: in hydraulic tanks up to 150 liters. - 1.5 bar, in expansion tanks from 200 to 500 l. - 2 bar.

Under what pressure is the air in the hydraulic tank, you can find out from the label glued to it. In the following figure, the red arrow indicates the line in which the air pressure in the accumulator is indicated.

Also, these measurements of the compression force in the tank can be made using car pressure gauge. The measuring device is connected to the spool of the tank.

To start adjusting the compression force in the hydraulic tank, you need to prepare it:

1. Disconnect the equipment from the mains.
2. Open any faucet installed in the system and wait until the liquid stops flowing from it. Of course, it will be better if the crane is located near the drive or on the same floor with it.
3. Next, measure the compression force in the container using a pressure gauge and note this value. For small volume drives, the indicator should be about 1.5 bar.

In order to properly adjust the accumulator, the rule should be taken into account: the pressure that triggers the relay to turn on the unit must exceed the compression force in the accumulator by 10%. For example, the pump relay turns on the motor at 1.6 bar. This means that it is necessary to create an appropriate air compression force in the drive, namely 1.4-1.5 bar. By the way, the coincidence with the factory settings is not accidental here.

If the sensor is configured to start the engine of the station with a compression force greater than 1.6 bar, then, accordingly, the settings of the drive change. You can increase the pressure in the latter, that is, pump air, if you use car tire pump.

Advice! Correction of the air compression force in the accumulator is recommended to be carried out at least once a year, since during the winter it can decrease by several tenths of a bar.

Setting the pressure switch

There are times when the default sensor settings do not suit users of pumping equipment. For example, if you open a tap on any floor of a building, you will notice that the water pressure in it is rapidly decreasing. Also, the installation of some water purification systems is not possible if the compression force in the system is less than 2.5 bar. If the station is set to turn on at 1.6-1.8 bar, then the filters will not work in this case.

Usually, setting up a pressure switch with your own hands is not difficult and is performed according to the following algorithm.

1. Write down the readings on the pressure gauge when turning the unit on and off.
2. Unplug the station's power cord from the socket or turn off the machines.
3. Remove the cover from the sensor. Usually it is fixed with 1 screw. Under the lid you can see 2 screws with springs. The one that is larger is responsible for the pressure at which the station engine starts. Usually, next to it there is a marking in the form of the letter “P” and arrows are drawn with the signs “+” and “-” applied next to them.
4. To increase grip strength, turn the nut towards the “+” sign. And vice versa, to reduce it, you need to turn the screw to the “-” sign. Turn the nut one turn in the desired direction and start the machine.
5. Wait until the station turns off. If the pressure gauge readings do not suit you, then continue to turn the nut and turn on the device until the pressure in the accumulator reaches the required value.
6. The next step should set the time to turn off the station. A smaller screw with a spring around is designed for this. Near it is the marking “ΔP”, as well as arrows with the signs “+” and “-”. Setting the pressure regulator to turn on the device is carried out in the same way as to turn off the device.

On average, the interval between the compression force at which the sensor turns on the engine of the station, and the value of the compression force when the unit stops, is in the range of 1-1.5 bar. In this case, the interval may increase if the shutdown occurs at large values.

For example, the unit is factory set to P on = 1.6 bar and P off = 2.6 bar. It follows from this that the difference does not go beyond the standard value and is equal to 1 bar. If for some reason it is required to increase P off to 4 bar, then the interval should also be increased to 1.5 bar. That is, P on should be about 2.5 bar.

But as this interval increases, so will differential pressure in the water supply system. Sometimes this can cause discomfort, since you have to use more water from the tank in order for the station to turn on. But due to the large interval between P on and P off, the pump will turn on less often, which will increase its resource.

The above-described manipulations with the compression force settings are only possible with equipment of the appropriate power. For example, in those the passport to the device states that it can give out no more than 3.5 bar. This means that it does not make sense to set P off = 4 bar on it, since the station will work without stopping, and the pressure in the tank will not be able to rise to the required value. Therefore, in order to obtain a pressure in the receiver of 4 bar and above, it is necessary to purchase a pump of the appropriate capacity.