Frequency converters for pumps: prices, specifications and reviews. Why do you need a frequency converter for a pump? Used water supply converters What you need to know when assembling the circuit and setting up the converter

Automation of pumping equipment can be considered the most important aspect in the field of technical development of water supply and sanitation systems. This is important not only for stations that provide water to settlements.

A smart pump for a well will also make the operation of an autonomous water supply system comfortable. To do this, it is very important to correctly calculate the borehole pump, and, accordingly, to select a frequency converter for it.

The video in this article will help you do it yourself.

Advantages of automatic water supply

In order to achieve the most gentle operation of the equipment, everything is automated at pumping stations - from starting and stopping the units, and ending with the control of water flow. Devices that help to exercise total control over the system transmit signals to the scoreboard in the control room.

Approximately the same, only on a smaller scale, occurs in the case of home pump automation. Let's look at the advantages that automation gives to the system.

So:

• The most important thing is that the smooth start and stop of the pump motor reduces the likelihood of water hammer to zero, and the careful operation mode helps to extend the life of any equipment. This reduces the costs associated with the operation of the water intake.
• First of all, it is the consumption of electricity. Its price is steadily growing, and everyone feels it: both individuals and enterprises. Frequency regulation of the operation of pump motors makes it possible to reduce the volume of storage tanks, and even completely abandon them.

In such cases, they use a device called: "inverter control unit for a borehole pump" - it is what you see in the photo above. The inverter combines various combinations control devices, which the pump itself is not equipped with, and, among other things, has a built-in frequency converter.

Functionality and selection of the frequency converter

It is clear that the maximum consumption of water occurs only at certain moments, and most time, the pump power is excessive. A frequency converter allows you to configure the system so that during the "rush hour" the pump gives out full power, and at other times it reduces speed.

• From the number of rotations in a certain period of time of the pump wheel, the pressure developed by it depends, and, accordingly, the performance. The essence of using a frequency converter is to make the motor shaft rotate at a given pace. At the same time, the frequency alternating current received from the mains, changes its value.
• Modern converters have the widest range, and are able to convert voltage both above and below the characteristics of the mains supply. The circuit of this device is divided into two parts: a power one, consisting of a group of transistors or thyristors, and a control one, in fact, an electronic key.
• The control part consists of digital microprocessors, and performs all control and protective functions. Since the structure of the power section has characteristic differences, frequency converters are divided into two groups. One of them includes devices with an intermediate DC link.

• The second group does not have this link, and is called "frequency converters with direct connection". Devices without an intermediate link have a higher efficiency, and are able to "curb" the most powerful high-voltage motor. Despite the fact that the price of this option is higher, the system in which it is implemented is much more economical in terms of costs.
• What is the cost savings? The fact is that such converters have a small frequency range, and it cannot be equal to or exceed the characteristics of the supply network. The standard frequency of the current in the network is 50 Hz, and the device converts it to 30 Hz and below, down to zero. Consequently, the consumption of electricity is reduced - here's the savings for you!

Such a limited range does not allow the use of converters of this type in industrial scale. But for household pumps, this is just what you need.

Selection of a pump for a well

First of all, it must be borne in mind that the power characteristics of the pump must exceed the calculated consumption. That is, there should always be a reserve of power.

The calculation is based on the following data:

• depth and
• Diameter casing pipe
• , and if it is simpler - the distance from the water mirror in the well to the surface of the earth with the pump running
• Total daily water consumption for a family, keeping animals and watering (calculated based on existing standards)
• Well distance from home
• Height of water supply (taking into account the number of storeys of the building)
• Pressure pipe diameter

The pump head for a well, from which water will be supplied directly to the house, is the sum of the length of vertical and horizontal distances, multiplied by the resistance of the pipeline - this coefficient is a constant value, and is equal to 1.15.

• If there is a storage tank in the water supply system, then the pressure of the hydraulic tank is also added to the sum of the distances. Pressure is expressed in atmospheres, and each atmosphere is equal to 10 vertical meters.
• Consider how the calculation will look like specific example. Let's say you have a well with a dynamic level of 35 m. It is located 20 m from two-story house 7 m high. At the same time, a hydraulic accumulator with a capacity of 60 liters and a pressure of 3 atm is installed in the house.

The calculation of the pressure will look like this: H \u003d (35 + 20 + 7 + (3 * 10)) * 1.15 \u003d 105 meters.

If we take into account a small margin, then you can buy a pump with a pressure characteristic of 110-115m. As you can see, the complexity this calculation does not represent. Now let's talk about the criteria for selecting a frequency converter, abbreviated PE.

Transducer selection

As for the technical characteristics of the inverter, they must be related to the type and power of the electric motor to which it will be connected. Further, it is necessary to take into account the required control range, as well as the level of tuning accuracy and maintaining the torque on the motor shaft.

• The design features of the inverter, that is, its dimensions, configuration, built-in or remote control, also matter. The vast majority of installed asynchronous motors. To them, the frequency converter is selected according to power, and it is better if this characteristic of the converter is an order of magnitude higher than that of the pump.

• There are converters with vector control that allow you to maintain the rotation speed under variable loads, as well as work without reducing the speed in the zero range. Such converters most accurately control the torque and shaft speed. This is especially important when there are two pumps in the network.
• In general, frequency converters have their own classification. Like any other electrical equipment, they can be single-phase and three-phase. The version of the inverters can be household, for a 220V network. There are also industrial converters with power up to 500V, and high-voltage converters up to 6000V.
• The degree of IP protection is also different. By type of control, PE are divided into vector and scalar. All leading manufacturers of pumping equipment offer consumers inverter units. Typically, manufacturers link converter models to specific pump modifications and give recommendations for their use.

The buyer does not even need to think much about the choice: the sales consultant will indicate to you the converter model suitable for this pump, and explain to you what are the features of its use.

Pumps used in systems autonomous water supply and heating, are productive, but at the same time quite costly equipment in terms of operation due to the high level of energy consumption. You can reduce costs and significantly extend the life of the pump by equipping it with a frequency converter, which we will discuss in this article.

You will find out why you need and what functions a frequency converter performs. The principle of operation of such devices, their varieties, specifications and recommendations are given for the choice of converters for borehole and circulation pumps.

1 Why do you need a frequency converter?

Almost all modern pumps sold in the budget and middle price categories are designed according to the throttling principle. The electric motor of such units always operates at maximum power, and the change in the flow rate / pressure of the fluid supply is carried out by adjusting the shut-off valves, which changes the cross section of the through hole.

This principle of operation has a number of significant drawbacks, it provokes the appearance of water hammer, since immediately after turning on the pump begins to pump water through the pipes at maximum power. Another problem is the high energy consumption and rapid wear of the system components - both the pump and the shut-off valves with the pipeline. Yes, and there can be no talk of fine-tuning such a water supply system at home from a well.

The above disadvantages are unusual for pumps equipped with a frequency converter. This element allows you to effectively control the pressure created in the water supply or heating pipeline by changing the amount of electricity supplied to the motor.

As you can see in the diagram, pumping equipment is always calculated according to the power limit parameter, however, in maximum load mode, the pump operates only during periods of peak water consumption, which is extremely rare. In all other cases, the increased power of the equipment is unnecessary. The frequency converter, as statistics show, allows you to save up to 30-40% of electricity during the operation of circulation and borehole pumps.

1.1 Device and operation algorithm

A frequency converter for water supply pumps is an electrical device that converts the direct voltage of the mains into an alternating one at a predetermined amplitude and frequency. Almost all modern converters are made according to the double current change scheme. This design consists of 3 main parts:

• uncontrolled rectifier;
• pulse inverter;
• control system.

The key design element is a pulse inverter, which in turn consists of 5-8 transistor keys. A corresponding element of the stator winding of the electric motor is connected to each of the keys. Foreign converters use IGBT class transistors, while Russian converters use their domestic counterparts.

The control system is represented by a microprocessor, which simultaneously performs the functions of protection (turns off the pump in case of strong current fluctuations in the mains) and control. In borehole water pumps, the control element of the converter is connected to a pressure switch, which allows the operation of pumping station in fully automatic mode.

The operation algorithm of the frequency converter is quite simple. When the pressure switch determines that the pressure level in the hydraulic tank has fallen below the permissible minimum, a signal is transmitted to the converter and it starts the pump electric motor. The engine accelerates smoothly, which reduces the hydraulic loads affecting the system. Modern converters allow the user to independently set the acceleration time of the electric motor within 5-30 seconds.

During the run-up process, the signal transmitter continuously reports the pressure level in the pipeline to the transmitter. After it reaches the required value, the control unit stops acceleration and maintains the set engine speed. If the water point connected to the pumping station begins to consume more water, the converter will increase the supply pressure by increasing the pump capacity, and vice versa.

1.2 Operation of the pump in tandem with a frequency converter (video)

If the pump you are using does not have a built-in frequency converter, then you can purchase and install such a power controller yourself. As a rule, pump manufacturers in the technical data sheet indicate which particular converter is suitable for this equipment model.

1. Power - the voltage converter is always selected based on the power of the electric drive to which it is connected.
2. Input voltage - indicates the current strength at which the converter remains operational. Here it is necessary to choose with an eye to the fluctuations that may be in your power supply (low voltage leads to the device stopping, at high voltage it can simply fail). Also consider the type of pump motor - three, two or single phase.
3. Adjustment frequency range - for borehole pumps, the optimal range will be 200-600 Hz (depending on the initial pump power), for circulation pumps 200-350 Hz.
4. The number of strokes and control outputs - the more of them, the more commands and, as a result, the operating modes of the converter, you can configure. Automation allows you to set the speed at start-up, several modes of maximum speed, acceleration rates, etc.
5. Control method - for a borehole pumping station, it will be most convenient to use remote control, which can be located inside the house, while a converter with a remote control is perfect for circulation pumps.

If you have filtered out all the devices on the market and are faced with the fact that there is simply no equipment suitable for its characteristics, you need to narrow down the selection criteria to a key factor - the current consumed by the motor, according to which the rated power of the converter is selected.

Also choosing a frequency control unit, especially from domestic or Chinese manufacturers Please note the warranty period. By its duration, one can indirectly judge the reliability of the technique.

A few words about manufacturers. The leading company in this area is Grundfoss (Denmark), which supplies the market with over 15 different models of converters. So, for pumps with a three-phase electric motor, the Micro Drive FC101 model is suitable, for single-phase pumps (operating from a standard 220V mains) - FC51.

More affordable in terms of price is equipment from Rockwell Automation (Germany). The company offers a line of PowerFlex 4 and 40 converters for low-power circulation pumps and a PowerFlex 400 series for borehole pumping stations (3 pumps connected in parallel can work from one converter at once.

Keep in mind that the price of a good converter can sometimes reach the cost of a pump, so the connection and configuration of such a device should be carried out exclusively by specialists.

In the article we will talk about how to organize automatic water supply using a frequency converter. Consider the choice of a converter, the compilation of an automation system, additional features on control, management and protection of the asynchronous motor of the pump.

To achieve efficient water supply and at the same time ensure maximum protection of the pump motor is possible only with the use of specialized converter technology, made on the basis of an autonomous voltage inverter. This solution allows you to organize the automation of uninterrupted water supply used both for your own needs and for industrial needs.

Regardless of the purpose for which the pump is used (borehole, pumping, self-priming, etc.), almost all the motors used in them can be divided into two types - single-phase and three-phase asynchronous motors. It is depending on the drive motor used in the pump that the required converter is selected.

What is a converter

This is an electrical unit that converts the electrical power of the network in accordance with the incoming task and outputs an adjustable voltage to the motor in the range from 0 to 220 V or from 0 to 380 V with a frequency of 0 to 120 or more Hz. Inside the converter is:

1. An uncontrolled or semi-controlled Larionov bridge, which provides rectification of the mains voltage, built on a semiconductor base of diodes or thyristors.
2. Capacitor link, smoothing the resulting voltage.
3. Key for resetting the voltage recovered during braking.
4. Autonomous voltage inverter based on IGBT switches, providing an alternating voltage of a given value and frequency.
5. Microprocessor control system responsible for all operations in the converter and motor protection.

Typical structure of a three-phase frequency converter based on an autonomous voltage inverter

Transmitter Selection Criteria

The first thing to consider is the suitability of the converter for the type of power supply (220 V or 380 V). The second is the correspondence of the power of the motor power converter, while it is desirable to have a small margin in terms of rated power for the purchased converter (on average by 20-50%), which will guarantee operation if the system needs to be turned on and off frequently, as well as in various emergency situations.

For ease of commissioning, the converter must have a control screen. Most modern converters already in the basic configuration have built-in blocks for processing discrete and analog signals, which in the future will make it possible to build a system of small automation on its basis, if they are not there, you need to order them.

One of options design of terminals used to connect discrete and analog signals to the converter

The main thing that the pump should provide is to maintain a given pressure value in the system with a constantly changing flow rate of the supplied water. At the same time, a slight decrease in the speed of rotation of the pumping part of the pump, performed by the converter, since the pump operates with a "fan" type of load, leads to a more significant decrease in the required torque electromagnetic moment and, as a result, to a decrease in energy costs.

Additional equipment for organizing automatic water supply

1. Analog pressure sensor.
2. System start/stop buttons.
3. Water temperature sensor (for deep pumps).
4. Input high-speed fuses.
5. output contactor.
6. Input and output choke (may not be installed at low powers).

Buttons "Start" and "Stop" are connected to the discrete inputs of the converter and acquire the necessary properties in the process of adjustment. The analog pressure sensor is connected to the corresponding analog input on the converter panel and is parameterized to set the speed of the pump motor.

How automation works

After pressing the "Start" button, the converter automatically turns on the output contactor and, in accordance with the readings of the pressure sensor, starts the pump motor. After that, it smoothly brings its speed to the required one to maintain the set pressure.

If the converter detects an emergency situation or when the Stop button is pressed, the converter reduces the motor speed to a minimum with the intensity required depending on the situation and turns off the contactor.

A water temperature sensor for borehole pumps is needed to indirectly control the temperature of the pump, since the use of a converter reduces the amount of water flow and, as a result, worsens cooling. This control can be neglected if the water temperature is guaranteed not to rise above 15-16 degrees Celsius.

If the motor has a built-in temperature sensor, it should be connected to the corresponding input on the converter, this guarantees 100% protection of the motor from overheating during operation.

What you need to know when assembling the circuit and setting up the converter

It is necessary to carefully read the instructions for the pump and converter. When setting up the system, it will be necessary to record in the converter information on the rated speed of the motor, its power, rated current, voltage and frequency of the supply network, the optimal acceleration and deceleration time, the permissible overload of the motor at start-up and during operation.

You will need to define the functions of the analog and digital inputs and output to control the contactor. After that, select the control law, in this system - U / F or vector control. After that, you will need to enable automatic paramitrization, during which the converter itself will determine the resistance of the motor windings, calculate all the parameters necessary to create its mathematical model.

All the necessary settings in modern digital converters can be made using the control panel with a liquid crystal display. A number of transducer models are supplied with special software, having installed it on a personal computer, it is possible to contact the control system via USB or COM port.

Converter control panel

It is important to correctly connect all components of the automation system and the engine. Most converters have a built-in 24V power supply that can be used for wiring diagrams and providing indications of system operation using digital outputs and LED lights.

Advantages of using the converter-pump motor system

When properly configured, the transducer monitors the pressure in the water supply system and protects it from exceeding the set pressure.

The converter itself turns on the pump motor and rotates it at the speed at which, in accordance with the water consumption, the required pressure is maintained, usually this speed is lower than the nominal one, due to which energy savings are achieved. The motor is accelerated within the time specified during commissioning (according to the so-called ramp), this option allows not only to reduce the starting current in the system and, as a result, motor overload, but also to minimize the load on the mechanical part, which prolongs the life of the pump and reduces overrun electricity.

Only with the help of a converter can pumps with a three-phase asynchronous motor be efficiently used when powered by a 220 V household power supply.

The protections built into the converter constantly monitor the current consumed by the motor, its rotation speed, temperature, which makes it possible to protect against short circuit, breakage of the supply phase, jamming of the mechanical part, overload and overheating.

Pumps are needed to adjust the power of the engines. As a result, the pressure in the system is maintained at the proper level. High-quality converters can save a large number of electricity. And this should be taken into account. In this case, pumps can be used in a variety of ways. The most common are systems for supplying water to the house. Also, converters are needed for circulation pumps. Additionally, they can be installed in fountains and aquariums.

Features of converters

The hallmark of all pump converters is their simplicity. At the same time, they do not require any maintenance and work completely automatically. Additionally, it is possible to control them through a personal computer. You can also set individual schedules for the device. At the same time, their efficiency is about 90%. You should also know that pumps with converters do not need expansion tank. Thus, the pressure is always maintained at an optimal level.

What are the characteristics of the converters?

Input voltage and power are considered important characteristics of converters. Additionally, the manufacturer always indicates the type of control. To date, there are scalar and vector regulation of the device. The rated current parameter depends on the power of the model. You can also highlight the output frequency. It is usually specified in the range from 0.1 to 600 Hz. The overload capacity is calculated as a percentage. The degree of protection of the converter housing is indicated by a special marking. Working temperature device manufacturer also in without fail indicated. Among other things, it is necessary to highlight the parameter of acceleration time, as well as braking.

Reviews of converters "Danfoss 2800"

The Danfoss frequency converter is quite easy to maintain as well as operate. In this case, dense installation of equipment is allowed. This is largely due to a reliable cooling system. To control the level of pressure in the device, special sensors are provided. Separately, it is worth mentioning the high-quality PID controller. The input is 220 V, and the power is 0.2 kW.

The output frequency ranges from 0.1 to 600 Hz. The frequency converter is controlled by a vector method. The full acceleration time takes an average of 30 seconds. Degree of protection of the body - class "IP20". The dimensions of this unit are as follows: height - 174 mm, width - 73 mm, and depth - 135 mm. The Danfoss 2800 frequency converter costs about 11 thousand rubles.

Model INVT GD10: specifications and reviews

Many customers appreciate these pump frequency converters for their large number of digital inputs. Among other things, the presence of a relay output should be highlighted. This converter can be used at temperatures from -10 to +50 degrees. The manufacturer provides a built-in PID controller.

Also, many positively appreciated the multifunctional keyboard. With its help, you can quickly access absolutely all parameters. The input voltage of this device The rated motor power is 0.2kW, and the frequency ranges from 0 to 400Hz. The rated current parameter is 1.6 A. The degree of protection of the housing is IP20 class. The overload capacity of this converter is 150%. This model will cost the buyer 12 thousand rubles.

Converter "Vesper E3-8100"

The frequency converter "Vesper E3-8100" is able to boast of its modest size. Among other things, it has special communication adapters that are designed for the network. It should also be noted convenient optional remote control. It is equipped with modern software. Printed circuit boards protection devices are lacquered.

Dense installation of devices by the manufacturer is allowed. The type of control in this converter is vector. The rated power of the device is 0.75 kW, and the output voltage is 22 V. The output frequency of the device fluctuates around 200 Hz. The total acceleration time is 30 seconds and the deceleration time is 50 seconds. The degree of protection of the case is set to the class "IP20". The unit can be operated at temperatures from -10 to +50 degrees. The frequency converter "Vesper E3-8100" costs 13 thousand rubles.

INVT GD15 Converter Parameters

Voltage regulation in this converter occurs in automatic mode. There are five digital inputs in total. The PID controller is built-in type. The manufacturer also provides support for all standard programs. The keyboard is multifunctional and provides quick access to the system. Separately, it is worth mentioning the EMC filter, which is built into the case. This single-phase control converter is of the scalar type.

The input voltage of the device ranges from 205 to 235 V, and the motor power is 0.4 kW. The output frequency is at around 300 Hz. In turn, the rated current indicator is 2.5 A. Within 10 seconds. the overload capacity of the converter is 180%. This model has the following dimensions: height - 140 mm, width - 80 mm, and depth - 134 mm. This device will cost the buyer 14 thousand rubles.

Reviews about the model INVT GD20

These frequency converters for pumps are in great demand and have good system protection. Analog inputs and outputs are provided by the manufacturer. Also of note is the built-in C485 port with support for many standard programs. The braking module is mounted in built-in type. The EMC filter is available in class C2. The protection system of the converter quite successfully copes with various kinds of interference.

If necessary, the remote control in the device can be easily disconnected. The dimensions of the converter are quite compact and at the same time its weight is only 1.5 kg. The rated power of the unit is at the level of 0.7 kW, and the frequency fluctuates around 200 Hz. The rated current parameter is 4.2 A. The device can be used at temperatures from -10 to +40 degrees. Separately, it is worth mentioning the good overload capacity. The control type, in turn, is of the scalar type. This frequency converter costs (market price) about 12 thousand rubles.

Opinion of buyers about the device "Hyundai 700E"

This Hyundai frequency converter differs from other devices by its high-quality PID controller. In this case, the braking module is installed built-in type. The control panel is quite convenient and is equipped with a potentiometer to control the speed. This model is suitable not only for pumps, but also for fans. Among other things, it is often installed on various conveyors. The EMC filter is of built-in type.

The drives for this model are suitable from different manufacturers, and this is very convenient. The device is installed quite simply and is comfortable to use. For commissioning, you can use "Flashdrop". The type of control in this model is classified as scalar. The input voltage of the device ranges from 200 to 240 V. In this case, the operating power of a single-phase motor is 0.37 kW. We should also mention the wide range of output frequencies. The rated current parameter is at the level of 2.4 A, and the overload capacity is 150%. The degree of protection in the converter is set to class "IP20". The height of this unit is 202 mm, width - 75 mm, and depth - 142 mm, with a mass of 1.1 kg. The Hyundai 700E frequency converter costs 12 thousand rubles in a specialized store.

Characteristics of the converter "Schnider AT12"

Connecting the frequency converter "Schnyder AT12" to the circulation pumps is quite simple. This model differs from other devices in compactness and high performance. Among other things, the versatility of the device should be noted. Manufacturers have paid much attention to the security system.

The overload capacity parameter remains 150%. The motor is single-phase, with a power of 0.18 kW. In this case, the rated current parameter is 1.4 A. The total acceleration time is 20 seconds, and the deceleration time is 55 seconds. The output frequency indicator is on average at around 250 Hz. At the same time, it can rise to a maximum of 400 Hz. In turn, the input voltage of the converter is 220 V. This model costs 14 thousand rubles in the store.

Model "Lovara H3"

Frequency converters for Lovar N3 pumps have acceptable characteristics, but have one drawback. It is associated with the formation of condensate. This largely depends on unprotected contacts. The possibility of synchronous operation in this model is provided. It should also be noted the versatility of the device. Starting and stopping the engine can be done remotely. Current signals are received from 4 to 20 mA.

Temperature environment should be between 5 and 40 degrees. Depending on the pressure in the system, the engine speed is controlled automatically. The input voltage indicator is at the level of 400 V. The rated power of a three-phase motor is 3 kW. This model will cost the buyer 15 thousand rubles.

Converter FC-051

The frequency converter FC-051 is actively used for pumps and ventilation systems. This model is distinguished by a high-quality control unit. It should be noted and a good interface of the device. You can connect this converter to a personal computer. The blocking of the mechanical seal occurs automatically.

If necessary, the remote control can be easily detached. At the same time, the device can be launched from any distance remotely. At high blood pressure works instantly protective system and block the engine. It also protects the system from various power surges. This model has an LED display. At the same time, only the most necessary indicators are available on the control panel. The noise level of the electric motor is within the normal range. This was largely achieved due to a high-quality variator that produces a stable frequency at 8 kHz.

There is a powerful fan to cool the entire converter. It is installed at the base of the frame and securely fastened. In this case, the device can be used for a long time and not overheat. Additionally, it should be noted that the tracking system constantly monitors the external pressure. On the centrifugal pumps this model can be installed. The control sensor can withstand a maximum output signal of up to 20 mA. This frequency converter costs (market price) about 16 thousand rubles.

The basic element that ensures the functionality of the pump is the electric motor. Previously, the adjustment of the workflow occurred due to automation, now this task is solved by a frequency converter for pumps.

Functional purpose of the frequency converter in the design of the pump

The inverter (frequency converter) regulates the operation of the pump much better than the relay. It works at the same time as a stabilizer, automation and workflow regulator. Thanks to him, the high efficiency of the device is ensured:

• The level of electricity supply, if necessary, and the engine speed are reduced, which helps to protect the pump from premature wear.
• The formation of excess pressure in the pipes is prevented.
• The problem with power surges is solved, which also definitely increases the life of the pump.

Mostly already in the process of assembling the pumping station is implanted. These devices include models of the very famous Grundfos pump.

Visually, it is a box equipped with electronics (several boards, a sensor that takes measurements, and an inverter that equalizes the voltage level) and a small-sized screen.

More expensive samples are equipped with microprocessors. Batteries, additional equalizers and so on can be built in.

The converters used can be of single-phase or three-phase type.

According to the principle of operation, the frequency converter is quite simple. A wave of electric current is applied to the boards of the device. Inverters and stabilizers located there ensure its alignment. At the same time, the sensor reads pressure data and other relevant information.

All information is redirected to the automation unit. Next, the frequency converter evaluates them, determining the power level that must be applied, and, in accordance with this, supplying the amount of electricity necessary to continue working.

As a result, the frequency converter can adjust the smooth start of motors, the water pressure level and stop operation in a critical situation. The list of all the "duties" assigned to the chastotnik is constantly expanding due to the improvements made by the developers.

The process of controlling the actions of the converter is carried out just by pressing the desired button, focusing on the data displayed on the screen. More expensive devices are able to recognize more commands. The highest quality models are designed for several dozen operating modes with a change in speed and program.

The cost of installation and purchase of the converter is fully compensated within one year of operation.

List of positive functions of the frequency converter:

• The ability to equalize the input voltage.
• Ensuring pump power control.
• Creation of conditions allowing to save the electric power.
• Increase the duration of operation of pumping equipment.
• Providing the ability to work without a hydraulic accumulator.
• Stabilization of intrasystem pressure.
• Reducing the noise level of the pump.

He also works as a substitute for automation.

Negative points:

• The high cost of the device.
• Configuration and connection is usually only available to specialists.

The frequency converter works in the design of the pump as follows: with a significant drop in the pressure level in the hydraulic tank (determined using a relay), the frequency converter receives the appropriate signal and gives the command to start the electric motor. At the same time, everything is carried out “without sudden movements”, the power increases gradually, providing insurance against hydraulic overload. Currently, converter models provide regulation of acceleration time from 5 to 30 seconds.

During acceleration, the converter constantly receives information about the pressure level in the pipeline. As soon as this level reaches the desired value, acceleration stops, the engine continues to operate at the reached frequency.

How to choose and install equipment?

The standard equipment of the pumping station consists of:

• Submersible or surface pump;
• pressure gauge;
• Hose equipped with stainless steel coating;
• Hydraulic accumulator;
• Water pressure switch.

To additional equipment include:

• Uninterruptible power supplies;
• Sensor;
• blocks;
• Control relays etc.

If the design of existing pumping equipment is not equipped with a frequency converter, then it can be implemented self-installation. Usually, in the documentation attached to the pump model, there are instructions regarding which converter a given type of pump can interact with.

In the absence of such information, it is necessary, based on significant parameters, to select the converter yourself:

1. Power level.

It is necessary to match the power of the electric drive and the converter.

1. Input voltage value.

An indication of the current at which the converter operates. Here it is necessary to take into account what potential fluctuations in the network can be (a low voltage level provokes a stop, a high voltage level causes a breakdown).

1. Pump motor category.

Single phase, two phase or three phase.

1. Limits of frequency control range.

For a well pump, 200 - 600 Hz is required (depending on what the primary power of the pump is), for a circular pump - 200 - 350 Hz.

1. Matching the number of control inputs/outputs to operational needs.

The more there are, the more possibilities workflow management.

1. Choice suitable way management.

In the case of a borehole pump, it is remote-type control, which allows control directly from home, and the circulation pump works perfectly with a remote control.

It is necessary to determine the reliability of the purchased devices indirectly by the duration of the warranty period. Accordingly, the larger it is, the better the quality.

Where to install the pump converter?

Frequency converters with hydraulic connection are installed directly on the pressure line. Without such a connection, only a water pressure sensor connected to the inverter is attached to the line.

Convert is located as close as possible to the pump, but only inside the heated room. General scheme connecting to the power supply is simple and hassle-free.

Pump transducer models

• Grundfos Cue

Converters manufactured by a company based in Denmark that manufactures pumps. As a result, these frequency converters are designed in maximum accordance with the design of Grundfos pump models. The device is responsible for the fine regulation of the operation of the entire mechanism, the performance of protective and control functions. The transducers of the Cue system are distinguished by a variety of high-quality models (more than 15 types in the range), but their cost is appropriate. In addition, the price directly depends on the frequency converter required for the mechanism of what power. Among the range of models, you can find converters for both a single-phase pump () and a three-phase one (Micro Drive FC101).

• Erman E-9

The converters of this company are budget-friendly. Responsible for torque compensation, smooth start, pressure control and have different modes number control up to 24. Compliance with power is selected on an individual basis. There is a protective housing that protects against dust and dirt.

• Hyundai N 50

Single-phase frequency converter. Can be used in household appliances. The power level is 0.7-2.5 kW. Small-sized, which makes it convenient to install in any devices. It is notable for the fact that it provides fine tuning thanks to several tuning modes and 16 discrete speeds. It costs about twice as much as the previous model.

• PowerFlex 40

Models of this brand are versatile and very popular. Them distinguishing feature— high-quality drive and vector control. The drive, among other things, dampens noise during engine operation, automatically picks up the speed of the electric motor, protects the entire mechanism from overload and overheating, and ensures a smooth start. Cost comparable to Grundfos Cue.

Using the pump in autonomous water supply and heating systems

Pump models in this category are considered very productive, but differ excessively high level power consumption, which, of course, complicates operation. Of course, frequency converters can reduce the amount of energy consumption, the level of pressure and extend the service life.

Most of modern pumps designed according to the throttling principle. The electric motors of these mechanisms are in operation at the upper power limit, that is, literally for wear. Often, due to the lack of smoothness when turned on, powerful hydraulic shocks are observed that spoil the design of the pump. To fine-tune such a mechanism, you also need to try hard.

The calculation of data for pumping equipment is always based on the power limit, although the mechanism experiences the maximum load only occasionally at peak water consumption, which happens infrequently. The rest of the time, the implementation of work at the limit of possibilities is completely unjustified. Just at such moments, the frequency converter for the circulation and borehole pumps reduces energy consumption by 30 - 40%.

Among other things, the use of a frequency converter in the pump station that provides water delivery helps to prevent the problem of "dry running". It is relevant in cases where there is no water inside the system, and the engine is running further. Due to the “dry run”, the engine may overheat and the mechanism as a whole may break. This once again proves the need to use a converter.

Single-phase frequency converter for a pump within a domestic water supply system

Ergonomics of devices is a very significant indicator in the framework of consumer services. Improving this parameter for a water supply system using a low-power single-phase pump model is difficult, since this requires a converter with an input / output voltage level of 1x220V, and it is not easy to find one.

Usually household pumps have no complaints about energy consumption, but this does not compensate for the cost of the purchase, due to its rare use.

However, the installation of the converter does not lose its relevance, since it helps to maintain a constant network pressure. In other words, a request for comfortable operation is made here.

This option is especially important when using hot water. That is, the use of a chastotnik eliminates temperature fluctuations and changes in pressure force.

Single-phase converters are suitable for both submersible and surface pumps.

Single-phase frequency converter for home use

Standard type converters are usually not equipped with a hydraulic connection. An attempt to independently upgrade the device for such needs may be useless, even if a specialist takes up the matter.

Recognizing this problem, frequency converter manufacturers have created a special single-phase frequency converter for a pump that supplies domestic water systems.

One of these converters is equipped with a hydraulic connection and is capable of performing all standard tasks chastotnik.