Pump control cabinet: types, connection diagrams, overview of popular models

Maintenance of an autonomous water supply system includes control over pumping equipment and serviceability of communications, conservation of the network during a long absence, and rational automatic control.

Automation is easy to implement by installing a pump control cabinet in a specially designated area - a compact distribution station operating in several modes. We will tell you in detail how to correctly assemble and install it. By following our advice, you can correctly connect the equipment.

We have provided a standard configuration of the control cabinet. We described what additional functions can be installed and used. The information proposed for consideration was supplemented with useful illustrations and videos.

Purpose and equipment of SCHOON

The technical content of different models differs, since control points have an individual functional focus.

Manufacturers offer ready-made standard circuits, but they do not always meet specific requirements, so there is such a service as manufacturing a custom-made control unit. To begin with, we will try to consider the general positions that unite all models.

Functional responsibilities of the control cabinet

The main function of any distribution station is to organize the operation of the equipment connected to it, in this case the pumping equipment. From one control panel (and this is convenient if the distance between objects is large), the motors of drainage, surface, and well pumps are effectively controlled.

The number of connected units may vary. Minimum connection – one borehole or submersible pump, which supplies water and ensures its availability throughout the entire water supply system (heating, fire extinguishing). In addition to it, a drainage pump is connected, which is necessary for pumping out water in domestic and emergency situations.

Automatic switching on/off of pump motors makes life easier for the owners of a private home, allowing them to spend their free time with their family, rather than manually switching toggle switches.

A few more convenient functions that can be “entrusted” to automation:

• control of network voltage necessary for uninterrupted operation of equipment;
• protection of mechanisms from power outages and short circuits;
• monitoring the water level in a well (or other reservoir) and responding to its shortage;
• recording pressure surges and adjusting optimal parameters (stopping the engine when a critical point is reached, starting when the indicators level out);
• remote control of well pumps, direct access to which is impossible;
• load distribution between several units or emergency connection of a backup option.

As a result of centralized automatic control operation of pumping stations becomes more productive, and the service life of electrical equipment is noticeably increased. Modern electronic systems allow you to program mechanisms and turn them on in a convenient mode (for example, only during the daytime).

Image of the housing and diagram of the control cabinet with starting-protective equipment and an automatic restart board for the backup load without specifying the specific modification (+)

All failures are recorded, and when an emergency occurs, an alarm is triggered. On the material side - saving energy costs and, accordingly, reducing electricity bills.

An example of a block diagram of automation of a pumping station with two connected pumps (380 V), which uses a variable frequency electric drive (+)

Brief description of standard equipment

The presence of certain elements depends on the number and category of pumps, narrow or broader technical capabilities, and the presence of additional functions.

Pump control Pressure 3.3: functional diagram of the device. Automatic shutdown and recording of an emergency situation occurs when there is an overload, “dry running”, or a change in the water level in the tank (+)

The basic equipment for most of the models offered for sale is as follows:

• Rectangular metal case with a control panel located on the front side. The design of the panel may differ, but it must have indicators and buttons such as “Start” or “Stop”.
• A switch (one or more) that allows you to turn the pump on/off manually.
• Fuses and protection elements.
• Control unit that regulates the voltage of three phases.
• Frequency converter required to control an asynchronous motor.
• An automatic control unit responsible for scheduled and emergency shutdown of equipment.
• A set of sensors showing water pressure and temperature.
• Thermal relay.
• A set of light bulbs – light signaling.

The main functions included in the control unit depend on several factors. For example, if there are 2 pumps, the main and additional (backup), a program is installed that allows you to turn on both mechanisms alternately.

Control panel for two pumps operating in standby mode. The advantage of interval switching is uniform load distribution and an increase in the planned resource

The temperature sensor protects the equipment from overheating and operation in dry running mode (the likelihood of such a situation often occurs in wells with insufficient flow). The automation stops the operation of the equipment, and when favorable conditions for water intake occur, it turns on the motor of the connected pump again.

Protection devices against voltage surges, phase failures, and incorrect connections protect mechanisms and prevent them from operating in emergency mode. They adjust the network parameters, and only after the parameters are equalized, they automatically connect the equipment.

Overload protection functions in much the same way. For example, there is a ban on simultaneous activation of two pumps, which leads to unnecessary costs and irrational use of equipment.

Almost all established systems have the ability to switch from fully automated control to manual control. This is necessary for maintenance, repair work, replacement of worn or burnt out parts.

Let's assume that if one pump fails, it can be easily removed and sent for repair by turning off the automation and using manual control.

Additional options and features

Various manufacturers include additional functions in the basic package that expand control capabilities. For example, the Alta Group company offers an AVR system - turning on backup power in automatic mode. The need for this function is explained by the fact that the operation of the pumping station is part of the life support system of the house, therefore, the network must operate in constant mode.

The operating principle of the ATS is as follows: as soon as the main power supply stops, the backup network is automatically introduced. It is valid until the main source resumes operation.

When it is turned on, the intelligent system checks the optimality of the parameters, and only if the response is positive, reconnects the main network. If the test analysis is unsatisfactory, the system will continue to operate from a backup source.

Low temperatures and high humidity are the enemies of the electronic filling of the cabinet, so manufacturers offer additional insulation services. It is relevant for the northern regions and for any areas if the equipment is located outdoors.

The so-called “warm package” is a layer of insulation laid on the inside. Thermally insulated SHUNs are operated over a fairly wide temperature range - from -40ºС to +55 ºС

A fairly common addition that helps protect pump motors from overload is a soft start system. It consists of a careful, gradually increasing voltage supply mode, thanks to which the engine is protected from a sudden start and is put into operation slowly and carefully.

Modern dispatch function allows you to manage pumping stations on distance. Remote warning systems are constantly connected to GPRS, a radio modem or the Internet, so that in an emergency, the blocking system is immediately activated and the signal is transmitted to the receiving device (phone or laptop).

A convenient option that allows you to set a specific program is possible through the use of a controller. In automatic mode, it is able to independently influence the operation of pumps, connect additional devices, and optimize the functioning of the system as a whole.

Indication involves the location of an electronic display on the cabinet lid with voltage and current readings, as well as statistical data: number of starts, engine operating hours, water volume

Another good option that allows you to obtain information about a system stop or an emergency situation is the installation of a light alarm and siren. When force majeure occurs, the flashing light lights up brightly, and a special sound device emits a loud, repeating signal.

Samples of electronic technical connection diagrams

The equipment is assembled in a production environment, where the schematic diagrams of the pump control cabinet are drawn up. The simplest are the connection diagrams for one pump, although a set of additional devices can complicate the installation.

As a sample, let’s take SHUN-0.18-15 (Rubezh company), designed for manual and automatic control of electric drives of a pumping station. The control diagram looks like this:

On the housing cover there are on/off buttons, a toggle switch responsible for selecting the operating mode, and a set of indicators indicating the serviceability of the system (+)

The manufacturer sells 19 basic versions, which differ in the power of the electric motor of the pumping station - from 0.18 kW to 55-110 kW.

Inside the metal case there are the following elements:

• automatic switch;
• protection relay;
• contactor;
• backup power supply;
• controller.

For connection, a cable with a cross section of 0.35-0.4 mm² is required.

Sample connection of model SHUN-0.18-15 (for a drainage or fire pump) from the manufacturer Rubezh with one drive and a controller that regulates the operation of the equipment (+)

Grantor SHUNS, designed for drainage work, control asynchronous motors and have two control options: manual and automatic. Manual adjustment is made from the front panel of the housing, automatic adjustment operates from external relay signals (electrode or float).

Triple diagram showing the operation of a cabinet for 1, 2 and 3 pumps with float control. If there are 2 or more pumps, load distribution between operating and standby equipment is proposed

The principle of operation of the SHUN in automatic mode: with a critical decrease in the water level in water well and the activation of float No. 1 stops the operation of all pumps. When the liquid level is normal, float No. 2 is activated and one of the pumps starts. When other floats located at higher levels are triggered, the remaining units are introduced.

Features of installing monitoring stations

Without exception, all versions of SHUN are complex devices operating from an electrical network, which means that it is necessary to install, commission, maintain and repair the equipment in accordance with the manufacturer’s instructions. The rules set out in the instructions for different models may differ, since the design of the mechanisms and technical characteristics are also different.

Electrical connection diagram of the pumping equipment control cabinet OWEN SCHUN 1. Thanks to the use of branded OWEN frequency converters, energy savings reach 35%

A few general important rules:

• Installation is carried out in an explosion-protected area.
• The temperature and humidity in the room must correspond to the parameters specified by the manufacturer (for example, temperature from 0ºС to +30ºС).
• Connection of electrical equipment must be carried out by a person with special permission.
• The parameters of the SHUN must match the parameters of all connected equipment.
• Installation is carried out according to the circuit diagrams given in the appendix to the instructions.
• The cable cross-section must match the data specified in the instructions.

Household control stations located in the private sector are subject to the same requirements as industrial control points. They must be installed in a dry and warm place that is convenient for maintenance. This could be in the basement, a designated area, an extension to the house or a secure utility room.

Unlike large industrial cabinets, household models are compact and lightweight, so they are most often produced in a wall-mounted version

Connection should be made after completely water supply system installed, a pressure pipeline has been installed, cables have been laid, components have been assembled, and all electrical elements have been insulated. After connecting the SHUN, you should check its operation in both manual and automatic modes.

Technical support and service

Some control cabinet companies claim that no maintenance is required. This is true, but regular checks of the control unit by the operating organization are necessary. There is a frequency established by the manufacturer, and for the correct operation of all devices it must be adhered to without fail.

Before inspecting or replacing any parts, turn off the power and secure the equipment from being turned on again. You can check the reliability of the connections yourself.A list of potential faults, as well as possible ways to eliminate them, is usually also indicated by the manufacturer.

Control cabinet for a well or submersible pump with a frequency converter for use in industrial boiler houses, public utilities or private homes, custom-made according to individual specifications

For example, the simplest malfunction is that the light indicating that the system is connected to the electrical cable does not light up. There are three possible reasons: there is no voltage in the network, the circuit breaker or the lamp has burned out. Accordingly, the solution to the problem will be to supply voltage, replace the switch or lamp.

If a malfunction occurs that cannot be corrected on your own, you must contact a specialist service center.

Brief overview of popular models

Although it is possible to make custom-made schooners, many companies offer basic models. They are assembled based on consumer demand. We offer a brief description of cabinets that can be purchased or ordered on the official websites of companies or in online stores.

SCHOON Grundfos Control MP204

Grundfos Control MP204 control cabinets are designed for automatic operation and protection of one pump.

The parameters in Grundfos Control MP204 can be configured in manual and automatic mode, and there are two threshold values: the first is a warning, the second is an emergency shutdown. A trip log listing the reasons for the response is stored in memory

Specifications:

• Voltage – 380 V, 50 Hz
• Motor power of connected equipment – ​​from 1.1 to 110 kW
• Temperature range – from -30°С to +40°С
• Protection degree: IP54

The advantage is the ability to transfer CIU data and adjust parameters via Grundfos GO.

SUN from NPO STOIK

Control stations for pumping units (PSU) from the company NPO STOIK. Designed for automatic control of submersible water intake and drainage pumps, capable of servicing from 1 to 8 connections.

Sample design of a 30 kW SUN in a metal hinged case with an Aucom soft starter and a Delta frequency converter

Specifications:

• Voltage – 380 V, 50 Hz
• Motor power of connected equipment – ​​from 0.75 to 220 kW
• Temperature range – from -10°С to +35°С
• Protection degree: IP54

Among the basic functions is the automatic activation of ventilation if the temperature inside the cabinet rises above normal.

Cabinets from the Grantor brand

Multifunctional cabinets of the Grantor brand are designed for servicing circulation and drainage systems.

Possible operating modes: circulation and drainage using an analogue sensor or pressure switch. Two variants of the operating algorithm involve simultaneous or alternate activation of pumps

Specifications:

• Voltage – 1x220 V or 3x380 V, 50 Hz
• Motor power of connected equipment – ​​up to 7.5 kW per motor
• Temperature range – from 0°C to +40°C
• Protection degree: IP65

If an emergency occurs and the pump motor breaks down (due to a short circuit, overload, overheating), the equipment automatically turns off and a backup option is connected.

Cabinets Wilo SK

The SK-712, SK-FC, SK-FFS lines from Wilo are designed to control several pumps - from 1 to 6 pieces.

Several automatic circuits in the Wilo SK-712 cabinet greatly simplify the operation of pumping stations

Specifications:

• Voltage –380 V, 50 Hz
• Motor power of connected equipment – ​​from 0.37 to 450 kW
• Temperature range – from +1°С to +40°С
• Protection degree: IP54

During operation, all technological parameters are displayed on the display. In the event of an emergency, an error code is displayed.

Conclusions and useful video on the topic

You can learn more about how pump control cabinets function in the following videos.

How to make the simplest SHUN with your own hands:

An example of the operation of a typical SHUN on a test bench:

The use of pump control cabinets allows you to efficiently use the resources of well or drainage equipment and save energy. Knowing the technical characteristics of your pumping station, you can purchase a basic SHUN model or place an order according to an individual scheme.

Would you like to share your own experience, tell us how you assembled, installed and connected the pumping equipment control cabinet? Do you have any interesting information or questions that arose while reading the information we offer? Please write comments.