Main switchboard decoding, device, purpose. What is the difference between an ASU and a main switchboard?

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The main distribution board (MSB) is a distribution device that is responsible for receiving and further distributing energy throughout the building. Main switchboards can also be connected to networks with a solidly grounded neutral type of grounding:

• TN-C;
• TN-S;
• TN-CS.

Main switchboard

It can also be used to protect lines from overload, current leakage and short circuits. The device may contain emergency automation, as well as electricity metering devices. To purchase high-quality switchboard equipment, follow the link elektrika.ru. In this store you can expect low prices and high-quality equipment.

Electrical distribution board. What is inside

Electricity can satisfy almost all of our needs.
Thanks to it, we can watch TV, cook, do laundry, clean our house, work on the computer and much more. Do you know where the electrical part of any building begins? It starts with an electrical panel, more precisely with an input distribution board (IDU). And it doesn’t matter what it is, a huge skyscraper in a metropolis or a small wooden house in the village, you will find an electrical panel everywhere.

An electrical panel or shield, in general, refers to the location of electricity distribution and metering devices, power grid protection, as well as switching devices.

Depending on the purpose, the following types of electrical panels are distinguished: input distribution device (IDU), main distribution panel (MSB), distribution panel, group panel, floor distribution panel, apartment panel, metering panel, lighting panel, emergency lighting panel, panel ventilation, etc.

note

But to consider them all in detail, not a single sheet of paper and not a single article will be required. Therefore, within the framework of this article, I would like to dwell on the switchboard, which we constantly encounter in everyday life. For example, let's take an ordinary private residential building with a 380/220 V power supply.

The power supply to an individual residential building is carried out either from an overhead power line or by power cables from a transformer substation, which come to the input distribution device.

Energy supervision requires that electricity meters be installed in places accessible for readings by employees of this organization, although you have every right to install it directly inside a residential building. When installing a metering board outside on the facade of a building, it is necessary to use dust- and moisture-proof sealed panels.

In this case, the control panel can be mounted either separately or in a panel in the ASU. Moreover, the last option is the best technical solution.

To carry out proper installation of electrical wiring in a residential building, as well as for convenience during subsequent operation, additional distribution boards are installed after the ASU (for example: a distribution board on the first floor and a distribution board on the second floor). In these panels, electrical consumers are divided into groups (sockets, power, lighting, etc.).

As you can see, the switchboard is a necessary device. But before you start wiring and filling it, you need to know a few very important points. Firstly: the switchboard should be located in places that provide safe and unobstructed access to it.

Secondly: the design of the switchboard must correspond to the type of room (normal, wet, dusty, fire hazardous, explosive) in which it will be installed. And thirdly: it is necessary to choose a distribution board based on the characteristics of the electrical wiring of a private house.

Let's look at the main factors you should consider when doing this:

1. Wiring type

For hidden electrical wiring, it is recommended to choose internal panels that are installed in a specially prepared niche in the wall. The advantage of this type of shield is that it takes up little space and has an aesthetic appearance.

Important

If you have open electrical wiring in your house, then the ideal option in this case would be an overhead electrical panel.

The advantage of such a shield is that it does not require a specially prepared place for installation, but is simply attached to the wall using screws or dowel-nails, depending on the wall material.

2. Total power consumption and power of each individual group line

This is necessary in order to correctly select circuit breakers and protective devices. To connect groups of room lighting, corridor lighting, kitchen and bathroom lighting, automatic switches up to 10 A are usually used. To protect socket groups, automatic switches up to 16 A are used.

Protection devices for connecting powerful consumers are selected in accordance with their power consumption and conductor cross-section. That is, the rated current of the circuit breaker must be less than the maximum current for which the conductor is designed. I would like to remind you that the safety of people using electrical appliances directly depends on the correct choice of protection devices.

To protect a person from electric shock, an RCD with a rated leakage current of no more than 30 mA is used.

3. The number of circuits and points of consumption included in a single-line house power supply diagram

Typically, the electrical part of the house is divided into several groups: sockets, lighting, power, etc. Each group line is connected through a separate protection device. It is recommended for each high-power device (air conditioner, heated floor, oven, washing machine, water heater, etc.).

) also install a separate circuit breaker. After counting the number of machines, do not forget about installing a residual current device (RCD).

To increase the level of protection against electric shock, it is necessary to install an RCD on group outlet lines, lighting lines, water heater, washing machine, etc. In this case, it is mandatory to install an RCD to protect circuits supplying high-risk premises (bathrooms, showers).

Advice

It is prohibited to install RCDs for electrical receivers, the disconnection of which could lead to situations dangerous for consumers (disabling fire alarms, etc.). You should also know that installing RCDs in group lighting lines, as a rule, is not required.

The size of the electrical distribution panel should be selected based on the number of circuit breakers and protection devices. Don’t forget about the reserve in case you need to connect additional consumers during operation in the future.

In addition to automatic switches, the distribution panel must also have N and PE conductor buses installed.

Source: https://trigada.ucoz.com/publ/raspredelitelnyj_ehlektroshhit_chto_vnutri/1-1-0-437

Criterias of choice

There is no single model of equipment, so each project is developed according to a separate scheme. First of all, a detailed technical plan is drawn up, which takes into account the parameters, required power, and requirements for electrical circuits. Based on the location of the main switchboard, a suitable housing with the required level of protection from adverse external factors is selected.

The dimensions of the structure are taken into account: height, depth, width, number of panels, their placement. The need for additional elements is clarified: input, distribution, information reading devices, switches, backup power sources, for example, a generator.

The Elektromol LLC team uses Russian and foreign-made components in its work. You can order the required type of switchboards at a reasonable price. Each unit of input distribution devices complies with GOST standards and is tested according to all important parameters.

Types of electrical panels

14.12.2016

Electrical distribution panels are devices of various configurations that are used to transmit incoming electrical current to several smaller circuits and provide various types of protection to internal connections: for example, protection from overcurrent and overload in the form of fuses or circuit breakers, from environmental influences such as snow, rain, dust, etc., and also protect users from death and injury due to electric shock. This may be a large single panel or assembly containing cable connections, switches to redirect power, transformers, contactors, relays, insulators, fuses, and other protection and control devices.

Main switchboard configuration and examples of installed equipment

The main issue in the production of main switchboards is the list of names and manufacturers of components. Typically, when completing an incoming panel or sectioning panel, a combination of load switches and circuit breakers , or a withdrawable circuit breaker , for example EasyPact MVS, is simply installed.

Panels for automatic transfer of transfer switches may contain contactors with mechanical interlocks or machines with motor drives controlled by relay logic or a programmable controller. More details about AVR shields.

Power circuit breakers in a molded case or modular circuit breakers (depending on the currents) are installed in distribution panels

For status signaling and local control in the main switchboard, multimeters, ammeters, voltmeters, light buttons, touch panels and much more are used.

All components can be connected by cable or busbars (aluminum, copper).

Depending on the requirements of the project and the financial capabilities of the Customer, almost any equipment from any manufacturer can be installed in the main distribution board. Budget equipment is usually considered DEKraft, IEK, EKF. TDM. Components from Lsis, Hyundai, and Chint are considered average. Top equipment is Siemens, ABB, Schneider Electric, Legrand.

There is also a special segment of conditionally Russian electrical equipment - KEAZ, Kontaktor, DZNVA, etc., but in 99% of cases it is used only in special projects where they are fighting for import substitution.

Grsch - what is it?

The main switchboard (main distribution board) is understood as a device that distributes electricity within one building, structure or enterprise. Often it contains devices that allow you to keep track of energy consumption - meters.

Some manufacturers sometimes include automatic emergency devices in the main switchboard, which notify all employees of the enterprise about problems in the system.

It should be noted that main distribution boards have found their application not only on the territory of industrial complexes, but also in public buildings, for example, in kindergartens and schools.

A few words need to be said about the industrial production of main switchboards. Their installation is carried out between a special substation and an input device or directly in contact with the main consumer.

The design, development of a configuration plan and assembly of this device are directly related to the need to rationally distribute all incoming electricity, transmit it to each consumer in the required quantities, as well as reduce the risk of short circuits and all kinds of equipment overloads. Accounting for energy consumption, as mentioned above, is carried out using special meters. With their help, you can control your energy costs visually, at any time that suits you. Some enterprises engaged in the manufacture of main switchboards, as well as a distribution point included in the range of services they provide, can give the system they create remote control and recording of all results, which will be carried out automatically. After the main distribution board has been installed at the place where it is directly installed, it is necessary to connect it to power cables or special input busbars.

Requirements for the quality of manufacturing of the main switchboard and its configuration

It should be noted that the quality of assembly of the main distribution board is primarily influenced by the quality of the materials that will be used to manufacture the housing, as well as the correct installation of the equipment used.

note

In order for the products to fully comply with modern quality standards, it is necessary to establish the use of start-up and power distribution equipment of the highest quality.

In order to significantly increase the service life of the main switchboard, specialists began to introduce pieces of copper into the tires that are part of them.

Features of the main distribution board

First of all, the main switchboard must perform a protective and distribution function. The protective function appears during short circuits, because it is with its help that the entire emergency line is turned off, on which selective protection of all electrical equipment will be installed.

It also implies, in particularly critical situations, the activation of an emergency power system, which will help some devices survive until the equipment is repaired.

Also, by introducing logical control circuits into the main switchboard system, it was possible to make an almost instantaneous transition in automatic mode from the main input to the backup one, which allows for a smooth transition from emergency mode to operating mode.

This automation of the control of the main distribution board can significantly reduce the cost of its maintenance, and the number of company employees who need to work on it is significantly reduced.

Non-standard production of main switchboards

The management of some enterprises often wants to introduce a main distribution board into their production area, which will be manufactured in accordance with their wishes.

In such cases, the manufacture of the main switchboard occurs in a short time, regardless of the complexity of the work performed.

Important

In this case, the client is usually guaranteed complete confidentiality and uniqueness of the product, which will meet all requirements in the field of electrical engineering and be fully equipped. Delivery will be carried out in record time.

Source: “QUANTUM ELEKTRO”.

Source: https://www.pnzstroi.ru/repair/article/42002/grsch-chto-eto-takoe

Main switchboard project 0.4 kV

In the USSR, entire series of standard circuits and designs of main switchboards were developed for the same standard residential buildings, factories and factories. There, as a rule, at the input there was a VR-32 switch, typical AP50B circuit breakers or PN-2 fuses, and the names of the circuits included the typical names GRShch-800-01 or ShRS-1-7 or ShR-11-73505 or ShchO70-1 -1

Much time has passed since then, modern equipment has come to the market and main switchboard projects have become more complex and expensive. Today in Russia there are thousands of design companies of varying degrees of qualifications that create electrical panel projects throughout the country. We usually receive ready-made projects, which we either modify to meet the Customer’s requirements or redo them due to non-compliance with rules and regulations.

What is a main switchboard (main distribution board) in electrical engineering?

Main switchboard (interpretation: main distribution board) is a low-voltage device that receives and distributes electrical energy to electrical consumers. Carries out accounting, protects group lines from overloads and short circuit currents.

Installations use:

• in office buildings;
• in apartment buildings;
• at industrial enterprises;
• in medical institutions;
• at other facilities with increased electrical safety requirements.

Used in alternating current networks with a solidly grounded neutral, with a voltage of no more than 380 V and a frequency of 50 Hz.

The devices are installed near powerful energy sources - transformer substations and generators (gas, diesel, gasoline). The first are intended to power the main panels, the second - backup.

What does the main switchboard consist of?

The device is a prefabricated metal structure. It includes the following panels:

• input - include metering meters and units that receive electricity from the source;
• linear (distribution) - feed outgoing lines;
• sectional - contain automatic switches that allow you to power several sections from one input. Most often, an automatic transfer switch is placed here, used as a backup supply of electricity to consumers.

What does the main distribution box look like?

The products are equipped mainly with two inputs. In this case, they are divided into those that work for a common load or each for its own load. Power is supplied through a main busbar made of copper. Powerful boards are equipped with copper busbars, weaker ones with aluminum.

The use of UKRM allows you to compensate for reactive power. They reduce electrical energy losses. The units are part of equipment intended for large industrial companies.

The assembled device resembles a cabinet, divided into zones closed with doors. There are controls and indications on the doors. Depending on the type of design, the main switchboard is placed on the floor, suspended or built into the wall. Installed in rooms protected from moisture, radiation exposure, and vibration.

How does an ASU differ from a main switchboard?

The input distribution device is also used for receiving, metering, and further distribution of electricity to various objects. It is used to control the correct load distribution across the network.

Safety requirement when installing main switchboards

General labor protection requirements

• Only persons over 18 years of age are allowed to work in the distribution panel. Also, before working in the main switchboard, they must undergo a medical examination, induction training, initial training, as well as training and internship. The electrical safety level must be at least group 3.
• The work of a specialist must be defined by a work or job description.
• It is necessary to comply with internal labor regulations.
• Individual or collective protective equipment should be used correctly.
• If a situation arises that threatens people's lives, you must inform your superior. A specialist who works with the shield must undergo regular medical examination.
• During work in the cabinet, hazardous or harmful production factors may occur.
• The employee must be provided with special clothing, shoes and other personal protective equipment.
• As a result of injury, work must be stopped immediately and the supervisor must be informed.

Requirements before starting work

• You should select the necessary tool to begin the work. Tools must be visually inspected to ensure they are in good working order.
• Wear special clothing.
• Before carrying out work, inspect your workplace.

Requirements in emergency situations

• If faulty equipment occurs, the employee must notify his superiors.
• If the smell of gas is detected, work must be stopped immediately.
• Gas removal work should be carried out by professionals.
• If you are injured, you should stop working and contact a medical facility.
• If an accident occurs, then the victim needs to provide first aid.

Requirements while working

• Before starting work, the worker must make sure that there is no extraneous voltage.
• Warning signs must be placed on the outside of the internal door of the ShR type cabinet.
• The inlet hole, which is located in the cabinet, must be hermetically sealed.
• Before using a blowtorch, make sure there is no gas in the cabinet well.
• Smoking in the control cabinet during work is prohibited.

Requirements upon completion of work

• The workplace should be put in order.
• Close the closet.
• Gather all the tools.
• Inform management about any shortcomings you find in the shield.

Signs on the main switchboard

Features of the use of main switchboards

The main distribution board (abbreviated as main switchboard) is the most important device on the way from the transformer to the building's electrical networks.

Depending on the object being serviced, the equipment and functional features of the device may vary greatly.

In addition to the indicated main function, the main switchboard can make an emergency switchover to serviceable additional energy sources in the event of breakdowns on the main ones. As part of such activities, it performs a warning function. After all, it is with the help of the shield that the location and nature of the breakdown is established.

The main switchboard also performs additional control and accounting tasks. The latter are implemented by installing an electricity meter.

Advice

Another important function is the warning one. Using this equipment, you can monitor the presence of overloads in the network and prevent short circuits.

In addition, the switchboard performs management tasks. Simply put, it can be used to remotely turn off and on the power supply in individual parts of the building.

Taking into account the specified specifics of the equipment, its assembly, installation and connection should be carried out by a professional. The owner of the premises is only required to buy the main switchboard and pay for the work associated with the installation.

But before carrying out these actions, it is necessary to properly prepare the room. This should be a room suitable in size and parameters. Namely:

• humidity no more than 60%;
• temperature within 5-40 degrees Celsius;
• no vibration;
• eliminating the possibility of moisture ingress;
• normal level of background radiation;
• absence of aggressive and toxic vapors, gases, microparticles and dust.

The equipment itself is housed in a metal case, as it is manufactured in the form of a floor-standing cabinet that is installed vertically. It must have grounding, including around the perimeter of a specially designated room for placing the structure.

The door is a control unit. To diagnose the operation of the device, it is mandatory to install current and voltage monitoring units on it.

Often, the production of main switchboards is carried out by specialized enterprises to order, that is, for a specific application. As a rule, employees of the same company perform assembly, installation, and service maintenance of the mechanism.

Also watch a video describing the process of installing a distribution panel in an apartment.

Source: https://euroelectrica.ru/osobennosti-primeneniya-grshh/

Construction and design of main switchboard cabinets

Main switchboard cabinets, as a rule, are a floor-mounted prefabricated metal structure divided into panels (which are then conveniently disassembled, transported and reassembled).

The main switchboard may include:

1. Input panels (with and without automatic reserve entry)
2. Sectional panels (if there is an ATS according to 2in2, 3in1, etc. schemes). More details about ATS with partitioning
3. Distribution panels
4. Electricity metering panels
5. Reactive power compensation control panels , otherwise UKRM (KRM) boards
6. Motor control panels
7. Dispatch and control panels

An example of the layout of 2 main switchboards with BUAVR, sectioning, and electricity metering

6-panel main switchboard with PPU panel, 2 power inputs, electricity metering, automatic transfer switch, outgoing lines

Main switchboard cabinets have a lot of features, types, and designs. We tried to answer the most popular questions about the main switchboard.

What is the difference between VU, ASU, and main switchboard: the answer is in the standards

Introduction

Before finding out how the VU, ASU, and main switchboards differ, let us remember what the abbreviations given in the title of the article mean.

• VU is an abbreviation for input device;
• VRU is an abbreviation for input distribution devices;
• Main switchboard is the designation of the main distribution board.

All these devices share a supply circuit coming from substations or branches of overhead lines from the distribution networks of buildings, structures, houses and other electrical installations.

When planning the installation of an input device, you need to take into account the total power of all available electricity consumers in the house.

note

Particular attention is paid to houses heated by electric boilers. The boiler's power can account for the lion's share of the energy consumption of the entire house.

Calculation of boiler power is carried out by calculating the required heating radiators, their heat transfer and energy efficiency. Efficient bimetallic and aluminum heating radiators will help reduce the boiler power. Their prices are low, as you can see for yourself by looking at aluminum radiators in Ufa.

VU, ASU and main switchboard

It is important to note that VU, ASU and main switchboards belong to the same group of devices that have the same purpose in electrical circuits; they separate the supply electrical circuit from substations, transformers, VLI branches from the electrical circuit of a house, building, workshop, etc.

The input device on the site is installed on a support.

Hence, the second purpose of these devices is that they divide the areas of responsibility between the service organizations of the power supply networks of the city, town, district and the consumer.

• Applicable to a private house, everything that is located behind the VU, ASU and main switchboard is serviced by the owner.
• Applicable to an apartment, the areas of distribution of responsibility are somewhat shifted towards the end consumer (tenant). The VU, ASU and main switchboard at home are located in the electrical switchboard room, and the resident’s area of ​​responsibility begins after the floor switchboard, or apartment switchboard if it is installed in the apartment.

Marking of electrical panels

The wires of all internal circuits must be color coded. It must have a sharp contrast and be resistant to abrasion. Terminals for PE and N conductors that extend from distribution and group circuits should be marked with serial numbers. If connecting wires to the device terminals is difficult, then intermediate clamps must be provided. The clamps must also be marked with serial numbers.

A sign with information must be placed on the door on the outside of the main switchboard. Typically the nameplate contains the following information:

1. Manufacturer's name.
2. Type designation.
3. Device protection level.
4. Rated current of the ASU.
5. Weight.
6. Identification of all technical conditions.
7. Date of manufacture.
8. Additional Information.

Marking in the main switchboard

Photos of completed projects for the assembly of main switchboard cabinets

Main switch cabinet 1000A Legrand: DRX, DPX, TX3 circuit breakers, circuit breakers. ATS 2 inputs with sectioning

Main switchboard 3200A with AVR unit and sectional machine (7 panels) based on Hyundai and DEKraft components for a mining farm in St. Petersburg

BUAVR based on Zelio Logic relay, withdrawable automatic machines for 3200/2500A Hyundai UAN, aluminum busbar, outgoing lines automatic DEKraft BA-300

Modernization of the main switchboard for the hotel complex New Peterhof 4*

Main switchboard 400A (4 panels) for a residential building in Moscow based on ABB components

At the input there are OT ABB reversing switches according to the cross pattern, ATS is implemented on switches with fuses and contactors, all current-carrying parts are covered with plastrons

Main switchboard 1600A with sectioning and automatic transfer switch on MASTERPACT automatic circuit breakers / 8 panels

Input machines 1600A, sectional 1000A. 36 outgoing lines on Compact NSX Schneider Electric. Partitioning on Zelio Logic. Access to the machines is blocked by metal panels. Copper busbar.

Main switchboards 3200A based on the new Schneider Electric-MasterPact MTZ circuit breakers

Structural device and principle of operation

The decoding of the main switchboard, accepted in electrical engineering, sounds like “main distribution board.” It is a complete, low-voltage device equipped with a set of mechanisms for input, distribution and control over the volume of consumed electricity. The main switchboard provides protection for electrical outlet circuits in residential, as well as industrial and public facilities.

Initially, electricity from transformer substations is supplied to the facility's distribution panel. Several functional blocks, which represent the main equipment of the switchboard, are placed in separate panels and connected mechanically or electrically. The main functions of the main switchboard are:

• providing consumers with stable electricity;
• connection to power lines;
• ensuring quality and uninterrupted power supply;
• selective protection (in individual faulty units);
• prevention of current overload and resulting short circuit on input and distribution devices;
• automatic entry of reserve;
• accounting of consumed volumes of electricity.

The main distribution board can be connected to power both from the main inputs (transformer substations) and from backup sources (transformers, gas or gasoline generators, solar panels, wind generating plants). In normal operation mode, all consumers of the main switchboard are connected to it via a separate input. But in case of emergency situations, a group connection of consumers to power reserves is provided if its supply from the main input is interrupted.

Installation of panels is carried out in two ways: installation of a completely finished kit on site or assembly of individual components by specialists. The selection of the main switchboard is carried out based on its standard size, component units, tasks assigned to it and the value of the rated current.

Degrees of protection

Each main switchboard housing corresponds to the protection class assigned to it. These are parameters that reflect the possibility of installing panels outside or indoors. The most common are:

• IP20 or IP30 - equipment not protected from moisture, therefore suitable for installation only in dry rooms, without dampness;
• IP44 or IP54 - devices with increased protection against mechanical burglary and moisture. They can be installed in rooms with a high level of dampness, but without exposure to direct streams of water;
• IP55 and 65 are designs designed for operation in difficult environmental conditions, in rooms with an aggressive environment, and outside objects. They are equipped with reliable protection, allowing them to be placed outdoors without additional shelter. Moisture and dust resistance ensure data protection.

All overhead and floor panels are installed outside buildings: on special supports, on walls, stands or on their own body.

Metal or plastic is used to manufacture the housings of the main distribution boards. Metal structures are made entirely of this material or equipped with glass and plastic transparent inserts located on the front panel. Such inserts are necessary for periodic data collection or monitoring of equipment operation. Plastic boxes are smaller in size and are designed for installation inside buildings. For better sealing of the housing, the devices are equipped with rubber seals or dust- and moisture-proof input cables.

Main switchboards located on the streets are protected by locking mechanisms to limit access to them by unauthorized persons.