To connect and correct operation objects in the electrical field, various devices and instruments are used that have a specific function. An ASU is designed to connect a line to several objects simultaneously (with a local network). The decoding of this abbreviation in electrical engineering sounds like “input distribution device”. It is designed to perform various functions and is additionally equipped with metering devices.

Scope of operation

The main purpose of the equipment is to receive and then further distribute the input electricity. Input and distribution devices are designed for operation at any type of facility, including industrial, household, and construction. Devices must comply with the parameters of the electrical network: voltage and power consumption. The process of assembling and completing the ASU is strictly controlled; a number of strict requirements are imposed on them; all actions are performed only manually.

Manufacturers offer both universal models designed for networks with standard parameters, as well as special ones. The location of distribution devices in buildings is always indicated in the power supply project. It also indicates the characteristics of all equipment included in the kit. After installation and assembly, authorized persons seal the meters in order to block unauthorized access to particularly important devices.

In private households, the installation of input devices is justified only if it is necessary to distribute the total load over several objects, For example:

• summer cuisine;
• outbuildings;
• bath;
• garage.

In such cases, the main block is installed, and then a separate switchgear is installed for each of the buildings.

Equipment configuration

All models are equipped in different ways, depending on the requirements placed on them during operation or the individual wishes of the future owner. The standard equipment includes protective automation and measuring equipment, In addition, the components of the ASU are:

Depending on the field of operation, switchgears are equipped with quartz fuses and transformers, as well as voltage limiters. Each project represents a set of individual requirements and parameters for organizing the power supply of a facility.

Main functions

In addition to the main function - receiving and distributing incoming electricity, ASUs perform a number of other functions. Thanks to them, at the installation site it is possible to combine all devices into a single system and carry out comfortable and safe control from one point. Installation of distribution devices allows:

The lowest voltage device is the VRSH. Explanation of the abbreviation - introductory switchboard. This is the main equipment included, which monitors and manages electrical networks, and also provides protection against interruptions. The equipment is presented in the form of several functional blocks, which are located in panels with mechanical or electrical connections. It provides input and distribution of input energy to group users.

Classification and types

The device classification system is based on rated current indicators (250A, 400A, 630A), as well as on the additional number of devices included. Manufacturers offer several types of ASU:

• equipped with automatic switches;
• with lighting devices;
• with compartments for connecting measurement and control devices.

In the private sector and in apartment buildings Models that provide the possibility of separately connecting an RCD (device) are relevant. protective shutdown). This function increases the safety of using electrical networks and electrical appliances in particular. If an emergency occurs, a short circuit occurs, your hands touch a bare wire, or there is a voltage drop, the automation will turn off the power.

Equipment equipped with light sensors is intended for outdoor installation. As a rule, these are installed in in public places, in the entrances, on staircase landings, vestibules common use. Models equipped with automatic on/off switches for equipment are the most compact in size and are the most popular in the household sector.

The technical design of the devices determines their classification into floor-mounted and suspended, as well as by location - outdoor or indoor.

Installation features

The functioning of the ASU depends not only on technical parameters, but also proper installation at the site of operation. When purchasing equipment, you must ensure that there is a certificate of compliance with all standards confirming the quality of the product. In addition, an analysis of requirements is carried out: for uninterrupted operation, protective mechanisms and automation are checked, as well as the possibility of installing them at entry and exit points.

Connection of input distribution devices is carried out in strict accordance with the color marking of cables and wires. When purchasing devices, it is important to correctly calculate the required network voltage and current. Installation of equipment is carried out in strict accordance with design documentation.

Typical cabinet layouts VRU-1, VRU-2 were developed back in the USSR for power supply of residential buildings and industrial buildings. They covered the entire range of needs of the then designers, engineers and power engineers. Switchboards VRU-1, VRU-2, VRU-3, etc. with switches and fuses are still found in budget projects (sometimes they are called differently, or).

The ASU shield is metal structure wall-mounted or floor-mounted. Inside there are mounting panels on which the equipment is installed. ASU boards design there are single panel And multi-panel.

Single panel ASU switchboards are equipped with various devices for receiving and distributing electricity from the main source to individual groups of consumers; it also contains electricity meters.

Multi-panel ASU panels contain two or more panels on which additional equipment necessary for a specific electrical installation is installed. Such panels are:

introductory (contains the equipment of the input and accounting unit);

input with automatic input of reserve (input panel containing a block with ATS equipment);

distribution (metering blocks, automatic and non-automatic blocks can be located on this panel automatic control lighting, etc.);

panel of fire extinguishing devices.

ASU panel with changeover switch

If 2 power cables are suitable for the ASU and there is no need to automatically switch between them, two reversible (changeover) switches are installed at the input, connected in a cross pattern to provide power to certain particularly important consumers in groups. If the circuit is even simpler, you can simply install one reversing switch at the ASU input and switch between inputs to one common load.

Cabinet ASU photo

ASU cabinet for 630 A, KEAZ equipment	100 A ASU cabinet with GSM data transmission on KEAZ equipment	ASU panel 250 A, Hyundai components	ASU panel 400 A, Hyundai components
Cabinet VRU 630A 2 inputs, switches according to the “cross” pattern. ABB equipment	ASU cabinet for 125 A, input components KEAZ, ABB distribution	ASU cabinet for 200 A, Hyundai equipment	ASU 1250A 2 panels with ATS based on Hyundai circuit breakers with motor drive

The final stage in organizing the electrical transportation network is the installation of distribution and converting devices. They can also be found at intermediate nodes of trunk lines, but this concept of branching energy delivery circuits is most clearly manifested at the stage of direct supply to final objects. Input distribution devices (IDUs) such as transformers, fuse switches, etc. are responsible for this function.

Concept and purpose of ASU

As the name suggests, ASU systems perform the tasks of inputting and distributing electricity at consumption sites. Physically, an ASU is a set of technical means that provide power control, current conversion, its measurement in various parameters and accounting. For a more complete understanding of what an ASU is, it is worth familiarizing yourself with some modifications of devices and their purpose. So, at a basic level it is used next classification:

• VRU-1. Complete input and distribution equipment, which is used for operation outside switchboard rooms. Such devices can be found on staircases or in basements.
• VRU-2. Professional sets of control and control equipment designed for use in switchboard rooms. They can be used to ensure the operation of server rooms and technical electrical utility rooms.
• VRU-3. Small-sized kits that can be part of an electrical panel of a suitable format.

The most commonly used means are VRU-1 and VRU-3. These are devices directly involved in the processes of receiving, accounting and distributing energy in networks at 220/380 V with a frequency of 50 Hz. Some modifications additionally perform protective functions in cases of overloads and short circuits.

Operating principle of the ASU

The work process begins with receiving electricity from the main network. The power cable supplies current to the input automation in accordance with standard values ​​(rated current). Already at this stage, counters and other measuring instruments that measure the parameters of the input current can be switched on. Again, it’s worth recalling what an ASU is in terms of functionality. This is a complex of different devices, sometimes performing tasks of a completely different spectrum. In parallel with the measuring function, a protective function can be performed. Thus, the input switch generally controls the power supply and, when deviations from standard values ​​are detected or emergency situations occur, it turns off the machine. Technically, the switch is implemented in the form of a switch or disconnector - manual or automatic.

Next, a group of arresters comes into operation, ensuring the connection of wires in phases. At this stage, the voltage parameters are necessarily recorded and, if necessary, they are corrected by transformers. Distribution is carried out in groups of wires using circuit breakers with different or similar ratings. The current parameters on each circuit depend on the needs of the consumer to which it leads. The branching task is not determined by the separation of wires according to current characteristics, but by the need to distribute energy in its own directions for each supply point. Distribution automation ensures load uniformity between phases, fixing the demand coefficient of electrical networks, taking into account their maximum load.

Composition of the Verkhovna Rada

Almost all devices of this type are made in the form of a panel enclosed in a metal box. The following devices and functional blocks are placed on this base using pre-installed connectors and modules:

• Circuit breakers.
• Meters that record reactive and active energy.
• Current transformers.
• Converters.
• Test devices.
• Electromagnetic starters.
• Measuring instruments (voltmeters, ammeters, multimeters, etc.).

Additional equipment depends on the specific set of device functions. They have several panels with control equipment for one-way maintenance. The peculiarity of such equipment is the possibility of independently connecting an auxiliary distribution cabinet with a source uninterruptible power supply(UPS) in case of loss of power to the target object.

Characteristics of the ASU

Most input distribution systems are oriented towards work in three-phase and single-phase networks power point from 100 to 400 A and frequency 50-60 Hz. As for power, then First level represent input and distribution devices from 0.4 kV to 1 kV. They are used to service municipal lighting systems, construction equipment at remote sites, etc. However, to supply large consumers, switchboards with ASU are used, the power of which is at least 10 kV, and sometimes exceeds 25 kV. The choice also takes into account such characteristics as connection time of the backup source (0.2-5 s), degree of protection (from IP00 to IP31 depending on the part of the case) and electrical resistance (from 10 MΩ).

ASU of residential buildings

To service multi-apartment residential buildings, devices for three-phase networks with alternating current, in which a solidly grounded neutral is provided. Among the main tasks in this case are electrical protection of the line in cases of short circuits, overloads and emergency power outages. What is a physical ASU for a residential building? This is a metal cabinet with provided by grounding, in which meters, switches, protection units, emergency panels for entering UPS, load distribution sensors, etc. are installed. In modern designs, the doors of such boxes provide an indication of key parameters of the electrical network.

Implementation of ASU at industrial facilities

First of all, multi-panel cabinets are used, designed for branched control of several energy supply circuits. Power indicators and the degree of protection with insulation in this case are higher, but in small enterprises or in individual workshops with normal conditions In operation, household automatic machines can also be used. But what are ASUs intended for operation on large public and industrial facilities? On this moment factory-assembled cabinets of the ShchO-70 line are widely used. From a design point of view, these are panels for one- and two-way control, which also include automatic transfer switches and switches designed for long working sessions in a mode independent of the main power source.

Installation of ASU

Installation of a cabinet with an ASU is carried out on the basis design scheme, compiled in accordance with the operating conditions at the specific location of application. First, mounting holes are drilled to secure brackets and screws for the metal structure. According to the instructions, the installation of input and distribution devices is carried out at a height of at least 30 cm, and a dielectric insulating ceiling must be provided between the rear panel and the wall. There are also floor structures, the installation of which is carried out on a special foundation or platform, which is attached to concrete screed.

Connecting equipment

After installing the ASU housing, the functional filling is assembled and connected. An aluminum armored circuit is used for cable entry. It is directly connected to the switch and control relay. Next, crimped wires extend from the relay into separate functional segments. Input distribution devices VRU-1 have two input blocks that can be connected to different supply networks. But an insulating partition must be maintained between them. At the final stage, the separated and connected wires are fixed with nylon ties at the bottom of the panel.

Conclusion

ASU systems perform important tasks in organizing electrical networks. The functionality of such equipment can be considered both as control and measuring, and as protective and control. Even 0.4 kV input distribution devices give ample opportunities regarding control of the operation of the laid network, taking into account the volumes of supplied energy both at the input and output. But the main task still lies in the physical distribution of power supply channels while ensuring a sufficient degree of reliability and safety of equipment operation. IN latest models The ASU also places emphasis on improving control ergonomics with expanded automatic functions.

GOST R 51732-2001

STATE STANDARD OF THE RUSSIAN FEDERATION

DEVICES
INPUT-DISTRIBUTION

General technical conditions

GOSSTANDARD OF RUSSIA

Moscow

Preface

1 DEVELOPED by JSC Central Design Bureau "Elektromontazh" INTRODUCED Technical Committee on standardization TC 331 “Low-voltage switching equipment for distribution and control” 2 ADOPTED AND ENTERED INTO EFFECT by Resolution of the State Standard of Russia dated April 5, 2001 No. 169-st 3 INTRODUCED FOR THE FIRST TIME

Introduction

This standard was developed with the aim of providing regulatory support for the development and implementation in production of input distribution devices that meet modern regulatory requirements for electrical installations of residential and public buildings different number of storeys, as well as the requirements of IEC standards regarding electrical and fire safety. The standard contains requirements for input and distribution devices used in high-rise and low-rise residential and public buildings (see. building codes SNiP 2.08.01-89, SNiP 2.08.02-89, SNiP 2.09.04-87), as well as in individual houses and cottages. This standard, in contrast to GOST 19734-80, contains requirements regarding the possibility of connecting input distribution devices to four- and five-wire supply (distribution) networks with a solidly grounded neutral (type of system grounding, respectively, TN - C and TN - S or TN - C - S according to GOST 30331.2-95 / GOST R 50571.2-94). This standard takes into account the requirements established by GOST R 51321.3-99 for switchgear used in places accessible to unqualified personnel. The standard provides for input distribution devices installed in individual houses and cottages, two methods of protection against electric shock, defined by classes I and II according to GOST R IEC 536-94. For input distribution devices installed in multi-storey and low-rise buildings (up to five floors), class I is established. Appendix B provides a method for determining the rated currents of ASUs and the rated operating currents of devices built into them.

STATE STANDARD OF THE RUSSIAN FEDERATION

INPUT AND DISTRIBUTION DEVICES
FOR RESIDENTIAL AND PUBLIC BUILDINGS

Are commontechnicalconditions

Input-distributional boards for dwellings and public buildings.
General specifications

dateintroduction 2002-01-01

1 area of ​​use

2 Normative references

3 Definitions

4 Classification

5 Basic parameters

6 General technical requirements

6.1 General requirements

6.2 Construction

6.3 Internal circuits

6.4 Terminals

6.5 Accessories

6.6 Degree of protection

6.7 Protection against electric shock

6.8 Electrical characteristics

6.9 Protective coatings

6.10 Reliability

6.11 Marking

6.12 Basic information about the ASU given in operational documents

6.13 Completeness

6.14 Preservation and packaging

7 Safety requirements

8 Acceptance rules

8.2 Acceptance tests

Table 6 - Acceptance testing program

8.3 Qualification tests

Table 7 - Qualification and periodic testing program

8.4 Periodic testing

8.5 Type tests

9 Test methods

1 - dynamometer 1; 2 - sling; 3 - sling device; 4 - VRU; 5 - dynamometer 2

Picture 1

Load holding time of sling devices - 10 min. Sling devices are considered to have passed the test if the devices themselves or their connections to the frame have not ruptured, or cracks and tears have not appeared in them. Notes 1 Sling devices can be tested on a tensile testing machine using an appropriate fragment of the ASU, which ensures that forces are applied to them at a given angle. 2 If the mass of the test sample is not the maximum for a given type of ASU, then bringing the load to the maximum value should be achieved using dynamometer 2 (see Figure 1). 9.13 The presence of a jumper between the protective and zero operating busbars is checked according to 6.3.15 visually, and the reliability of its connection to the busbars is checked with the appropriate tool (wrench, screwdriver). 9.14 Checking the color marking of the zero protective and zero working conductors, as well as the presence of the designations “PE” and “N”, respectively, on the zero protective and zero working busbars according to 6.3.16 is carried out visually. 9.15 Checking the cross-section of copper conductors of metering circuits according to 6.3.20 is carried out visually. 9.16 Checking the compliance of wire insulation with a voltage of 660 V according to 6.3.26 is carried out according to their markings in accordance with GOST 18690 and/or a certificate. 9.17 Checking the digital marking of wires of internal circuits and the designation of prefabricated phase busbars according to 6.3.27 is carried out visually and by comparison with the electrical diagram. 9.18 Checking the marking with serial numbers of terminals for zero working and zero protective conductors of distribution and group circuits according to 6.4.6 is carried out by comparison with the design documentation. 9.19 Checking the marking of terminals for protective conductors of power supply networks with a grounding sign according to 6.4.7 is carried out visually. 9.20 Checking the compliance of the types of devices used in the ASU and their characteristics with the requirements of 6.5.1-6.5.15, 6.7.7 is carried out by comparison with the design documentation. 9.21 The marking of devices according to 6.5.16 is checked by comparison with the electrical diagram, their parameters according to 6.5.17 - by comparison with consumer orders and the location of devices according to 6.5.18 - according to the design documentation. 9.22 Checking the degree of protection according to 6.6 should be carried out in accordance with GOST 14254. The ASU must be tested for the degree of protection in the installed position with external conductors connected. Evaluation of test results - in accordance with GOST 14254. 9.23 Checking the electrical resistance according to 6.7.5 between the terminal for connecting the neutral protective conductor of the supply network and the conductive parts of the ASU is carried out by measuring the resistance with an ohmmeter with the appropriate measurement limit. 9.24 Checking the functioning of the device controls in accordance with 6.7.8 is carried out by turning the devices on and off three times, and clear fixation in the “on” and “off” positions must be ensured. Checking duplicate designations of devices, if provided, is carried out visually. At the same time, the correct direction of movement of the device controls is checked in accordance with 6.7.9 by comparing the actual direction of movement with that specified in the technical specifications for specific types of ASUs and GOST 21991. 9.25 The presence of class II ASU markings in accordance with 6.7.10 is checked visually. 9.26 Checking the connection of the secondary windings of current transformers with the zero protective busbar PE is carried out visually, while checking the reliability of the connection of the conductors with the terminals of the current transformers and with the zero protective busbar, using the appropriate tool (screwdriver, wrench). 9.27 Checking for the presence of a voltage warning sign on the outside of the doors according to 6.7.12 is carried out visually. 9.28 Testing the ASU for temperature rise over 6.8.1 9.28.1 Testing of cabinet and single-panel ASUs, as well as panels of a multi-panel ASU for temperature excess, is carried out with their rated currents in the operating position under normal climatic conditions in accordance with GOST 15150. 9.28.2 Values ​​of the rated currents of the ASU (rated operating currents of the input devices), as well as the values ​​of the rated operating currents of the protective devices of the distribution units and their quantity, which must be used during testing, are taken in accordance with the technical specifications for specific types of ASUs. Note - The values ​​of rated currents of ASUs and rated operating currents of protective devices of circuits, as well as their quantity used during testing, are established in the technical specifications for ASUs of specific types in accordance with Appendix B. 9.28.3 Rated current of ASUs of cabinet-type or single-panel ASUs, and also, panels of a multi-panel ASU with distribution units must be distributed between protective devices of distribution and group circuits in such a way that its rated operating current flows through each protective device involved in testing. Note - It is allowed to load one three-phase or three single-phase devices from among those used for testing with a current less than the rated operating current of the device in order to achieve equality of the total operating current of these devices to the rated current of the ASU or panel. 9.28.4 The temperature rise test is carried out with three-phase and/or single-phase current. The voltage of the test circuits is not standardized. Note - Test three-phase current is preferable, since in this case all elements of the internal circuits of the ASU can be simultaneously included in the test circuits. 9.28.5 When testing cabinet and single-panel ASUs with three-phase current, protective devices of distribution and group circuits, including group circuits of the lighting control unit, are connected to three-phase adjustable circuits, each of which is connected into an artificial star. In each phase of these circuits, a test current should be installed (and maintained during testing) equal to the rated operating current of the protective device with an error not exceeding ±5%, while the value of the test current in each phase of the input device should not have a deviation of more than ± 2% of the rated current of the ASU. 9.28.6 When testing cabinet-type ASUs and single-panel ASUs with single-phase current, protective devices and associated elements of internal circuits that are part of the distribution unit and lighting control unit are connected in series to the test circuits for the corresponding rated operating currents, and the poles of the input device of each ASU - in series into the test circuit for the rated current of the ASU. The input block fuses and busbars are included in the same circuit. Notes 1 If, when testing with single-phase current of the ASU, not all terminals (for example, on busbars) could be inserted into the test circuits, then their tests are carried out separately. 2 If the design of the terminals on the zero operating N and zero protective PE busbars is identical to the tested terminals on the phase busbars, then they may not be subjected to temperature rise tests. 9.28.7 Testing for temperature rise of multi-panel ASUs can be carried out separately for each panel or ASUs consisting of two or three panels, one of which is with an input unit, and the rest with distribution units, and the total operating current of the protective devices of the distribution units must correspond to the rated current of the ASUs , and at least one panel with a distribution unit must be loaded with its rated current. In the first case, tests can be carried out with both single-phase and three-phase current; in the second case, it is preferable to carry out tests with three-phase current. 9.28.8 When testing the input panel with single-phase current, the poles of the input device are connected in series into the circuit under test, which also includes fuses, sections of busbars located in the input panel, and flexible inter-panel jumpers designed to connect these sections with the busbars of panels with distribution units . Notes 1 If, when testing with single-phase current, not all terminals (for example, on busbars) of the ASU could be inserted into the test circuits, then their tests are carried out separately. 2 If the design of the terminals on the zero operating N and zero protective PE busbars is identical to the tested terminals on the phase busbars, then they may not be subjected to temperature rise tests. 9.28.9 If the input panels (diagrams No. 5-7, Appendix A) contain two input devices, then they and the elements of the internal circuits related to them are included in the test circuits one by one. 9.28.10 Single-phase current testing of multi-panel ASU panels with distribution units is similar to that described in 9.28.6. 9.28.11 Testing of multi-panel ASUs with three-phase current, panel by panel or as an assembly, should be carried out as described in 9.28.5. 9.28.12 To supply test current to the ASU or to the input panels in accordance with 9.28.8, the conductors of the test circuits are selected according to the rated current of the ASU. Conductors for performing test circuits, which include protective devices of distribution units and automatic switching units for public lighting, are selected according to the rated currents of the devices. 9.28.13 Testing for temperature rise of the protective bus PE according to 6.3.1 should be carried out together with the zero operating bus N with a jumper installed between them according to 6.3.15, for which the test conductors should be connected to the terminals available on them (for the corresponding conductors of the supply network) circuit and set a current in it equal to 50% of the rated current of the ASU. 9.28.14 The selection of cross-sections and lengths of copper conductors of test circuits is in accordance with GOST 22789, but not less than the cross-sections of conductors of internal circuits. The ends of the test circuit conductors must be thoroughly stripped and securely connected to the terminals of the devices and the corresponding terminals. 9.28.15 When conducting tests, temperature measurements must be carried out using thermocouples on the ASU elements specified in Table 5. The installation locations of thermocouples are in accordance with the technical specifications for specific types of ASU. These locations must be indicated in the test reports. Note - Temperature measurements of insulated conductors combined into bundles or laid in boxes must be performed on conductors with worse conditions cooling. This also applies to flexible interpanel bridges. 9.28.16 The duration of the temperature rise test is until a steady-state thermal regime is achieved, at which the temperature change is no more than 1 °C/h. 9.28.17 Temperature monitoring of ASU parts, as well as ambient air, must be carried out in accordance with GOST 22789. 9.28.18 ASU is considered to have passed the test if the temperature of their parts exceeds the established one upper value ambient air temperature is not more than the permissible values ​​​​according to 6.8.1. The insulation resistance of live parts measured at the end of the test must be at least 6 MΩ. 9.29 Testing the ASU for short-circuit current 9.29.1 Single- and multi-panel ASUs are subjected to tests for electrodynamic and thermal effects with a short-term withstand short-circuit current according to 6.8.2. 9.29.2 The test three-phase alternating current circuit includes: in single-panel ASUs - an input unit and busbars, in multi-panel ASUs - an input unit with its busbar, as well as busbars of one panel with a distribution unit. Note - If two input blocks with the same rated current are located in the input panel, then one of them may be tested. 9.29.3 When preparing to test the ASU for the effects of short-circuit current, it is necessary: ​​a) the busbars are securely connected at the ends opposite the power supply with short-circuiting jumpers with a cross-section equal or equivalent in conductivity to the cross-section of the busbars; b) turn off the protective devices of distribution and group circuits; c) short-circuit the secondary circuits of the current transformers; d) block the protective devices at the input to prevent them from triggering earlier than the time set in 6.8.2 when a short circuit current flows. Note - Circuit breakers can be bridged with jumpers, fuse links are replaced with current-carrying elements with low resistance. 9.29.4 For the test circuit, insulated conductors must be used, selected according to the rated current of the ASU. Conductors must be secured so that they can withstand the mechanical effects of short-circuit current flowing through them. 9.29.5 Before connecting the ASU to the test three-phase circuit , it must be calibrated according to the oscillogram in such a way that it achieves a short-circuit current, the average effective value of which in three phases must be equal to or close to the value according to Table 2 for the corresponding ASU, while at least in one of the phases the peak value is reached current (see table 2) with an error not exceeding ±5%. 9.29.6 The conductors of the test circuit must be connected to the input terminals of the input device. The current value in the test circuit with the ASU connected should be close to or equal to the value obtained during calibration of the test circuit. The current flow time in the test circuit is 0.2 s. 9.29.7 The impact of short circuit current on the elements of the ASU included in the test circuit must be one-time. 9.29.8 The test results are considered positive if there is no damage or destruction of the supporting insulating elements on which the busbars and other live parts are installed, or there is no deformation of the busbars and flexible jumpers that reduce the electrical strength of the insulation due to a possible reduction in air gaps and creepage distances. The input device must not have any damage that would prevent its further proper operation. The devices and devices that are part of the tested ASU or ASU panel, but which were not included in the test circuits, should also not be damaged. The heating temperature of busbars and other non-insulated current-carrying parts of the ASU included in the test circuit should not exceed 200 °C, taking into account the temperature they had before the test; conductors with polyvinyl chloride insulation - no more than 160 °C. 9.29.9 Tests of the ASU for the effects of short-circuit current can be carried out with a conditional short-circuit current according to 3.6.7, equal to the value of the rated short-term withstand current according to Table 2, while the circuit calibration and testing must be at a voltage equal to 1.05 of the rated operating voltage voltage. The duration of the short circuit current is until the input protective device is triggered. The procedure for calibrating the test circuit and conducting the test is in accordance with GOST 22789. 9.29.10 To check the resistance of the zero operating busbars N of single- and multi-panel ASUs to the electrodynamic and thermal effects of short-circuit currents, the corresponding current should be passed through them once, the value and time of exposure of which tires are specified in 6.8.2. 9.29.11 To carry out tests according to 9.29.10, the zero operating bus N should be short-circuited with the nearest phase bus. The short-circuiting jumper must have a cross-section equal to the cross-section of the zero operating busbar. The conductors of a single-phase test circuit must be connected: one to the phase bus (after the protective device), the second to the zero bus N, using a clamp for connecting the zero working conductor of the supply network. The cross-section of the conductors of the test circuit must be equal to the cross-section of the zero operating bus N or equivalent to it in conductivity. 9.29.12 Zero running tire N is considered to have passed the test according to 9.29.10 if it has not undergone deformation with the consequences set out in 9.29.8, and its heating temperature does not exceed the value specified in 9.29.8. 9.29.13 To check the reliability of electrical connections between the open conductive parts of single- and multi-panel ASUs and the PE zero protective bus according to 6.7.2, these parts and the protective bus should be included in a single-phase test circuit and a short-circuit current should be passed once, the value and duration of which specified in 6.8.2. 9.29.14 Before testing according to 9.29.13, the ASU or panel must be isolated from the floor and third-party conductive parts. The conductors of the test circuit are connected: one to the terminal for the protective PE or PEN conductor of the power supply network, and the second to the shell of a single-panel ASU or panel of a multi-panel ASU at the most distant point from the said terminal. The cross-section of the conductors of the test circuit must be equal or equivalent to the cross-section of the PE zero protective busbar. 9.29.15 The electrical connections of the ASU parts with each other and with the PE protective bus are considered reliable if, after testing for short-circuit current in accordance with 9.29.13, the electrical resistance measured between the connection points of the test circuit conductors does not exceed 0.1 Ohm. 9.30 Measurement of air gaps and creepage distances according to 6.8.3 should be carried out with measuring instruments installed in the technical specifications for specific types of ASUs. 9.31 Testing the electrical strength of the insulation of internal circuits according to 6.8.4 and shells made of insulating material according to 6.8.5 should be carried out in accordance with GOST 22789. Tests of multi-panel ASUs are carried out panel by panel. When testing ASUs of all types, the meter should be turned off and the jumper removed according to 6.3.15. Evaluation of results - in accordance with GOST 22789. 9.32 Insulation resistance measurements according to 6.8.6 are carried out: between current-carrying parts of different phases, between phases and the neutral working conductor (with the jumper removed according to 6.3.15), as well as between them and the PE protective bus. Measurements must be carried out with a megohmmeter for a voltage of at least 1000 V. Measurements are carried out with the counters turned off. 9.33 Inspection of paint and varnish and powder polymer coatings according to 6.9.2 and 6.9.3 (appearance, coating thickness) should be carried out in accordance with GOST 9.032 and GOST 9.410, respectively. The adhesion strength of coatings is in accordance with GOST 15140. 9.34 Inspection of metal coatings according to 6.9.4 should be carried out in accordance with GOST 9.302. 9.35 The reliability test according to 6.10 is carried out in accordance with the technical specifications for specific types of ASUs. 9.36 Checking the marking of the ASU according to 6.11 is carried out by comparing it with technical documentation. 9.37 Control of the operational document according to 6.12.1 should be carried out for compliance with GOST 2.601 and for completeness of its completion according to 6.12.2 in relation to the ASU of the corresponding type. 9.38 The completeness check according to 6.13, 6.7.6 is carried out for compliance with the requirements of technical specifications for specific types of ASUs. 9.39 The preservation and packaging of the ASU according to 6.14 is checked visually. 9.40 The probability of a fire occurring in (from) the ASU is determined in accordance with the methodology given in GOST 12.1.004 (Appendix 5).

10 Transportation and storage

11 Operating instructions

12 Manufacturer's warranty

APPENDIX A

(required)

Schematic diagrams of inputs to the ASU

L - phase conductors; N - zero working conductor; PE - neutral protective conductor; PEN - combined neutral working and protective conductor; P - jumper according to 6.3.15

Note - Application of diagrams for the corresponding type of ASU - according to Table 1.

APPENDIX B

Approximate layout of equipment in the ASU

Figure B.1 - Equipment layout diagrams in input panels of multi-panel ASUs: a) with one input; b) with two inputs; c) with two mutually redundant inputs with ATS equipment

Figure B.2 - Equipment layout diagrams in distribution panels of multi-panel ASUs:

a) with a distribution unit powered from one input; b) with distribution and metering units powered from one input; c) with distribution units powered from two inputs; d) with distribution, metering and control units for general house lighting, powered from two inputs

Figure B.3 - Layout of equipment in a single-panel ASU

Figure B.4a - Layout of equipment in a class II cabinet ASU (with an insulating shell)

Figure B.4b - Layout of equipment in a cabinet ASU of class I (with a conductive shell)

APPENDIX B

Determination of rated currents of ASUs and rated operating currents of devices built into them

APPENDIX D

Designations of ASU types

Examples of designations for the types of panels of a multi-panel ASU Input panel ASU, 4th design, manufacturer N, for a rated current of 360 A, digital designation 102, Climatic performance UHL4:

VRU-4N-360-102 UHL4

Distribution panel ASU, 4th design, manufacturer N, rated current 200 A, digital designation 210, climatic version UHL4:

VRU-4N-200-210 UHL4

Note - If the distribution panel is powered from two inputs (see paragraph B.11 of Appendix B), then their rated currents should be indicated as a sum, for example VRU-4N-(120+80) UHL4. An example of a type designation for a single-panel ASU ASU of the 02nd design, manufacturer N, for a rated current of 200 A, digital designation 301, climatic version UHL4:

VRU-02N-200-301 UHL4

An example of designation of the type of ASU cabinet version ASU 003 design, manufacturer C, rated current 100 A, digital designation 405, climatic version UHL4:

VRU-003-100-405 UHL4

Key words: input and distribution devices for residential and public buildings, general technical conditions

For connecting internal electrical networks of electrical installations to external power supplies cable lines, as well as for the distribution of electrical energy and protection against overloads and short circuits of outgoing lines. input (VU) or input-distribution devices (IDU).

The input device is also intended to delineate responsibility for the operation of electrical networks between city network personnel and consumer personnel. Behind the input device Electricity of the net are under the control of the consumer. When powering small-power electrical installations belonging to the 3rd category of uninterruptible power supply via one cable, three-pole BPV type input boxes are used as input devices for currents of 100, 250, 350 A with one block of “PN-2 fuses and a circuit breaker. Also used are Y3700 boxes with one three-pole automatic switch of the A3700 series for currents of 50 - 600 A. For three- and five-story residential buildings, ShV series cabinets are used as input devices.

Input and distribution devices for public buildings

For public buildings, high-rise residential buildings and small enterprises, ASU input and distribution devices are used, made in the form of one-way or two-way service panels. Any input-distribution device is completed from input and distribution panels, or factory-made cabinets. In large cities, electrical installation companies develop and use their own design series of ASUs.

Introductory panels are manufactured the following types: VR, VP, VA. The input panel equipment is designed for rated currents of 250, 400 and 630 A.

On the VR-250 input panels for currents of 250 A, PN-2-250 fuses, a switch R or a switch switch of the RP series are installed. On the input panels VP-400 and VP-630, switches-switches of the RB series and fuses PN-2-400, switch-switches of the series RB and fuses PN-2-630 are installed, respectively. VA panels are installed circuit breaker A3726 series for a rated current of 25 A.

Distribution panels are manufactured in the following types: distribution panels with automatic switches on outgoing lines, distribution panels with automatic control of staircase and corridor lighting, distribution panels with metering department. The distribution panels are equipped with automatic circuit breakers of the A37, AE20, AE1000 and AP50B series, magnetic starters of the PML series, intermediate relays RPL and package switches PV, PP.

When assembling the ASU, the input and distribution panels of one input are located side by side. ASU panels are manufactured by the manufacturer as separate panels with built-in devices and instruments, as well as connecting conductors between the panels.

The figure shows circuit diagram one of the input panels with a switch for one input.

Thanks to the large variety of input and distribution panel circuits VRU-UVR-8503, any ASU can be configured according to the given electrical circuits for powering the internal networks of buildings.

Scheme of the input panel with a switch at the input: 1 - measuring instruments, 2 - current transformers, 3 - electricity meter, 4 - anti-interference capacitors, 5 - fuse, b - switch, 7 - cable input, 8 - circuit breaker, 9 - incandescent lamp

At large enterprises that consume significant power, input and distribution cabinets and factory-made panels of the ShchO-70 series are used as input and distribution devices. They are also used at substations in distribution devices 0.4 kV. Structurally, they can be single-sided or double-sided. Switches with fuses or automatic circuit breakers of the AVM series are installed on the input panels, and switches with fuses or automatic circuit breakers of the A37 series are installed on the distribution panels.

Panel panels for one-way maintenance are installed directly against the wall of the electrical room. They are served with front side. Panels of double-sided service panels are called free-standing or free-standing and are located at a distance of at least 0.8 m from the wall.

Single-sided service panels require less area for installation and maintenance than double-sided service panels. In addition, they are more economical. However, double-sided service panels are more convenient to use.

In addition to panel-type switchboards, factories produce input-distribution and distribution switchboards assembled from separate blocks: fuse, circuit breaker, fuse-switch, circuit breaker, meter.

The premises of input and distribution devices (electrical switchboards) are located in convenient places, where only service staff. Gas pipelines should not pass through electrical switchboards, and other pipelines should be without connections, valves, or gate valves. It is allowed to install ASU not in special premises, but on stairwells, in corridors, etc., but the cabinets must be locked, the handles of the control devices must not be brought out or be removable. It is not allowed to install ASU in damp rooms and in places prone to flooding.