Installation of an electrical switchboard: assembly and connection of a 220 V unit

Any home, office or industrial premises are equipped with many electricity consumers. In order for it to reach the end point, a power supply circuit of the object is created and laid. Before any cabling begins, a location is determined for the installation of the switchboard, which is the heart of the energetic circulatory system. It performs a protective, accounting and dividing function of power supply into streams.

Appointment of the electrical panel

All electrical products related to this type, whether main, distribution or group, serve one purpose:

• Ensuring the receipt of electricity from the input source.
• Separation of voltage streams on separate lines.
• A clear and timely response to network faults.
• Protection against electric shock.
• Some devices perform an accounting function.

These tasks are entrusted to a fairly compact device equipped with the necessary devices. All rules and requirements for it are regulated by GOST and PUE.

Formation of electrical lines

Dividing the wiring diagram into separate groups has several goals. Firstly, it is the clarity and selectivity in the response of protection devices. This makes it possible to de-energize in the event of a malfunction, not the entire facility, but only the emergency one. Secondly, the distribution of capacities allows you to reduce the cost of electrical installation work by choosing a cable with a smaller cross-section.

There are several guidelines for separating electrical streams:

• A separate group includes energy-intensive consumers with an individual power of more than two kilowatts. This is the connection of automatic devices for washing and washing dishes, electric ovens, boilers. Installation is carried out with a flexible cable of at least two and a half square cross-section and is connected to a sixteen-amp circuit breaker.
• If there are more powerful consumers, a separate supply line and a group in the distribution board are allocated for them. The cable cross-section is increased to four square millimeters, the circuit breaker - up to 20 amperes.
• Welding machines require the installation of a separate post with an automatic machine with a rating of at least 32 amperes and a cable cross-section of six squares in copper.
• Socket lines are made for each room. If there is a ground loop, the wiring is carried out with a three-core cable with a cross section of 1.5-2.5 squares. The nominal value of the machine is selected based on the number and power of future consumers. Typically 10 amps is sufficient.
• Lighting is also provided separately. With the use of the latest LED devices, the load on such a leash has significantly decreased, so the cable is chosen with a conductor cross-section of up to 1.5 square, an automatic 6 ampere. All requirements are also set out in the relevant documents.

Varieties of devices

As for the material used in the manufacture, these are metal and plastic. Plastic lighter and whiter are attractive in appearance. Metal ones are more reliable. With the introduction of new painting technologies, the design of iron cabinets has noticeably improved and fits into the interior of a modern home.

According to the installation method, they are external and embedded. Wall cabinets take up more space. Among the manufacturers, the products of Legrand, Schneider Electric, Interelektrokomplekt are widely represented. Almost all equipment is manufactured in our country using high-tech equipment.

The boards are completed with PE and N busbars for earth and zero, as well as a DIN rail on which machines, RCDs, and meters are installed.

Development of a schematic diagram

Any serious undertaking starts with drawing up a plan. In this case, a single-line diagram of the electrical panel wiring is developed. You can do this yourself, having wiring skills, but it is better to contact a specialist. In such a drawing, the number of vertical lines corresponds to the number of selected groups. The figure also indicates similar devices:

• Introductory automatic device. Its rating is calculated based on the ratings of all incoming circuit breakers with a 20 percent reserve.
• Input device of protective shutdown. It is also chosen with a margin at par.
• Group circuit breakers and RCDs.
• Load disconnect switch.

All electrical devices are indicated by conventional signs prescribed by GOST indicating their characteristics.

Mounting accessories

To fully provide housing with energy resources, an optimal protective complex and a metering system, it is necessary to formulate the requirements for the composition of the equipment inside the switchboard.

Case selection

For small apartments, the installation of a hidden switchgear is best.. The material of manufacture and design delights in this case do not play a role.

For housing equipped with a large number of energy-intensive equipment and, accordingly, an extensive network of wires, it is a good idea to purchase a cabinet with collapsible walls and removable DIN rails. The length of such a rail should ensure the installation of all devices with a margin for possible additional connections in the future.

Protection and disconnection devices

Any device included in the power distribution cabinet is selected according to the appropriate characteristics:

• Rapid response for machines.
• The magnitude of the breaking current for the RCD.
• Current rating.
• For contactor devices, the frequency response to operate.

All equipment is selected specifically for each consumer group. The main thing is that they are harmonious. An imbalance in favor of the line breakers will lead to an emergency situation throughout the facility. This is due to the increased response threshold of the input equipment and the large time interval for cutoff.

Independent group shutdown ensures selectivity of protection. This is accomplished in two ways. Firstly, the rated current of the lower-level circuit breakers, group ones, must be less than that of the input one. Secondly, if the group includes machines of the same rating, then the speed of operation of the lower device should ensure its priority shutdown.

When choosing the characteristics of an RCD, you need to build on the fact that this device is quite expensive and install it must be combined with a circuit breaker, the data of which allows it to be disconnected earlier. Connection to the power supply circuit is recommended for the following premises:

• Sanitary - technical cabins.
• Separate lines for powerful energy consumers.
• Rooms for children.

For such consumers, an RCD with indicators from 10 to 30 milliamperes is suitable. For protection against fire, it is recommended to install modifications with an operating current in the range from 100 to 300 milliamperes.

Additional accessories

As a rule, a minimum installation kit is already included in the kit. However, it is impossible to prepare equipment for individual needs. You will have to buy something yourself.

The most essential accessory is the DIN rail. The main and auxiliary equipment is attached to it. It can be one or several, it all depends on the scale of the project. In terms of capacity, it must be consistent with the dimensions of the board and the number of devices. Reserve required. To ensure insulation from the body, the strips are attached through special dielectric spacers.

Also, various terminal blocks for connecting live parts require an insulated installation. They must provide a reliable connection of the conductors. It is good if they are covered with a transparent cover to protect against accidental touch. Through it, you can see the heating of the connections in case of loosening of the terminal clamps. Models available for DIN rail mounting.

To combine several wires into a group for subsequent connection to one connection, there are special two or more positional crimping lugs.

By purchasing special combs, you can connect several devices to one power source. They are easy to install, provide a reliable contact connection and save space in the panel. And also their use allows you to clearly see the entire circuit, which is difficult to trace with a large number of wires.

DIY assembly steps and rules

Before starting to assemble an electrical panel with your own hands, 220 V or 380 V, it is necessary to create all the conditions for comfortable work. It is necessary to check the availability of tools and a complete set of equipment, fasteners, cable products. Prepare a flashlight with a charged battery. It is necessary to check the circuit and determine the correspondence of the picture with the output wires.

The installation of the shield is divided into several stages:

• Preliminary work. These are all operations for the immediate preparation for the installation of an electrical panel. For this:
  • Plugs are removed, additional holes are drilled (if necessary).
  • The door and wall panels are dismantled, which will interfere. All rails and terminal blocks are installed.
  • The hinges are screwed on for installation.
• Next, it pretends that the cabinet corresponds to the prepared place. For ease of installation, all devices that can be installed are mounted in their places, because it is inconvenient to perform such work in a suspended box.
• Fitting outgoing wires. Before installing the shield, it is necessary to check the correspondence of their number and measure the required length. A small margin is left and the excess is cut off. It usually starts them from the bottom, but with a large number of wires, some of the wires can be pushed through from above.
• Then the outer insulation is removed. On the wires, you can pre-apply additional marking with colored tape. This will avoid phasing errors.
• Before installing the box, wires are wound up, including the input. It is necessary to distribute them in the order in which they will be connected.
• The cabinet is then set to a permanent position. The fastening of all equipment is carried out in strict accordance with the diagram.
• Initially, the input equipment is installed, then the meter, RCDs with automatic machines and group switches.

Connect the cables in order. From which side it does not matter. There are some rules to follow:

• All wires during the installation of the electrical panel with their own hands are laid horizontally and vertically.
• Bends - 90 degrees.
• The veins are exposed by about 10 millimeters.
• Ferrules are crimped onto a flexible wire.
• All connections are tightly pulled.
• According to unwritten rules, the input is connected from above, consumers from below.
• Non-stripped wire areas should not be pinched in the terminal blocks.
• For ease of installation and subsequent operation, the groups of wires must be assembled into bundles and fixed with plastic clamps.

The power is connected to the input device after the voltage is completely removed and the indicator is checked. The cores are pulled tightly at the terminals. If there is a ground, the contact is connected to a separate terminal block. After the introductory machine, the metering device is connected and then in groups.

At the final stage of the assembly of electrical panels, it is necessary to visually check the correctness of all connections, the absence of unnecessary wires and the quality of the contacts by pulling them with your hand. After that, power is supplied to each group in turn. RCD testing is performed by pressing the button and checking that there is no power supply in the corresponding group. If no problems are identified or after they have been eliminated and re-checked, all removed parts are returned to their place and the voltage is turned on at full load.

Correct installation and selection of appropriate components guarantees trouble-free operation of the residential energy system. Not only comfortable living depends on this, but also the safety of health, and even a person's life.