Three-phase distribution board diagram

Video tutorials on installation

If, after reading the information provided, you still do not fully understand how to correctly assemble a three-phase panel, we recommend watching videos that clearly demonstrate the assembly procedure:
That’s all I wanted to tell you about how to assemble a 380V electricity metering panel with your own hands. As you can see, the connection can only be made if you have certain skills, because... When assembling, you need to take into account many nuances, such as uniform load distribution and the correct choice of machine rating.

We also recommend reading:

380 I spend to connect a 9 kW water heater for heating a private house! I draw only one 220V line from the meter because... It is not possible to change all the wiring in the house in order to evenly distribute the load on all 3 lines! Will there be a large “load unevenness” when turning on the refrigerator and kettle and how will this affect the voltage in the house?

Some useful tips for assembling a shield

When assembling an electrical panel, it is necessary to use only high-quality and reliable electrical products

You should not pay attention to cheaper Chinese analogues; personal safety is much more important

To connect wires to machines, it is best to use special lugs for crimping. Of course, then you will have to purchase pliers with which crimping is performed, but their cost is not too high.

The use of insulating tape is no longer relevant; many electricians use exclusively heat-shrinkable tubing. This consumable is convenient and reliable, and it is not necessary to purchase a hair dryer; you can use an ordinary lighter.

For ease of use, all elements of the electrical cabinet must be marked. Only then will it be possible to quickly and easily turn off the voltage in a certain room. You can make notes on the body of the device or make small signs and attach them to the product with tape.

The difference between the shields

In stores you will see a wide range of prices for models of electrical panels that are similar in appearance. You will have a desire to save money and buy a cheaper electrical panel. Thanks to the large number of Chinese manufacturers, the quality of the shield can be very low. To reduce the cost, they use cheaper materials that are unsafe in composition and have fire protection.

When used in an apartment or private house, as a rule, the electrical panel is not exposed to precipitation and temperature changes. When installing an electrical panel in unheated rooms or outdoors, the electrical panel can quickly lose its presentation. If low-quality metal is used, the body will be covered with rust outside and inside. The case will lose its seal, the DIN rail will rust from condensation. Circuit breakers and RCDs cannot be operated in such conditions.

Low-quality plastic can crack due to temperature changes and exposure to the sun, and the seal of the electrical panel is lost. If a low-quality rubber or silicone seal is installed in a sealed IP68 electrical panel, it will lose its elasticity over time. As a result, it will not protect against moisture getting inside.

Examples of how to choose the right RCD based on rated current:

Often, some designers do, for some unknown reason, calculations of loads for houses and apartments, after which on the switchboard diagram they simply mathematically distribute the circuit breakers into phases, etc., I don’t understand why this is necessary, because in everyday life it is difficult to achieve a clear distribution of the load among the phases.

A simple example, today you are ironing things in the kitchen, as a result, the phase from which the sockets are connected received a load of + 2 kW, and tomorrow you are ironing in the Living Room, which is from a different phase - as a result, 2 kW went from one phase, and appeared on the other.

Of course, this does not mean that now you need to connect the washing machine, dishwasher, and water heating boiler to one phase. Large consumers need to be distributed as evenly as possible across phases, but there is definitely no need to count the power of light bulbs, television sets, and computers.

Thank you for your attention. I'm waiting for comments, criticism, suggestions.

Features of the electrical panel

An electrical panel with automatic devices is a box made of plastic or metal in which electrical appliances are placed. The following must be established:

main switch;
electricity consumption meter.

The input machine, as well as the meter, must be sealed. In addition to the listed devices, the distribution board is equipped with circuit breakers - they protect the home network.

Depending on the mounting method, distribution boards are divided into:

Invoices. The advantage is ease of installation.
Built-in. Requires the creation of a niche in the wall. The positive side is saving space in the room.

Types of inclusions and their features

Depending on the method of switching the windings of current transformers, three-phase meters installed in electrical networks are connected according to the following schemes:

direct connection;
indirect inclusion;
semi-indirect connection.

Direct inclusion is called direct inclusion, and to understand the differences between the second and third types, it is necessary to take into account the scope of their application. Purely indirect connection is the open installation of current transformers (CTs) on high-voltage power cables of a three-phase line (6-10 kV). This method is found only at power substations and at large industrial enterprises with their own power distribution networks. In domestic conditions, this type of connection of transformers is not used.

Distribution board with single-phase load

The simplest wiring diagram for a house or cottage will be with a single-phase load. It is enough to analyze the installed load and distribute it equally among the phases. In this case, there will be no phase imbalance in the network.

The permitted power for a private house at a voltage of 380 V is 15 kW, in this case a 15 kW distribution board diagram is proposed in the design documentation.

However, these are only recommendations, and the owner distributes the connection to consumers at his own discretion. A five-core cable is laid from the input box to the distribution board.

In addition to the phase wires, a neutral and ground wire are installed. The panel is installed using colored wires with a cross-section of at least 4 mm. According to the PEU, the neutral wire must be blue or cyan, and the ground wire must be yellow-green.

Phase wires can have any other colors. A 380 V switchboard in a private house when connecting a single-phase load turns out to be quite simple, and the switchboard is small in size. In which single-phase circuit breakers and RCD protection devices are mounted.

A distributed load is connected to the machines. It is not recommended to connect only lighting to one machine or only sockets. The load must be distributed evenly to avoid phase imbalance. A Din-rail is mounted in the panel body, on which the machines are mounted. The neutral and ground bus are mounted below. Such electrical distribution boards are installed for a small country house if three-phase voltage is supplied to the country house.

In this case, the load is connected to the automatic circuit breakers according to the following diagram:

The boiler and pumps are connected via a machine to the first phase;
Sockets and lights in the kitchen to the second;
Lights and sockets in the hall to the third.

In this case, the load will be distributed relatively evenly across the phases. Such assemblies are very convenient in terms of triggering the machine. When an emergency shutdown occurs, it is immediately clear where the malfunction occurred.

Installation of a shield for a suburban building

Using self-tapping screws, we install the Din rails on which all the equipment will be attached. They must be 35 mm in size.
We begin to install the equipment according to a pre-made diagram and calculations, install automatic machines, RCDs and two separate buses to which ground and zero are connected, and install a metering device.
We connect the phase wires and connect the machines using a special bus. According to the general rules for connecting such devices, the input should be at the top and the output at the bottom.
We install protective covers and sign all machines for convenience.
Then we connect them with a special comb or make jumpers from wire. If you are going to use a comb, then remember that the cross-section of its core must be at least 10 mm/sq.
We run wires from consumers into the machines.

Learn from this video how to properly assemble a 220 V electrical panel in a private house:
From the following video you will learn how to make a 380 V three-phase electrical panel in a private house:

After you have assembled the shield, without closing it, turn it on for a few hours, and then check the temperature of all elements. Do not allow the insulation to melt, otherwise a short circuit will occur in the future.

With a careful sequential approach and compliance with electrical safety rules, anyone can assemble an ASU on their own, although they will have to tinker. Having completed the installation, all you have to do is wait for representatives of the electrical network company, who will check your circuit and arrange the connection.

Single-branch rope slings 1SK are used at temperatures up to 100°C. They are considered reliable and durable slings that are resistant to dynamic loads. The best way to choose and order a 1SK sling is at bsts.ru

Assembly order

After receiving permission to connect to three phases and technical conditions, we will begin to independently assemble the shield. The input will be mounted in a sealed box, which must be assembled on the outer wall of a private house or pole. It contains a three-phase meter and a circuit breaker, as shown in the photo below:

Near the input we organize a grounding device, according to the rules. The input electricity metering panel will be sealed and there will be no free access to it. Therefore, the first thing you need to do is assemble a three-phase distribution panel yourself, distributing consumers as you wish.

A 5-core cable L1 is connected from the input box to the electrical distribution panel; L2; L3; N; PE, or 4-wire L1; L2; L3; N provided that the TN-CS grounding scheme is used or another grounding device is organized near the panel.

To connect three-phase home equipment, you will need to assemble a shield according to the following diagram:

The assembly of a 380-volt metering board is carried out with a stranded wire, with a cross-section of at least 4 mm and colored insulation. Recommended colors - L1 red, L2 white, L3 black, N blue, PE yellow-green. To correctly assemble a three-phase panel, you need to carefully look at the protective devices on which phase marks are marked for connecting the wires. This diagram shows four-pole RCD protective devices with an additional N terminal; in conventional machines this terminal may not be present. One by one, we begin to connect the devices installed in the panel on the DIN rail, measure the wire from terminal L1 to terminal L1 of the next device, with a margin of 30%, for ease of installation and operation.

We carry out this operation with all terminals, but keep in mind that it is not recommended to cut the sections in advance, because during the assembly process you will notice that the length of section L1 is much shorter than the mounting section L3. It’s even better to assemble the shield using a three-phase mounting bus, which will save space and minimize the chances of getting something mixed up. We separately install the zero bus and the PE bus, which we must connect to the housing of the electricity metering panel.

If you don’t have powerful equipment in your apartment or house, you need to assemble a 380V panel in such a way that each phase is evenly loaded with single-phase consumers. You can see an example of such an assembly of a three-phase electrical panel in a private house below:

In this electrical panel diagram, the phases are distributed to a separate load, through single-pole circuit breakers and differential switches. L1, L2 and L3 are evenly loaded by consumers, according to the previously calculated expected load.

It is not recommended to do this - one phase for sockets, another for lighting, a third for any other needs, because

it is important to distribute the load between L1, L2, L3. If one of the phases is overloaded, the voltage drops on it, while at the same time the voltage rises on the free ones

This phenomenon can often be observed in the winter, in the residential sector. If your neighbor in the phase turned on a powerful consumer, the lighting lamps in your house began to glow dimly, and the refrigerator began to hum strainedly. Know this is a drawdown in your phase. And at the same time, other neighbors’ lamps, powered from other phases, begin to glow brightly and explode, equipment burns out, and a fire may even break out.

As for the three-phase load, such a distortion will be fatal for it. To prevent this from happening, when you decide to assemble a shield, additionally install a phase and voltage control relay for a three-phase network. For a single-phase network, connect a voltage relay. You can check the load distribution using a multimeter with a current clamp, which is shown in the photo below.

Well, the last option for assembling a 380-volt electricity metering panel is mixed, when the home electrical network contains both three-phase and single-phase electricity consumers. In this case, you need to assemble the electrical panel as follows:

Features of a three-phase network

The first and most important thing to understand is that three-phase and single-phase equipment can be connected to a 380 V network. The difference is that three-phase is connected immediately to three phases and a neutral, and single-phase is connected to one of the phases and neutral. This connection - to one of the phases and the neutral - gives 220 V.

Do not think that the presence of three-phase equipment is mandatory. Not at all. Simply, when connecting powerful equipment to three phases, its load is distributed equally between all three phases. This means that you can use wires of a smaller cross-section and machines of lower ratings (but the wires are four/five wire, and the machine is three or four pole).

Example of a 380 V network with and without three-phase load

The peculiarity of the 380 V power supply is that there are three phases and the power allocated to you is divided equally into all three phases. If you are allocated 18 kW, each phase should have 6 kW. In this case, a three-pole or four-pole circuit breaker is installed, which will turn off the power supply completely if the load on one of the phases is exceeded. The machine has some time delay, but it is very small, so you will have to carefully calculate the distribution of the load across the phases, otherwise the light will constantly turn off due to overloads. This is the so-called “phase imbalance”, which interferes with normal life.

Electrical 380V electricity metering panel for a private house with a 220V socket

In this electrical panel diagram, there is additionally a modular 220V socket (number 7) with an individual protection device - difavtomat (number 8), which combines a circuit breaker and a residual current device. The rating of the RCD must be higher than that of the circuit breaker, for example 40A, leakage current 100 or 300 mA.

Electrical metering panel 380V, with modular socket and automatic circuit breaker, TT grounding

Following this example, where the outlet is protected by a residual current circuit breaker, you can install any other modular equipment, contactors, transformers, etc. to the electricity metering panel, if necessary.

Let me note again that under each diagram there are links, by clicking on which you can read the details, find out the equipment used, and ask questions.

Otherwise, here are the main options that are used when connecting private houses and garden houses to the power grid. And most importantly, such electrical panels are successfully accepted by regulatory authorities and put into operation.

Protection against electric shock

To protect a person from the action of current in case of unexpected contact with a bare conductor and the body of an electrical appliance, a residual current device (RCD) is installed in the panel. If you simultaneously touch a phase wire and a grounded conductive body, the power supply is turned off. For an apartment, the operating current is selected at 30 mA. It is not dangerous to humans, although it causes unpleasant pain. It does not work due to a short circuit. Therefore, an automatic circuit breaker must be connected along with it in the electrical circuit. If you use a differential circuit breaker, it performs the function of both devices, triggering not only a short circuit, but also a current leak.

Wet rooms and powerful consumers are supplied with separate RCDs or automatic circuit breakers. In a humid environment in wooden structures, even a current of 30 mA can cause a fire. In such areas, wiring requires special attention and protection.

A private house

A private house can have either a single-phase or three-phase electrical network. In the first case, the electrical installation diagram will be similar to the project for power supply of a one-room apartment. The simplest option for connecting a panel for a residential building will look like this:

In this diagram of a 220 V private house distribution board, there is a two-pole switch at the input, then an electric meter is connected, after it there is an RCD and a group of single-pole circuit breakers. Everything is quite simple and at the same time according to GOST. If a three-phase network is connected to your site, then the circuit diagram for assembling the panel will look different. Consumers from outbuildings - a garage, utility room or even a bathhouse - can already be added to it. The shield, of course, will be large and with many branches, so for the example we found a fairly suitable option.

Distribution board diagram of a private house for 380 V, using an RCD:

I would like to add a small description to this electrical circuit:

A separate line is allocated for the garage power supply, protected by a residual current device. The remaining two machines are installed on a group of sockets and garage lighting.
If there are three-phase electricity consumers in the house, it is better to connect them through a three-phase machine and a four-pole RCD, as shown in the example above. If there are no three-phase electrical appliances, you can use the project provided below.

The last 2 380 Volt distribution board schemes can be used not only to power an individual residential building, but also to power a spacious country cottage! We also recommend checking out the article on how to install electrical wiring in your home.

Hello. I want to install an electrician in a country house. On the pole there is a switchboard with a sealed 25 A machine, then a brush and again a 25 A machine. I want to install light in the house and assemble the panel. But now I don’t know what machines and RCDs to install at the entrance in the panel in the house. You have a 40 A automatic machine and a 40 A and 30 ma RCD. How will this fit with my 25A machines. And which wire to use, VVG 3x4 or 3x6?

Hello! It makes no sense to install machines in a house with a rating of more than 25 amperes; the VVG 3*4 cable has a good supply, so install it.

On one of your diagrams, after the meter there is an ouzo-d. At 20 amps. If I understand correctly, D is an ouzo category. This category is used for factories, workshops, etc. It is not recommended for apartments. since this category. Designed for high current loads at peak moment, that is. When starting engines. Until they work normally. Since when starting the engine consumes several times more current than during its normal operation

Load distribution algorithm across three phases

As already mentioned, it is necessary to collect the entire single-phase load and distribute it evenly between the phases. Moreover, the trick is to select everything so that powerful devices connected to one phase do not cause an overload shutdown. This is possible if the total power of the operating devices is no more than the nominal value, or if these devices do not operate simultaneously.

A 380 V apartment panel may not be very large

General principles of load grouping for automatic machines

The most reliable and easy-to-maintain scheme is when for each group of consumers or powerful device there is a separate machine, and together with it an RCD. But such a scheme, firstly, is expensive, and secondly, it simply requires a huge cabinet, which is also not cheap. Therefore, they try to connect several lines to one machine, but they must be combined following a certain logic. Otherwise, it will be very difficult to figure out what’s what when the machine is triggered. You should adhere to the following rules:

Connect sockets and lighting in one room through different machines. In this case, if there are problems in one of the groups, the room will not be completely de-energized.
“Wet” rooms - bath, kitchen, bathhouse - should not be grouped with “dry” ones. Firstly, in rooms with increased danger, machines should have different parameters, and secondly, it is in wet rooms that problems usually arise.
Street lighting and street sockets generally should be separate - on separate machines. Outbuildings can be connected to them.
The power supply for the gate drive and security lighting are also separate machines.
Separate power lines and separate circuit breakers and RCDs are installed on both powerful household appliances (electric stoves and electric ovens) and those that use water. As a last resort, you can combine, say, a washing machine and a dishwasher. You can also combine instantaneous and storage water heaters into one group, but on the condition that they will not turn on at the same time, since they are highly likely to trigger an overload shutdown. Moreover, they can be connected to one machine only if they are installed in the same room, otherwise you will not understand anything if damaged.

To make it easier to form groups, make a list of lines and the load on them. The room, line name and power of the connected load must be indicated. Looking at this table, following the rules described above, you assemble groups. At the same time, you must also ensure that the load is distributed more or less evenly.

Checking groups

After you have sketched out the groups on paper, check them. Sit down and think about what will happen if each of the machines works, how catastrophic the consequences will be for each room.

You can assemble a 380 V switchboard for a private home with your own hands, but you must first figure out how to distribute the load

For example, if in a two-story cottage you connect all the sockets of the first floor and the lighting of the second to one machine, and the lighting of the first, the sockets of the second to another, and the equipment to the third, then when any of the machines is triggered the situation will be terrible.

This is how we lose situations with each machine being turned off. It is advisable that there be either working sockets in the room or that they be in the adjacent one. Then, if necessary, it will be possible to connect equipment and lighting.

https://youtube.com/watch?v=jaB-iPXHZFs

Selection of electrical installation equipment

Before starting installation, you need to buy the electrical panel itself and all the electrical installations and devices that will make up its contents. It should be taken into account that each item occupies a certain number of mounting spaces on a DIN rail - a metal strip 3.5 cm wide. One or several DIN rails can be located in one box.

One “mounting point” includes a section on the profile 1.75 cm long - a module. The passport of the electrical panel must indicate how many modules it is designed for.

Three devices are fixed on one DIN rail: the first two occupy 3 modules each, the third – one module. It is not recommended to leave spaces between adjacent devices to save space.

Before choosing a shield, you should add up the number of all modules, and then add to the resulting sum several places that may be useful in the future. As an example, let’s calculate which box is needed for a 1-room apartment.

Using the diagram, we determine how many modules each device occupies: 4-pole input circuit breaker - 4 spaces, counter - 6, RCBO - 2 x 2, circuit breakers - 4. The result is 18 modules

For 18-20 seats, an electrical panel with 24 modules is suitable. But if the apartment is large, and in the future you plan to purchase new equipment, install a heated floor, or make repairs with replacement wiring, then it is better to purchase a box with 36 seats.

If you want to simplify further work, maximize network protection, and make the arrangement of modules convenient, try to choose a panel with a complete set, and this is:

removable frame with DIN rails;
entry holes and holders for fastening cables;
two tires, working and protective zero - with stands and installation sites;
set of fastenings for installation;
organizers for wires.

Shields can be metal or plastic, built-in or mounted.

Let's look at how they differ fundamentally.

Experienced electricians recommend working with one shop. The advantages of purchasing from a large supplier are a large assortment of goods and a guarantee of receiving original products and not counterfeits. Therefore, it is better to purchase both the shield and the rest of the electrical installation products in one place.

In addition to the metering device and protective devices, you will need:

combs for several poles with end caps - to connect modules to each other, simplify installation and save space;
2-3 meters of PV1 wire with a cross-section similar to the input cable and color-coded insulation;
zero busbars or cross-modules for group RCDs;
clamps and ties for organizing conductors;
limiters for DIN rails;
plugs for masking empty spaces.

If financial capabilities allow, then it is better to select equipment from one trusted manufacturer - Hager, ABB, Legrand, Schneider Electric. Devices of the same brand are easier to install, and the shield will look much more aesthetically pleasing.

Single-phase and three-phase connection

There are many technical differences between single- and three-phase connections. For example, a three-phase connection is made using four or five wires. Of these, three are phase, through which current is supplied, and the remaining two are the neutral wire and grounding. In some cases, one common wire is used for neutral and ground.

When connecting using a single-phase circuit, two or three wires are used. This corresponds to phase zero and grounding. Using two wires means that neutral and ground are on a single conductor. Knowing the number of phases in advance, you can make calculations of the permissible power and determine the amount of electrical equipment that can be simultaneously connected to the network on each line.

Read also: How to connect a digital television set-top box to a TV

In the case of a single-phase connection, all the supplied voltage is concentrated on one line, which often leads to overloads. The thickness of the wires on the internal lines of a home network is much higher than those used in a three-phase circuit. This is due to the higher load that falls on only one line. Taking into account all of the above factors, when installing power supply for a private home, preference is most often given to three phases.

Features of the electrical panel

Often home renovations need to be combined with electrical wiring repairs. If you do it with a large margin of safety, then this may ultimately cause a fire.

If, on the contrary, you make it unbearable to loads, then the plugs on the electrical panel in a private house will have to be constantly changed. Therefore, both the shield and the wiring must be carefully calculated for the current and voltage.

What is current strength

Any electrical appliance has an indicator indicating current and power consumption. If there are no current values on it, but only power consumption and voltage, then you need to divide the power by the voltage value.

When calculating the electrical panel in a private house, it is necessary to take into account the current strength. The maximum current value in an apartment is determined as the sum of the power consumption of all switched on devices, divided by a voltage of 220 Volts. If the wiring is designed for low current, then with a small load they can burn out.

It is necessary to calculate not the nominal, but the peak load, because in any apartment sometimes a vacuum cleaner or iron is turned on. So, for example, if a computer of 400 W, a lamp of 100 W, a table lamp of 75 W, a TV of 150 W, as well as a “stray load” of a heater of 2 kW, a vacuum cleaner of 1.8 kW, are constantly turned on in a room, then the peak consumption of the room will be 5.5 kW or 25 amperes.

What is the shield for?

Many home owners do not know what an electrical panel is for. Its main purpose is to protect against network overloads that can cause a fire.

If the wiring has a low cross-section, then under heavy loads it may not withstand and catch fire. If there are oversized circuit breakers on the electrical panel, then if high-power appliances are turned on in the house for a long time, the sockets may burn out.

If you increase the cross-section of the wiring, then the apartment, in fact, will also be left without protection: the machines may not respond to high load parameters. In a word, the shield must have optimally selected plugs, which must match both the power consumption and the cross-section of the wiring.

What types of wires are there?

Standard wires are connected to the panel. Copper wiring has four standard types of cross-section - from 1.5 mm 2 to 6 mm 2. The permissible current strength of the thinnest wire is 15 amperes, the thickest is 34 amperes. The aluminum wire must have a much larger cross-section. It is not recommended to use soft cables, as there may be problems with the safety of the wiring.

Be careful: shields in a private house and sockets are not suitable for wires smaller than one and a half square meters. mm. There is also no need to take machines smaller than 10 amperes.

What needs to be installed in the panel

The panel must provide for the division of wiring into several lines. If there is one line in the house, then in the event of an accident the entire house will be de-energized. By dividing the wiring into several parts, it will be easier to determine the location of the accident.

Several circuit breakers need to be installed in an electrical panel in a private home. For example, for each room you need to install a separate machine. Ideally, there would also be an automatic for lighting. The machines receive power through one large machine. This is necessary so that you can quickly turn off the power to the entire room. The machine is numbered in position from left to right.

Installation and replacement of the shield

You can install the electrical panel yourself. The simplest procedure in this case is to replace the machines.

The meter can be seen on the panel, as well as a batch switch and automatic machines. The batch switch looks like a device with four contacts and a rotary handle. From the main electrical wires, phase and zero come to the panel.

Before replacing machines, you need to check their nominal value and buy the same one. In no case should you install a machine with a larger rating, as this leads to accidents if many powerful devices are turned on simultaneously on one machine.

Replacing the machines is done with the package switch completely turned off. However, you need to be careful, otherwise if you move incorrectly you can be left without light. Remember that you cannot repair or install a packet switch yourself. To do this, you need to call a qualified electrician.

If a short circuit occurs when installing machines, you need to check the condition of the wire insulation and, if necessary, replace it with electrical tape.

Plastic enclosures for the electrical panel can be purchased at the store. As a rule, they have a ready-made DIN rail. The product package also includes grounding pads and a zero. You should not buy cases with plastic slats, as they break and do not provide the necessary safety.

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Selective RCD. Shield diagram

Next in the switchboard circuit after the input circuit breaker, there may be a selective RCD. Why I wrote maybe, because according to the mind, a selective RCD should be located in the metering panel, i.e. at the beginning of the line. But it often happens that it is impossible to put it in the metering panel, because... either there is not enough space in the shield on the pole, or the shield is sealed, or the customer simply does not want to place an expensive item outside the house.

Selective RCDs are often installed in private houses ; in apartments there is no particular need for this. If you decide to install a selective RCD, then it is more correct to choose its rating of 63A , even though the rating of the input circuit breaker, for example, is only 25A. I have not seen incoming circuit breakers for private housing above 63A, and the RCD at 63A will not have to be changed when the power increases, i.e. if you decide to replace the 25A input circuit breaker with a 50A one, you will not have to change the selective RCD, because 50A

The selective fire RCD setting for a house or apartment can be selected as 100 or 300 mA.

Assembly diagram of a distribution panel in an apartment and a private house

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In order for the electrical wiring to be safe, easy to maintain, and also able to withstand the load from all electrical appliances in the home, it is necessary to correctly approach the design of the distribution board wiring diagram. This project should indicate the entire hierarchy of circuit breakers and RCDs, right down to the socket group. In addition, all protective automatic devices must indicate the rating, as well as the protection class. Next, we will provide readers of the Sam Electric website with visual diagrams of the switchboard in a private house, apartment and cottage.

So, if the apartment is of old construction and, moreover, one-room (for example, Khrushchev), then the electrical wiring project will look like this:

As you can see, in this wiring diagram for the distribution panel there is no PE bus, because In old Khrushchev buildings there is no grounding. As for the elements of the electrical circuit, it consists of a two-pole circuit breaker, an electricity meter (Mercury 201), an RCD and group “packets”. One machine serves the lighting group, the second - sockets, and the third - the washing machine. If you have a ground loop, then the electrical diagram for assembling the distribution board in the apartment will look like this:

The dotted line (1) indicates the housing of the distribution board, (2) and (3) this is the neutral and grounding bus. The fourth element of the project is the comb that connects the circuit breakers. (5) - a single-phase RCD of 40 Amperes and a leakage current of 30 mA, and (6) - group circuit breakers (3 of 16 Amperes and 1 of 25, for connecting a hob). A single-pole circuit breaker with a rating of 40 Amps is installed at the input. The lowest row of the electrical circuit consists of residential consumers - a group of lighting, sockets and powerful electrical appliances (in our case, stoves).

Well, there are also spacious apartments with electric heating and a group of powerful electricity consumers. In this case, the electrical circuit of the input distribution panel will be more serious and the number of circuit breakers will be no less than that of a private house. So, for your attention, the distribution board diagram for an apartment with an improved layout:

With such a number of electricity consumers, there must be a three-phase network (380V) and at the input, accordingly, a three-pole 63 Ampere circuit breaker. Otherwise, there is a 40 Ampere RCD, a group of 16 and 25 Ampere circuit breakers (depending on the purpose), and a separate residual current device for electrical wiring in the bathroom. with a leakage current of 10 mA.

Based on the provided apartment panel connection diagrams, design your own version and proceed to electrical installation work! How to assemble a switchboard with your own hands. we already told you!

Electrical panel design and elements

Electrical panel elements

For a three-phase switchboard with a power of 15 kilowatts and a consumption power of 15 kW/h, the following components will be needed:

Electricity metering device. The meter is installed in the panel immediately. Electronic models that are highly accurate and reliable are suitable for a home network. They work at several tariffs and display data on a digital display.
Electrical panel It is a box of various sizes. The outdoor version must have a DIN rail, a lock, and an inspection hole for taking readings. The optimal level of dust and moisture protection is IP 54, wall thickness is 1 mm.
Difavtomat at the input. A three-pole model connected to three phases is suitable.
RCD. Element of protection against the occurrence of dangerous potential on the device body.
Automatic type switch. In a private house, you will need a 25 A device for input, for a lighting system - 6.3 or 10 A, for a power circuit - 16 A. The power of such a switch is from 7 kilowatts.
Voltage relay. Prevents damage to household equipment due to voltage fluctuations.
Measuring devices. A voltmeter and an ammeter in one housing is an optional device.

Switchboard layout

I have already discussed in detail the basic principles of layout when designing and assembling distribution boards. In the electrical panel under consideration, the layout (i.e., the arrangement of devices inside the electrical panel itself) is adopted in a row in groups.

Enter

A load switch and a voltage control relay are installed on the first DIN rail at the input of the distribution board.

The load switch allows, if necessary, to completely de-energize the entire electrical panel for repair or maintenance work on both the switchboard and the entire apartment electrical wiring as a whole.

The ZUBR voltage control relay provides protection of the home electrical network from surges and surges in voltage in the supply network, as well as protection from zero loss.

Later, depending on financial capabilities and the purchase of equipment for a low-current network, the customer will add here both a circuit breaker for a low-current switchboard and other devices that are still being considered.

Kitchen

A group kitchen RCD is installed on the second DIN rail, and after it there are automatic switches for kitchen consumers:

— electric oven;

- kitchen sockets;

- kitchen air conditioner.

Room sockets

A group RCD of socket groups is mounted on the third DIN rail, followed by automatic switches in the rooms:

- room sockets;

— two air conditioners;

- apartment lighting.

Useful devices (devices)

Now let's look at the benefits that enhance electrical installation.

Stopper for DIN rail

A special limiter that is installed on a DIN rail and prevents axial displacement and skewing of devices mounted inside the switchboard on a DIN rail.

If a large number of modular devices are installed in a row, they usually move relative to the horizontal, which makes it difficult to install the external panel of the switchboard and disrupts its aesthetics.

The use of special limiters solves this problem and improves electrical installation standards. For more information on this, see the video at the bottom of this article.

Cross module

Cross-modules are very convenient to use when assembling distribution boards.

With their help, it is very convenient to make a branch of supply lines, especially when assembling 3-phase distribution boards, when it is necessary to distribute consumers into individual phases. The supply voltage is supplied to separate buses of the cross-module, and from them consumers are connected to the free terminals.

If you need to change something over time, you can simply make the switching inside the cross-module itself, without changing the installation inside the switchboard itself. It's very practical.

In the case of using several voltage control relays for maximum protection against voltage surges and surges in the supply network, it is also convenient to use a cross-module to connect them. I will tell you how to do this in the following materials, so subscribe to the newsletter and stay tuned for new materials on this and other topics!

Thus, the use of these four utilities when assembling distribution boards optimizes electrical installation and makes it better and more professional, provided, of course, that all rules and regulations are followed.

Watch the video

Distribution board - assembly benefits

I also recommend reading

Home electrical panel

According to Nikita, the control panel in the house will contain the following consumers and groups:
1) refrigerator up to 500W / 2.27A / 1.5mm cable / C6 automatic 2) Electric stove 2.5 kW + hood 0.5 kW + electrical appliance 1 kW = 4 kW /18.18A/2.5mm/C16 3) washing machine 2.5kW/11.36A/2.5mm/C10 4) water heater 50-80 l 2kW/9.09A/2.5mm/C10 5) Bedroom: heater 1.5 kW + 0.5 gadgets = 2 kW / 9.09 A / 2.5 mm / C10 6) children's room: heater 1.5 kW + 0.5 gadgets = 2 kW / 9.09 A / 2.5 mm / C10 7) bathroom: hair dryer 1.5 kW + heater 1 kW = 2.5 kW / 11.36 A / 2.5 mm / C10 living room: gadgets 1 kW + electrical appliance up to 1.5 kW = 2.5 kW / 11.36 A / 2.5 mm / C10 9) light around the house up to 5 amperes/1.5mm/C6 10) Reserve the oven, I’m not putting it on yet, but we’re counting on it right away. 3kW/13.63A

The total load is obtained if everything is turned on at once: 22.5 kW and 100 Amperes.

My answer, some aspects of electrical panel building:

There are no powerful pumps or sawmills in the house. In addition, I am sure that in rural areas the short-circuit current is small. Therefore, I insist on installing automatic machines with a type B release characteristic. In short, AVs with a time-current characteristic “B” operate much more reliably where there is a large distance to the transformer substation and the electrical networks are worn out. As a result, an electrical installation with “B” will be safer than with “C”.

The maximum current will not reach 100 A, since it will be limited to AB 32 A. As I said, this is quite enough for an ordinary house, since everything will never turn on at once. Therefore, all cables with a cross-section of 2.5 mm2 can be protected by AB at 16 A - such a machine will perfectly protect the cable during overload and short circuit, and there is no need to limit power by group.

Installing an RCD is more preferable than a difavtomat, since it allows you to create more flexible systems. For example, it is very difficult to find a differential automatic machine with a time-current characteristic “B”. And it is much more difficult to determine the reason for the operation of the differential circuit breaker than in the case of using the RCD + AB combination.

If possible, it is better to buy with the “A” type of differential current (if there are a lot of electronics in the house, “A” provides greater security than the cheaper “AC” type).

There is no need to install an RCD for lighting. On the refrigerator too - it will have to be hung on a separate differential circuit breaker or RCD, because if there are other problems on this RCD, the refrigerator will be left without power. Therefore, if the new refrigerator is powered through a separate AV, and there are no open grounded objects nearby, it is better not to install an RCD.

At the entrance to the home distribution board, you need to install an introductory 2p automatic machine, despite the fact that there is an automatic machine for the house in the main switchboard. This is necessary for convenience - it is convenient to run the wires, and it is convenient, if necessary, to instantly turn off the power to the entire house. After all, you need to run to the pole, and the main switchboard may be locked (this is the stupid requirement of local electricians).

A voltage relay is another component to protect household consumers. If the voltage goes outside the limits (for example, 175...245 V), the house will lose power. I recommend installing voltage relays in several articles on the blog. Plus voltage relays - almost all of them show the current voltage value, and some (this is especially convenient) - current consumption and power.

The rated operating current of the RCD and voltage relay in this case must be no less than the rated current of the input circuit breaker - 32 A. Better - more.

As a result, the scheme will be like this:

Home electrical panel diagram with voltage relay and RCD

Loads:

L1 – Electric stove, kitchen sockets,
L2 – Washing machine,
L3 – Water heater,
L4 – Bedroom,
L5 – Children’s room,
L6 – Bathroom,
L7 – Living room,
L8 – Oven,
L9 – Refrigerator,
L10 – Home lighting.

Description of the shield device.

The PE, L and N wires come from the ASU via a three-core cable. The PE protective grounding wire comes to the PE bus, to which the protective conductors of all consumers are connected. All new shields usually already have this tire. If the shield is metal, it is also grounded.

The phase and neutral L and N pass through a two-pole switch on the voltage relay (I wrote about this above). After the voltage relay, the phase and neutral are supplied to the cross-module X0, which is needed exclusively for convenient, understandable and high-quality installation. The cross-module contains 2 buses, each of which must contain at least 5 screw terminals. In order not to clutter the diagram with wires, the connection is indicated by one wire; in fact, the connection will be separate wires from X0 to QF1, QF2, QF3, QF12+QF13.

RCD QF1 “works” in two groups – L1 and L2. Three groups are connected to the RCDs QF2 and QF3. For ease of installation, I suggest using local neutral buses, shown in the upper right corner of the diagram.

Grounding and PEN separation

This is the situation regarding grounding. I was thinking about making a separation of the PEN conductor and the TN-CS system in the main switchboard.

The installation of VLI (Air Line Isolated. That is, a SIP line) was carried out by contractors. And I have doubts about the quality of their work. That's why I made the TT system. I did not split the PEN.

The ground loop is connected to the PE bus, but the incoming neutral is not connected to my ground. I drove in 4 pins (pipe with a diameter of 32 mm, wall thickness 4 mm, 2.5 meters each.).

I provide electrician services in my city and before I recommend anything to any of my clients or install it in a panel, I first test it at home. It’s the same in this case - if EKF products serve me without any complaints until spring, I will supply them to my clients as well.

That's all for now. We wish Alexey good luck!

Let me remind you that the article is competitive and takes part in voting from November 20 to December 20, 2022. To find out how things are going with the Competition right now, follow the link.

Simplified diagram of an apartment panel

Scheme No. 1
This scheme is suitable for small one or two room apartments. Where the total length of all wires and cables does not exceed 300-400m.

There is a load switch at the input, not a circuit breaker. If you already have protection installed on the floor switchboard, after or before the meter (check this before assembling this circuit), then it is not necessary to install a machine at the input. The better the load switch from the machine can be found in the article Modular load switch or incoming machine.

The rated current of the input device for apartments with electric stoves and single-phase load should be from 40A and above. Below are group cables feeding certain groups, indicating the cable brand and its cross-section depending on the load. Outgoing lighting circuits made with a 1.5mm2 cable are protected by a 10A circuit breaker, socket groups with a cross section of 2.5mm2 are protected by 16A.

The bathroom is connected to the differential machine, i.e. sockets, lighting and all consumers in the bathroom are combined into one group. Moreover, the leakage current on the diff is selected to be 10 mA.

Some electricians set it to 30mA, citing possible false alarms. There is no specific prohibition in the rules; it stipulates that this protection should not exceed 30 mA. Why it is still better to set it to 10mA can be understood by familiarizing yourself with how a current of a certain magnitude affects your body:

True, in order to purchase 10mA differential automatics in stores, you will most likely have to place an order. Basically, devices with a leakage current of 30 mA predominate on the free market.

The hob and oven are powered in separate groups, implying that these are two different consumers. If you have an electric stove, that is, when the hob and oven are combined, you need to change the power cable and circuit breaker:

Scheme No. 2

If you are concerned about power outages and want to protect your equipment from power surges, then you can slightly increase the cost of the circuit by adding a voltage relay to the input. Here is a schematic representation of a relay of the UZM-51M brand, as the easiest to connect (input-phase + zero and output-phase + zero).

Scheme No. 3

The advantages of these schemes:

inexpensive
the best option for small apartments
easy to install and connect

The big disadvantage of the circuit is that if there is a current leak in lines other than the bathroom, the protection will not work.

This circuit can be improved by placing an RCD at the input. Before doing this, make sure that a circuit breaker is installed in the floor panel where your meter is located, since it is prohibited to install an RCD without a circuit breaker. If there is already an RCD or automatic circuit breaker there, then it makes no sense to duplicate the protection. The circuit with the RCD at the input will be like this:

Scheme No. 4

One caveat - if your total cable consumption in the wiring of an apartment is 400 m or more, then false alarms of the input RCD are possible due to total current leaks. Here it is already advisable to apply the RCD to separate groups, removing the introductory one from the apartment panel diagram.

Purpose of equipment and importance of calculations

The main purpose of the distribution board is to protect the home electrical network from overloads, and the premises itself from fire

It is important to understand here that the design and calculations of all parameters must be carried out with the utmost care. For example, if the cross-section of the wiring is incorrectly calculated and the installation is of insufficient size, the load on the network can cause the insulating layer to burn

The other extreme is installing too powerful machines. In this case, electrical appliances with high energy consumption may cause the sockets to burn out.

For example, if the cross-section of the wiring is incorrectly calculated and the installation is of insufficient size, the load on the network can cause the insulating layer to ignite. The other extreme is installing too powerful machines. In this case, electrical appliances with high energy consumption may cause the sockets to burn out.

Wiring with a large cross-section that is not designed for specific conditions also leaves the network defenseless. During a load surge, protective actions may not occur because the circuit breakers will not have time to respond to critical indicators in time.

Approximate diagram of electrical panel constructionSource ul-avesta.ru

Assembly of a home three-phase main switchboard

In March of this year, a 3-phase SIP was installed on my support and a metering board (ASKUE) was hung up, and I began to complete the main switchboard (main distribution board).

Anyone can buy a shield in a store, but I’m always interested in making something with my own hands. I used the housing from the LB|S 250(HS) lamp with a glass door - very convenient for monitoring the condition of the contacts. Case size W 340mm x D 520mm. Protection degree IP54.

Three-phase main switchboard with RCD and voltage relay. You can zoom in

The meter stands on a support in front of the control panel; a three-pole C 40a circuit breaker was placed in front of the meter. I ordered low-voltage equipment from an online store. Four-pole input circuit breaker C 32a, including a fire protection RCD “Contactor” with a rated current of 50A, differential current of 100mA. UHL3. Uzo fire protection. I didn’t find a selective one.

Selective RCDs are extremely rare for sale, they are made to order.

Next comes the C 32a machine on the line to the house. The house has a panel with 36 modules. In parallel with it, I installed an AB C 25a for input into the workshop; the plan will also include a couple of lines for sockets and lighting from this panel for the utility unit. Therefore, I installed the UZM-51M Voltage Control Relay from Meander UHL2. On the Voltage Control Relay the limits are set as follows: Upper limit is set to 260V, Lower limit is set to 175V.

1 A circuit breaker for socket

A display with meter readings is installed under the main switchboard:

Display Matrix for three-phase meter

Of course, the display does not show the energy consumed). This is the meter number. To be honest, the energy supply organization has not yet configured the display readings for me.

Convert Watts (W) to Amps (A).

Converting amperes to kilowatts (single-phase 220V network)

For example, let's take a single-pole circuit breaker with a rated current of 16A. Those. A current of no more than 16A should flow through the machine. In order to determine the maximum possible power that the machine can withstand, you must use the formula: P = U*I

where: P – power, W (watt);

U – voltage, V (volt);

I – current strength, A (ampere).

We substitute known values into the formula and get the following:

P = 220V*16A = 3520W

The power is obtained in watts. We convert the value into kilowatts, divide 3520W by 1000 and get 3.52kW (kilowatts). Those. the total power of all consumers that will be powered from a machine with a rating of 16A should not exceed 3.52 kW.

Converting kilowatts to amperes (single-phase 220V network)

The power of all consumers must be known:

Washing machine 2400 W, Split system 2.3 kW, microwave oven 750 W. Now we need to convert all the values into one indicator, i.e. convert kW to watts. 1 kW = 1000 W, respectively, Split system 2.3 kW * 1000 = 2300 W. Let's sum up all the values:

2400 W+2300 W+750 W=5450 W

To find the current strength, power 5450W at a network voltage of 220V, we use the power formula P = U*I. Let's transform the formula and get:

I = P/U = 5450W/220V ≈ 24.77A

We see that the rated current of the selected machine must be no less than this value.

Converting amperes to kilowatts (three-phase network 380V)

To determine the power consumption in a three-phase network, the following formula is used:

P = √3*U*I

where: P – power, W (watt);

U – voltage, V (volt);

I – current strength, A (ampere);

It is necessary to determine the power that a three-phase circuit breaker with a rated current of 32A can withstand. We substitute the known values into the formula and get:

P = √3*380V*32A ≈ 21061W

We convert watts to kilowatts by dividing 21061W by 1000 and find that the power is approximately 21kW. Those. a three-phase 32A circuit breaker can withstand a load of 21 kW

Converting kilowatts to amperes (three-phase 380V network)

The current of the machine is determined by the following expression:

I = P/(√3*U)

The power of a three-phase consumer is known, which is equal to 5 kW. The power in watts will be 5kW*1000 = 5000W. Determine the current strength:

I = 5000W/(√3*380) ≈ 7.6 A.

We see that for a consumer with a power of 5 kW, a 10 A circuit breaker is suitable.