Do-it-yourself electrical panel wiring: diagrams + step-by-step assembly instructions

As you know, repairs are akin to a small-scale natural disaster, and one of its integral components is the electrification of residential or business premises. We remember how important a role electricity plays in a home when it suddenly disappears due to an accident. Providing an apartment or private house with electricity, as a rule, includes two basic components: installation of electrical wiring and assembly of an electrical panel.

Each of these components involves the sequential implementation of a number of steps, which at first glance are quite simple, however, as practice shows, in the vast majority of cases, requiring the participation of a professional electrician. If the owner of the premises intends to independently solve the problem of supplying electricity to a house or apartment, it is necessary, at a minimum, to carefully study the hardware, that is, prepare theoretically, before assembling the electrical panel with your own hands.

Single-phase distribution board diagram - 5 different options

Today, almost no facility can do without electricity, since they need sockets for connecting electrical equipment and room lighting.
All apartments, houses, offices, garages, warehouses and so on have an extensive power supply network. To protect it, for the electrical safety of people, and to effectively manage the electrical network, it is necessary to install electrical distribution panels. They contain switching protective devices that perform all the functions listed above. The switchboard is divided into groups, which allows for convenient and independent operation of powerful household appliances. All objects are different and, accordingly, their power supply networks will also be different. Below we will look at a few simple examples, which show five options for single-phase power supply circuits for apartments and private houses.

General principles for constructing any shield diagram:

There must be an input switching device at the input. This may be a circuit breaker or a switch (load switch).
All group lines extending from the switchboard must be protected against overload and short-circuit currents.
All socket groups must have human protection from electric shock. For these purposes, residual current devices (RCDs) or automatic circuit breakers with a leakage current of 10-30 mA are installed.

Do-it-yourself electrician: Designing and assembling a single-phase switchboard for an apartment (part 1)

Introduction

Good afternoon
With this article, I decided to start a new series dedicated to how to independently carry out design and electrical installation in a new building, which, judging by the abundance of such topics in the “Electrical” section, is very relevant. As I was creating this article, I decided to first separate into separate articles how to choose a cable for internal installation and how to independently design power lines in an apartment.

So,

I believe that the desire to design and assemble a shield yourself is primarily due to the fact that it is incredibly difficult to find an adequate contractor in the field of repair services. On the one hand, the cost of services of highly qualified electricians is quite high and they usually have a waiting list of customers. Unfortunately, one cannot deny the fact that price is not always a sign of quality. On the other hand, there is an incredible number of hack performers on the market with appalling quality of work, whose goal is to quickly get money and get out of the project, and at least the grass won’t grow there:

The wiring in the picture from the topic about false electricians is made with a two-core SHVVP wire with a greatly reduced cross-section - 0.75 instead of 1.5 mm2; The insulation of connections and their installation are of appalling quality. Twists do not provide reliable contact. In the near future, this junction box has every chance of burning out along with the apartment.

It happens that “electricians” directly tell customers that they don’t know how to assemble panels and ask for tips. Or they deliberately hide it and tamper with fire-hazardous and dangerous switchboards from the point of view of the possibility of electric shock. Like, for example, another shield from the epic theme “Caution! False electricians!”:

The customer, a young woman who entrusted her repairs to hacks, unfortunately, did not know that her new apartment could burn down due to the greatly inflated ratings of the machines, the undersized cross-section of the cable cores and their generally low quality, as well as “snot” jumpers between the machines, through which the total current of the apartment flows. She also did not know that she and her family were in serious danger of electric shock due to the complete lack of differential protection (that is, against current leakage, including through the human body), especially in the bathroom. And this is not to mention the terrible performance of the shield itself.

This, unfortunately, occurs relatively often. Hence, many customers themselves try to understand this issue.

In this article I will talk about how to independently design and assemble a single-phase switchboard for an apartment, using one standard circuit. This scheme is safe, reliable and budget-friendly for most apartments.

Due to some features of the old housing stock (lack of dedicated grounding, separation of lines in the floor panel, etc.), the article will be applicable to the old housing stock with some reservations. Three-phase switchboards, switchboards for cottages, switchboards with automation, etc. are not covered in the article, however, for such shields you can use the principles and methods described in the article. In this case, I recommend creating a topic on the Electrical forum.

The article assumes that you have some basic knowledge of modular devices - for example, you know what a circuit breaker is and how it differs from an RCD. And most importantly, you are familiar with the safety rules when working with electricity (although you will not need it during design and assembly).

Initial data for design

“Three pillars” serve as the initial data for designing a shield:

Budget

First of all, you will need to understand the budget of your shield - how much are you willing to pay for materials for it? (We believe that DIY assembly will be free). No one is stopping you from considering several options and choosing the one that suits your money.

The photo shows a one-room panel with a size of 24 modules, but nevertheless having all the necessary protections and even a customizable bathroom ventilation timer. By Mastercity standards, such a shield is considered small and inexpensive.

However, for owners of apartments in the old building, where there are only three machines per three-ruble apartment, this shield will seem large.

And this is not to mention, for example, such a shield:

This photo shows a shield for a business-class apartment, where the customer planned many power and low-current lines, and also had certain requirements for the shield. Panels of this size are quite common, for example, for cottages or large apartments, where the customer has some preferences in terms of electrics and low current.

Naturally, most people do not need such large shields - this shield illustrates that if you want a lot, then you should budget accordingly.

In general, when choosing lines and modular devices in a panel, always keep your budget in mind. In my experience, it often happens that customers get carried away by the options available, but in the end they have to reconsider their decisions because the cost is beyond the budget.

I will give several dependences of price on parameters for small standard panels (of course, we do not consider complex and non-standard panels):

According to my observations, the greatest relative influence on the price of the shield is exerted by the number and type of differential protection devices, namely RCBOs (RCDs) and RCBOs (Differentials). By putting an excessive amount of VDT into a shield, you raise the price of the shield to the skies. On the other hand, you can’t do without VDTs at all - this is a critical element of your safety and the safety of your loved ones.
The manufacturer of modular devices has a strong influence on the price. When buying Siemens machines of the “industrial” series, you get excellent quality and reliability, but the price is too high; By buying Chinese machines, you take a risk, but the amphibian is very happy.
Also, within one company, there may be several series - for example, regular and “home” (cheaper). However, prices between series vary greatly. Prices depend even more strongly on the breaking capacity (measured in kiloamps) within one series - a circuit breaker with a breaking capacity of 10 kA (kiloamps) will cost significantly more than one with a 6 kA from the same series. At the same time, 4.5 kA is quite sufficient in everyday life (but many European manufacturers no longer produce circuit breakers with a breaking capacity of less than 6 kA).
The size of the shield also affects - the more din rails are required, the more the shield costs with each new rail. But when designing, you should always leave some margin for empty spaces - first of all, so that you can then route the wires inside a fairly compact panel space.

Therefore, it makes sense to choose some kind of “golden mean” based on your capabilities.

Consumer lines that will be powered from the switchboard.

A line means one or more consumers to which one power cable goes from the switchboard. The line, for example, can be kitchen sockets, which are connected either in series or in a junction box.

Power lines coming to the machines installed in the switchboard - the cables are connected directly to the output terminals of the devices.
In more complex boards, power lines come to special terminal blocks, from where they are connected to the board devices via internal wiring:

Different people have different situations - in one case, a major overhaul is being done with a complete replacement of the wiring, or repairs are being done from scratch and there is the opportunity to design the lines yourself. In another case (partial repairs or completion by hacks), the lines have already been drawn and you have to work “with what you have.”

If you are doing electrical work from scratch, please read the article “Designing power lines in an apartment.” If you are in doubt about choosing a cable brand, I hope the corresponding article on Mastercity will help you decide.

If the lines have already been made, you will need to make a list of these lines. If your work was done by dubious “masters,” it is also advisable to test the lines and check the insulation resistance with a megohmmeter.

In either of the two options, before designing the shield, you must have a list of lines ready. Ideally, this should be done in tabular form in Microsoft Excel or similar:

Having a compiled list of lines in hand, this stage can be considered closed.

Rating of the input circuit breaker (and RCD if available) and cross-section of the input cable.

The distribution board can be figuratively represented as a tree.
The opening machine in this image will be the base of the trunk. The input circuit breaker serves to protect against overcurrents in your apartment, and also plays an important role - it limits the maximum power that you can get from the riser. This machine is installed by the network company and cannot be easily replaced (at least, to replace it with a higher rating, an application to the energy supply company will be required).

If you are interested, the value of the long-term permissible power limited by the circuit breaker is calculated by the formula: P [kVA] = In [A] * 0.26, where In is the rated current of the input circuit breaker. You can exceed this power for a short time, but the input machine will turn off after some time.

When designing, you should understand that no matter how many “branches” (that is, lines) you design, a thin trunk will not allow you to grow juicy apples on them.

Also, one should not mistakenly assume that the “cross-section” of the trunk should be equal to the cross-section of the tree’s crown. That is, that supposedly the nominal value of the input (or any superior) machine should be equal to the sum of the nominal values of the lower ones. The sum of the ratings of line machines is usually several times greater than the rating of the input machine - the fact is that electrical appliances almost never operate at full capacity and at the same time.

For further design, you should understand what devices are located in your floor panel, that is, open its door. Climb inside the shield itself, remove the protective cover, etc. no need.

In addition to the machine, floor panels in modern new buildings are equipped with a fire protection RCD with a rating of 100 or 300 mA and a meter. Photo of such a typical floor panel of a new building:

The photo shows a 50 ampere input circuit breaker with characteristic C, a meter, a fire protection RCD with a rated current of 50 amperes and a differential current of 100 mA (AC type).

The most important thing here is to make sure that there is an input circuit breaker and, if there is one, find out its rating (in this case, 50 amperes). The fact is that some developers, instead of a machine, put a switch in front of the meter (it looks almost like a machine), counting on the fact that the machine will be installed in the apartment panel. As a hint, the machine is distinguished by the presence of a letter of the time-current shutdown characteristic before the nominal value (usually C), for example, C50. If you have any doubts, you can find information on the names of the devices on the Internet, or you can ask your management company.

If there is no input circuit breaker (there is a switch instead) - be sure to remember this fact and in future steps, provide an input circuit breaker in the panel.

If a fire protection RCD is installed, that’s good; if not, it’s not a big deal. In all new buildings and reconstructed risers of old houses, these RCDs are installed as required by fire safety standards.

But our designed shield will already contain more sensitive RCDs. Therefore, if you do not have a fire protection circuit in the floor panel, and the input cable is monolithic, it is not required. Please note that in private houses the situation will be slightly different; we do not consider private houses in this article.

In the old housing stock, everything is somewhat more complicated - if there was no reconstruction of the riser, then most likely a batch switch is installed at the input, then a meter, then 2-3 automatic devices (sockets, lighting and a stove, if any), the lines from which go to the apartment. If there was a reconstruction, then instead of a package, they usually install an introductory automatic device and, perhaps, a fire-fighting RCD. In this article I will not dwell in detail on the old housing stock because it is worth devoting a separate, very sad, article to this. If you have such a house and want to install an apartment panel, provide a photo of your floor panel in the comments to the article or create a topic on the forum.

ATTENTION for residents of old housing stock!!! If you see a batch switch installed in your floor switchboard, do not touch this device and urgently call an electrician from the management company to replace it with an automatic one. The fact is that it can explode when switching due to degradation of the carbolite internal insulation and subsequent internal short circuit:

(picture taken from the website avariyca.ru) By the way, in some new economy-class buildings, especially those that are delivered fully furnished, developers install 2-3 machines in the floor panel, as was done in the old building. In this case, if you decide to make a shield in an apartment, you need to re-route the input cable, which is fraught with some difficulties. But this is also a separate story that should be considered individually.

In general, according to the third point, you should have an answer to the question - is an input circuit breaker (not a switch!) installed in the floor panel, and if so, what is its rating.

Selection of architecture and basic shield design

Among the many schemes and options, I propose to consider the “classical” architecture of an RCD with automatic circuit breakers in a simple version and a version with “non-switchable” lines.
I talked about “non-disconnectable” lines in detail in the article about line design. These are those lines that remain on in case of long-term departure (vacation, etc.) - for example, a refrigerator, an aquarium, a burglar alarm, etc. These lines are grouped so that, when leaving, turning off just one switch or circuit breaker in the switchboard, you will turn off power to the entire apartment, except for these lines. And, accordingly, upon arrival, turn it back on. Naturally, when an overcurrent appears in the line or at the user’s request, they are turned off, which is why the word “non-switchable” is indicated in quotation marks.

If your shield is small or you are not too lazy to click the machines, you can do without any switches and turn off all the machines when leaving, except for a few of these lines. In this case, choose the normal option.

In the optimal option, which is most often recommended on the forum (but it is far from the cheapest), there are two lines in each room - lighting for a given room and sockets for a given room; a dedicated line is designed for each powerful electrical appliance. In addition, one or two “non-switchable” lines are made - for example, a refrigerator, an aquarium. If there is a leakage protection system, it is placed on an additional “non-switchable line”.

So, here is a classic circuit for an RCD with automatic machines:

The panel consists of several RCDs (usually from two to four), between which the line circuit breakers are distributed. This scheme has many advantages:

Absolutely all lines have differential protection. Regulatory requirements do not require differential protection on lighting lines and stationary consumers (for example, air conditioning), but it is a good tradition to protect such lines as well.
A very low price compared to the circuit on difavtomats, while the level of reliability and protection is somewhat higher because, firstly. An RCD is traditionally considered a more reliable device than a differential automatic device, and secondly, a differential automatic device is very expensive, and in a circuit with differentials they are not installed on all lines.
When the RCD is switched off due to current leakage, only part of the lines will be switched off. With proper distribution of lines through the RCD, such a disconnection will cause minimal inconvenience to residents.
This circuit is incredibly easy to assemble and does not require special skills or tools.

There is a variation of the circuit for those who are afraid of tripping the RCD when the air conditioner is operating due to leaks in the terminal block of the external unit (although I have not seen this during high-quality installation of the air conditioner). There is also no consensus on this issue on the forum (as well as on many others):

And finally, an option with “non-disconnectable lines” (usually there is only one such line, but the general case is shown):

An input machine is necessary (I emphasize this word) only if an input machine is not installed in the floor entrance, but instead a switch or batch switch is installed. If there is a machine gun in the floor panel, you can safely remove it from the diagram.

Next, you should decide on the number of RCDs in the panel.

The number of RCDs is determined primarily by the thickness of your wallet, since this is a rather expensive device (the cost of a single-phase device as of 2016 ranges from 1,500 to 3,500 rubles, depending on the manufacturer and type). In fact, to ensure safety, one RCD is enough - if the wiring in the house is done more or less efficiently, then there will be no false alarms at all. Increasing the number of RCDs does not increase safety, but greatly increases comfort - when the RCD is turned off due to a leak, fewer lines will be switched off at the same time (the RCD turns off all downstream lines). I think the reasonable number of RCDs for a one-room apartment “without frills” is two, for a two-room and three-room apartment “without frills” - 3, the most optimal is the same number plus one. Large quantities are already overkill, but it can be justified if there are special requirements for the shield or a large number of lines.

Important! The rating of the RCD must be no less than the rating of the superior machine.

Many beginners make the mistake of installing RCDs of different ratings depending on the number and rating of machines connected to them - but this is not the right approach. If the input circuit breaker is rated at 40 amperes, then all RCDs should be rated at 40 amperes; if they are 50, then all RCDs should be rated at 63 amperes, since among the manufacturers known to me, there is no RCD rated at 50 amperes.

A protective voltage relay is not necessary, but I still recommend installing it - it will save your equipment in the event of a power surge, for example, a zero break (although this is not a common occurrence, nevertheless, such topics regularly arise on the forum). The cost of such relays as of 2016 is ~2500 rubles, which is disproportionately less than the cost of even the simplest TV, and repairs due to overvoltage are not guaranteed. Here is one example of such a relay:

Since the amount of text on the site is limited, read the continuation in the second part of the article. It will talk about designing and assembling a shield based on an example from the forum.

Second part of the article.

I hope the information was useful to you.
Regards, Alexey.

Option 1

This is the simplest circuit of an input panel with an electricity meter. It shows the TN-S grounding system, that is, when separate independent neutral working and neutral protective conductors come from the power source. In this single-phase switchboard circuit, there is a two-pole circuit breaker at the input.

Here and in subsequent diagrams, the ratings and characteristics of protective devices are chosen arbitrarily. Yours may differ, but the very essence of the connections between circuit breakers and other protective devices remains the same.

After the opening machine there is a counter. To register it, the input switching device and the electricity meter itself must be sealed. Next come single-pole group circuit breakers. The phase is always supplied to the circuit breakers, and the zero to the zero bus. It turns out that all neutral working conductors of different groups are combined with each other, and phase conductors are switched using automatic machines.

This version of the scheme is the simplest and is very often found at various sites.

The final stage

The shield is installed in its place after all dirty repair work is completed. The panel body is mounted in a niche, the DIN rails with the assembled modular equipment are fastened with self-tapping screws. The working (N) and protective (PE) zero buses are fixed. Phase and neutral wires are arranged in separate bundles and laid on opposite sides of the shield. The force with which the connections are clamped is 0.8 Nm.

Before starting commissioning work, you should make sure that all sockets, junction boxes, and switches are assembled. All consumer groups should be signed on the external panel of the electrical panel. After about a month of work, all connections of the shield should be tightened.

Option 2

This version of the shield is similar to the previous scheme. The only thing missing here is an electricity meter. These types of panels are used if the meters are located on the street in metering panels or on the landing in floor panels. The first option is relevant for the private sector, and the second for apartment buildings. Since almost all connections between protective devices are described in the first option, there is nothing special to comment on here.

The only thing that can be noted here is that at the input, instead of installing a circuit breaker, you can select a switch (load switch). It is necessary to manually turn off the entire shield. Installing a machine here will lead to duplication of the rating of the input circuit breaker from the metering panel or from the floor panel. There is no need to do this.

Shield marking according to GOST

How are the shields marked? According to GOST, each shield has a different design model and has its own marking. The marking has a structure that indicates:

1) Purpose – ShchE (floor board);
2) Number of apartments for which it is designed – 2, 3, 4;
3) Type of execution – B – built-in, N – mounted;
4) Number of compartments – 1, 2, 3.

For example, take a panel with the designations ShchE-4N-3, the abbreviation stands for: floor panel, designed for four compartments, hinged, three compartments. At the same time, there are four viewing windows on the front door for taking readings.

If there are no numbers after the letters ШЭ (only the letter В/Н), this indicates that the shield is supplied without inspection windows.

Another example of ShchEr-V-1. The letter “r” means that the shield is made in the form of a frame. The front part is as it should be, but at the back there are only brackets for mounting in a niche. It stands for: a floor panel in the form of a frame, internal design, without viewing windows, with one compartment.

What a floor plan for 4 apartments should not look like

In the photo you can see a floor board for four apartments in a nine-story building built back in 1980. Qualified electricians have not looked at this panel for a long time. Here, the residents of one of the apartments replaced the old bag machine with modern machines. Moreover, two independent machines are installed, each connected to phase and zero, respectively. It is not right. In this case, a two-pole circuit breaker must be installed, which, when disconnected, will break both poles simultaneously.

On top are old Soviet circuit breakers. The first thing that struck me was not that they should have been thrown away long ago, but how they were connected. A comb-shaped busbar made of bare aluminum wire. A couple of millimeters from this wire is the metal body of the shield.

Not only is it dangerous for an inexperienced person to open such a shield. I am already silent about people passing by who may accidentally touch the shield body.

In addition, these black machines need to be replaced a long time ago, since most of them are not capable of performing their functions. Sometimes you just turn off the machine manually, but you can’t turn it on again, because the trigger mechanism inside has simply crumbled.

I went down to the floor below in the same house. It seems that the machines were connected by the same electrician on all floors. This floor panel has a similar picture - the machines are connected with bare wire in the form of a loop. Some of the residents replaced the old automatic machine in their apartment and installed a new modern one.

But again, there was a mistake with the choice of denomination. The wire connected to the machine has a cross-section of 2.5 mm2, and the machine has a 25 Ampere rating. It is not right. A cable with a cross section of 2.5 mm2 can withstand a load of 27 A on average. A circuit breaker with an overload of 45% can operate and not turn off for 1 hour. Now we calculate: 1.45 * 25 A = 36 A. This is the current that the machine can hold for 1 hour and not turn off. Over such a time and under such loads, the wire (with a cross-section of 2.5 mm2) will simply melt.

I am sure that if the owners of the apartment: “why do you have a 25 Amp machine”? The answer will sound something like this: yes, because the electrician said not to knock it out. And then people wonder why apartments are burning...

In the photo below you can see how the neutral wire going to one of the apartments will soon burn out.

And here is another photo of the melted neutral wires going from the main to the meters. Moreover, it is clear that one of them has already burned out. To build it up, the popular “twisting without insulation” method was used.

This photo shows a branch of phase conductors and a neutral conductor, or rather PEN from the main line. The main line is made of four wires - three phases A, B, C and a PEN wire. The grounding system in this case is TN-C. There is no separate grounding; the neutral and grounding wires are combined.

The main line is made of aluminum wire with a cross-section of 16 mm2. The main trunk line is branched off without breaking on all floors of the house.

It may appear that the phase is connected to the metal part of the shield. However, it is not. If you look closely between the housing and the terminal, you can see a special insulating stand.

Power is supplied from the phase terminals to the package switches. All wiring is made with APV grade aluminum wire with a cross section of 2.5 mm2.

And here are the branches of the main PEN conductor. The wire fits tightly onto the panel body without breaking.

Floor board diagram for 4 apartments

Friends, let’s, based on the photos discussed above, try to figure out all the “snot” that is there and understand what the electrical diagram of a floor panel for 4 apartments .

Friends, I also wanted to point out that the diagram of the floor panel that is presented here in format is very voluminous; if you publish it in full format, the drawing will take up half the screen, so I will break it into several fragments.

Single-line diagram of a floor plan for four apartments.

The first thing we can say is that the power supply to each apartment is single-phase. If only because all the meters are single-phase. In the panel we see a minimum of equipment: a packet switch, an electric energy meter, automatic machines.

Each floor panel receives power from the main line, which runs along the entire riser, from the first floor to the last (see photo with a branch of 3 phases and a neutral wire). Each phase of the main line is connected without interruption to the terminal block. The combined PEN conductor is connected directly to the panel body.

Then two wires go from the terminal blocks to the package switches. The connection is made with aluminum wire with a cross section of 2.5 mm2.

If all this is voiced, then the diagram of the floor panel will be as follows:

For apartment No. 1, phase “A” and zero go from the terminal block to the package. For apartment No. 2, phase “B” and zero go from the terminal block to the package. For apartment No. 3, phase “C” and zero go from the terminal block to the package. For apartment No. 4, phase “A” and zero go from the terminal block to the package.

Next, the wires from the packager are connected to the meter and distribution occurs among apartments. A two-pole packet switch (batch switch) is installed in front of each meter. With its help you can turn off the power to the entire apartment. This is a kind of switch that can be used to turn off the voltage when replacing the meter. After connection, the meter is sealed and access to its contacts is closed.

Next, the phase wire leaves the meter and is connected to circuit breakers (each for its own apartment). The neutral wire comes out of the meter and is connected to the terminal block, and from it goes to the corresponding apartment.

The circuit in floor panels is carried out in such a way as to load all phases evenly. For example, one apartment is connected to phase “A”, the second to phase “B”, the third to phase “C”. It is clear that if the floor has 4 apartments, then two apartments will be connected to one phase at once.

On the next floor, the distribution of apartments proceeds in exactly the same way, but two apartments are already connected to a different phase.

Thus, a more or less uniform load is achieved across all three phases.

Power to each apartment must come from circuit breakers. Under no circumstances should you connect up to the meter to the packet terminals or directly to the main line branch terminals. This is already considered theft of electricity and is subject to a fine.

On the diagram of the floor panel you can see a smiling circle that looks like a smiley face - this is the designation of the panel socket. In the first photo you can see it in the upper right corner.

Similar materials on the site:

Option 3

As I wrote above, all groups of sockets must have protection against current leakage, that is, they must be protected using an RCD. The third version of the circuit presents an introductory RCD, which is installed after the meter. An RCD cannot be installed before the metering device, since it will need to be sealed, which inspectors do not want to do. That's why they only allow it to be placed after the counter.

To protect people, you need to use an RCD with leakage currents of 10-30mA. This is a safe current for a person, in which he is able to withdraw his hand and not receive any injury. The option using one 30mA RCD at the input has one drawback. When it is triggered, the entire apartment, house, etc. is switched off. Also, if the network is highly branched, then the RCD may trigger falsely due to natural leakage currents that are present in every household appliance.

Types and sizes of electrical panels

We will talk about cabinets/drawers and their varieties. Depending on the type of installation, electrical panels are available for outdoor and indoor installations. The box for outdoor installation is attached to the wall with dowels. If the walls are flammable, an insulating material that does not conduct current is placed underneath. When mounted, the external electrical panel protrudes above the wall surface by about 12-18 cm. This must be taken into account when choosing its installation location: for ease of maintenance, the panel is mounted so that all its parts are approximately at eye level. This is convenient when working, but can pose a risk of injury (sharp corners) if the location for the cabinet is poorly chosen. The best option is behind the door or closer to the corner: so that there is no possibility of hitting your head.

Electrical panel housing for outdoor installation

A panel for hidden installation requires the presence of a niche: it is installed and walled up. The door is flush with the wall surface; it may protrude a few millimeters, depending on the installation and design of the particular cabinet.

The cases are metal, powder-coated, and plastic. Doors are solid or with transparent plastic inserts. Various sizes - elongated, wide, square. In principle, you can find a suitable option for any niche or conditions.

One piece of advice: if possible, choose a larger cabinet: it’s easier to work in, this is especially important if you’re assembling an electrical panel with your own hands for the first time

Complete set and installation of a mounted distribution panel

When choosing a building, they often operate on such a concept as the number of seats. This refers to how many single-pole circuit breakers (12 mm thick) can be installed in a given housing. You have a diagram with all the devices listed on it. You count them taking into account the fact that bipolar ones have double width, add about 20% for the development of the network (suddenly you buy another device and there is nowhere to connect, or during installation you decide to make two from one group, etc.). And for such a number of “seating” places, look for a shield with a suitable geometry.

Option 4

In this version of the circuit, there is a 100-300 mA fire protection RCD at the input, and then some groups are protected by individual 10-30 mA RCDs. To prevent simultaneous operation of the input and group devices, it is recommended to install a selective RCD at the input. It has a time delay for operation and is designated on the case by the Latin letter “S”.

In this diagram, you must not get confused with connecting the neutral working conductors. Zeros after different RCDs cannot be combined with each other, otherwise the devices will immediately turn off. Therefore, after each RCD you need to install your own neutral bus if several groups are connected to it, or the neutral working conductor must be immediately connected to the RCD if it protects one group. This is exactly what is shown in the diagram below.

Option 5

In this option, difavtomats and conventional circuit breakers are used to protect groups. Automatic residual current switches (RCBOs) protect the cable from overload, from the action of short circuit current and protects a person from electric shock. Each difavtomat must be supplied with a phase and a zero. After logging out of these devices, you cannot combine zeros either. The neutral working conductors of the remaining groups, which are protected by conventional circuit breakers, are connected to the input common zero bus.

This article presents the simplest options for single-phase electrical panels. They discuss almost all protective devices, show how they need to be connected and contain descriptions of the use of one or another option. Based on your individual situation, you must develop your own scheme. Remember that it must meet all modern electrical safety standards.

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 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 construction Source ul-avesta.ru

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.

One machine is installed for each group of consumers, plus high-power equipment requires the installation of separate additional machines. Also in the shield there are buses - distribution, neutral, grounding.

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.

The electrical panel is the heart of the home electrical system.

We will not be mistaken if we say that the main function of an electrical panel installed at home, in an office, a cafe or any other room is to distribute electricity to consumers and ensure safety when using electrical appliances. Every owner of a residential or business premises at some point is forced to deal with the problem of how to assemble an electrical panel. Long-term uninterrupted operation of the huge number of household appliances that fill any home or office today largely depends on how correctly the electrical panel is assembled.

The shield itself is a plastic or metal box in which components (or modules) are placed, each of which performs a specific function. There are so-called internal electrical panels, that is, recessed into the wall, and external ones, located on the wall.

In a private home, the electrical panel is often installed outdoors; in this case, a waterproof design of the device will be required (protection level IP65). Considering the fact that it is unlikely that the electrical panel will be changed annually or even once every five years (as a rule, the device lasts much longer), it would be advisable when choosing a device to give preference to a more expensive, but high-quality panel of a well-known brand with a supply of seats.

We draw up a diagram of the distribution board

To assemble a single-phase panel with your own hands, you need a diagram. When compiling it, it is necessary to take into account the specifics of electricity consumption by the building:

power consumed by each individual group;
total design power;
number of consumer groups;
location of the electricity consumption meter.

The diagram should be drawn up in such a way that it is understandable and convenient. It is necessary to indicate the ratings of the devices, the cross-sectional area of the cable, and the wiring to consumers. An example can be found on the Internet.

The assembly diagram for a three-phase panel is in many ways similar to the diagram for a single-phase network voltage. The difference lies in the use of a different method of distributing consumers - each group is connected to its own phase. An important nuance is the need to maintain a load balance between all phases.

Selecting the shield body

As already described above, distribution boards come in surface-mounted and built-in types. If your wiring is hidden, then it is better to choose a structure recessed into the wall. The external shield can be mounted both inside the building and outside.

The issue of choosing the housing of such an electrical device is very important. First of all, you need to decide on its material. Plastic is not durable, but is lightweight, which makes installation easier. Metal stands out for its reliability and durability.

The optimal solution would be to purchase a case with removable walls - they facilitate the process of removing and moving DIN rails. As for the dimensions, it is advisable to have some reserve.

Everything is ready for installation

So, the diagram has been drawn up and understood, the components have been prepared - nothing prevents you from starting assembling the electrical panel. First of all, the location of the shield is selected, on which the device is attached, as a rule, with self-tapping screws or clamps. The electrical panel housing is usually located near the entrance to the house or apartment - in the vestibule or hallway. If the owner has expressed a desire to hide the panel in the wall, and the wall turns out to be concrete, you can use a false wall or a plasterboard ledge: the area of the room may be slightly reduced.

When choosing a place on the wall to install an electrical panel, you should take into account that the distance from the device to the nearest doorway should be at least 15 cm, the distance to the floor - 1.5–1.7 m. If necessary, the owner of the home or a called electrician should be able to easily reach the panel : It is strictly prohibited to place the device inside cabinets or other furniture. The device should be located away from gas pipes and flammable materials.

To prevent the electrical panel from being too large or small, you can first determine its size by knowing the dimensions of the components that will be located in it. For example, the width of a standard single-pole circuit breaker is 17.5 mm, a two-pole circuit breaker is 35 mm, and a three-pole circuit breaker is 52.5 mm. The remaining components have the following dimensions:

RCD single-phase two-module - 35 mm;
Three-phase four-module RCD - 70 mm;
single-phase two-module difavtomat - 70 mm;
terminal block on DIN rail - 17.5 mm (1 module);
counter (6–8 modules) – 105–140 mm;
voltage relay of 3 modules - 52.5 mm; This is not a mandatory element of the shield, but when used, you can protect equipment from power surges or sags, and save household appliances such as a refrigerator, TV, computer and other electronics from failure;
DIN rail socket (3 modules) - 52.5 mm.

The modules are located on the so-called DIN rail - a special metal plate 35 mm wide. The socket is not one of the required elements, but may be useful during repair work. If, when summing up the number of components, it turns out that a panel with 20 modules is needed, then it would be reasonable to install an electrical panel with 24 or even 32 modules - who can know how many household electrical appliances will be added to the house in a year, two or five?

Assembling the device

Let's look at the instructions for assembling the electrical panel. It includes the following steps:

Preparatory. Includes preparation of necessary tools and materials. You will need a set of screwdrivers, a multimeter, a knife and circuit elements.

Direct assembly of the shield. Includes installation of the housing, pulling cables, stripping wires, fastening DIN rails, circuit breakers and other devices, mounting busbars, as well as connecting all elements to each other.

What it is like to connect circuit breakers with wires can be found in the photo. We have already talked about how to assemble a switchboard with your own hands!

Modern shields have a modular design. A modern electrical panel has a durable casing and is locked, so children will not get in unless you leave the key in a visible place.

The electrical circuit is created in several stages.

The rating is selected depending on the power of the consumer.

Assembly and connection diagram To create an electrical panel diagram, you need to determine the type of power supply system in the house, divide electricity consumers into several groups, and based on this data, create a diagram using GOST. Thus, you can protect yourself from additional expenses in case of installing additional machines. If you turn everything on at the same time, then, of course, the input circuit breaker will trip and turn off the entire apartment. T 12.2 Assembly diagrams for a group apartment panel

Nuances of commissioning work

After the panel device is installed, it is necessary to turn off all devices with which it is equipped. Next steps:

load all sockets;
Apply voltage, check its presence at the input, correct phase and zero;
check the RCD and automatic circuit breakers one by one;
estimate the voltage at the input and output of the machines;
check the behavior of the shield when connecting high power equipment;
check sockets and switches.

Procedure

By strictly following the following instructions, you can open the shield without harm to your health:

First, figure out what series of devices is installed in your entrance. How many doors does it contain? A standard electrical panel has 3 of them:

the long door on the right - there are low voltage connections for the telephone and the Internet;
rectangular at the top left - automatic switches are located behind it;
the square one at the bottom left, equipped with special windows, contains electric meters for each of the apartments on the site.

Determine the types of locks on each of the doors. If they are made in the form of plates protruding forward, opening them will not be difficult. Regular pliers are suitable for this. By the position of the plate and tongue, you can determine whether the lock is locked or not. Sometimes, the locks on electrical panels are the same as those on mailboxes. In this case, each resident receives his own key and can easily use it.
After you have managed to open the first door, follow the safety rules and do not harm the property of the management company, namely:

do not touch the wires and metal parts in the panel, they may be under high voltage;
do not repair the system yourself, even if you have basic electrical skills;
do not try to stop or turn off the meter, or exert any external influence on it, it is owned by the management company and you may be held accountable by law for its breakdown;
do not cut off the power supply to other apartments, except in cases of emergency, for example, if one of the residents is electrocuted.

If your panel is equipped with electronic meters, using special buttons you can get information about the electricity used (per month, day or night). At the same time, it’s worth overcoming your curiosity and not meddling with your neighbors’ appliances. Press the buttons with the greatest care so as not to touch the current conductors. How to properly use electronic meters should be described in detail in the instructions located next to the switchboard. Using the system, you can only familiarize yourself with the incoming data, but you cannot change the readings or stop the meter.
To fix electrical problems, follow these steps without waiting for a professional to come:

open the door, the one with the machines (yours should be marked with the appropriate numbers, they match the apartment number);
before turning off the power, be sure to unplug computer equipment and other devices from the sockets, the operation of which may be affected by a sudden blackout;
determine which machine is responsible for the sockets;
In emergency situations, machines must be turned off immediately, regardless of the type of operating devices.

Before carrying out repair work on wiring, it is necessary to take care of the safety of the craftsmen. To do this, there must be a person on duty next to the switchboard who will not allow the power to turn on.
After completing all work with the devices in the panel, restore the power supply and securely close all doors with a lock.