Control electrical energy possible using special switches with one or more active poles. Depending on the needs, a two-pole or single-pole circuit breaker is often used for this.

Principle of operation

Single-pole switches (IEK) GOST R 50345-99 are an important part of the electrical distribution system, as they help to safely control branches from the distribution panel. They are primarily used to supply 120 volts of power, while the two-pole ones supply 240 volts to the circuit. Single-pole circuit breakers are available in a wide range; in the store you can buy 16, 20 and 30 Amp circuit breakers. The most common single-pole circuit breakers are 16A and 25A.

Photo - ABB single-pole circuit breaker

The circuit of a single-pole switch, like a two-pole switch, is designed to protect electrical networks and devices connected to them. A differential device (difavtomat) turns off the load when it exceeds permissible norm. In this case, a power outage can also occur at the moment short circuit system, or if the parallel network is overloaded.

Photo - instrument housing with single-pole circuit breakers

This is a necessary device in the country or at home. Advantages single-pole RCD with independent connection:

1. Protection of electrical devices from power surges. The device also controls the number of devices connected to local network, and if an overload occurs, it stops the current supply. If this were not done, there would be a possibility of a wiring fire;
2. Protection of wiring in the apartment from overload;
3. Affordability - the device is cheaper than a two-pole electric machine.

Some contactors are also equipped with a thermal response mechanism. They are called single-pole thermomagnetic circuit breakers. Such systems can be installed in networks that, when overloaded, heat up and can catch fire.

Specifications

Naturally, each model has certain power and throughput parameters. We suggest you consider specifications automatic single-pole circuit breaker type ABB (ABB):

1. Initial network voltage – 230–400 V;
2. Rated (initial) current – ​​16A;
3. Frequency – 50Hz;
4. Capacity (up to a switch with a power of 60 A) – at least 4.5 kA;
5. Operability up to 10 thousand shutdowns and starts;
6. Guaranteed circuit strength - up to 10 thousand shutdowns and starts;
7. There is one pole (hence the name “single-pole”), in contrast to a two-pole machine, which, accordingly, has two of them;
8. Class fire safety and protection against penetration of vapor and solid particles under the body - 20IP;
9. The maximum connection wire size is 25 mm 2 ;
10. Shutdown speed - less than 0.1 seconds;
11. The current determines the certificate of a specific device.

From this series, the BM40 automatic modular switch is most often used. It is known for its ability to pass up to 32 Amps, while providing a maximum number of operating cycles (off-on) - up to 30. The same way The Legrand, Schneider electric Multi9 (25 A), Merlin Gerin and ABB SH201-B6 automatic machines also have actions.

Photo - marking of single-pole circuit breakers

In addition, a single-pole circuit breaker is also divided into kinds:

1. A – this type is used to connect a group load in residential buildings or apartments, used in domestic conditions;
2. B – used to protect networks that are connected to heavy loads. Most often these are personal lighting or homes with increased energy consumption needs. Used in systems with a ratio of 3÷5 In;
3. C – required for connection industrial buildings, factories, companies and other industrial networks.

Video: Connecting a single-pole circuit breaker

Installation of a single-pole circuit breaker

Let's look at how to connect a single-pole circuit breaker to a DIN rail:

Quite often, home electricians use circuit breakers with a special release. A device with such a mount can be removed from the DIN rail and other surfaces very quickly, since it can be removed by simply pressing the installation “crocodile”.

Photo - the principle of connecting RCD machines

If you cannot connect the contactor yourself, we recommend that you seek help from specialists. Installing a single-pole circuit breaker will cost approximately 150–200 rubles (the price may depend on the specific electrical company).

Photo - installation principle circuit breakers

Remember, before installing or changing any circuit breaker (with one or more poles), you must obtain permission from your energy supply company. Otherwise you may be fined. It is also recommended that you first agree on the parameters and technical characteristics of the selected contactor with a professional electrician.

Price overview

In order to buy a single-pole circuit breaker, you need not only to calculate the installation parameters you need (load, throughput, shutdown speed), but also dimensions. Approximate prices for different types machines:

Models produced in Russia and the CIS countries are not inferior in quality and performance, but are much cheaper. You can order directly from the factory or by visiting official dealers.

You can buy machines at any electrical tools store in St. Petersburg, Moscow and other cities. Before choosing the right model, be sure to check its passport and quality certificate to protect yourself from counterfeits.

Before proceeding with the installation of circuit breakers, it is necessary to determine the operating conditions electrical network with its characteristics:

• By current;
• By voltage;
• Electrical power of devices that will be connected as a load.

The type and characteristics of the selected circuit breaker, and, accordingly, the methods of its installation and connection depend on this.

Purpose and scope of circuit breakers

Circuit breakers are control elements of the switching system and perform three main functions:

• Conventional switch, on and off;
• Disconnecting the load from the network when the set current threshold is sharply exceeded, this happens when there is a short circuit in the circuit or a malfunction of the load equipment;
• Some circuit breakers trip when the current suddenly drops when appliances that consume large amounts of electricity are turned on. To eliminate malfunctions on expensive equipment during large surges in voltage and current in the network, the machines switch off the load.

All these machines have different technical characteristics and design features.

Main types of circuit breakers

Manufacturers make many varieties various models, despite their design differences.

Appearance various types circuit breakers
They all work on the same principle and are designed for the same purpose. If exceeded established threshold magnitude of the current, they disconnect the circuit from the power source to preserve the equipment from overloads.

Based on their purpose, circuit breakers can be divided into the following types::

• For switching equipment in lighting, socket networks, power lines with household equipment not much power;
• For switching power supply to electrical installations that are operated in extreme conditions, in explosive environments, high humidity or dustiness;
• For repeated switching of semiconductor devices in various electronic systems.

By design features divided into three main types:

• Air switches have holes in the housing design through which the elements inside are ventilated. Such models are used in normal dry operating conditions, without fumes and dust;
• Switches with molded housings are used in extreme operating conditions;

• Modular switches are one of the air switches; the design feature is that their dimensions and fastening mechanism are standardized.

The latter option is in greatest demand among consumers at the domestic and industrial level. The reason for this popularity is the versatility of these models, ease of installation and connection. Therefore, we will look in detail at how these circuit breakers are connected.

Characteristics and selection criteria for modular circuit breaker

When choosing a modular circuit breaker, the following characteristics must first be taken into account:

• Maximum breaking capacity measured in kA (kiloAmperes) - this is the current value at which the machine still remains operational. The minimum value of this parameter on industrial and household networks is from 3 kA to 10 kA;
• Time - current characteristic, sometimes this value is called the sensitivity of the circuit breaker to current overloads.

In terms of sensitivity, the switches have three classes, B - the circuit breaker is switched off when the rated current is 3-5 times higher than the rated current for a certain section of the network. C – 5-10 times and D 10 – 20 times, when operating equipment with electric motors, group B option is not recommended, short-term starting currents may cause unreasonable, frequent shutdowns. The universal option is considered to be C, for electric motors D.

• Rated current section of the network, when a shutdown occurs, switches are manufactured with values ​​​​in the range of 0.5 - 125 A for modular designs. For industrial input circuit breakers, this value can reach thousands of Amperes.
• Number of poles on the switch there can be from 1 to 4, The width of the housing of a single module depending on the product series, 18mm, compact version half smaller than 9mm, extended 27mm.

Taking these parameters into account, a selection of switches is made for a specific section of the network, after which a diagram of their connection is drawn up or studied.

Circuit breaker connection diagrams

The classic option is to enable automatic modular switches into the network diagram is carried out when placing them in switchboard. Fastening is carried out on a factory din-rail located horizontally inside the shield. Wires leading to the load are inserted into the space between the rail and the rear wall of the cabinet. They are connected to the lower output contacts of the machines; the input, upper contacts are connected to the wire from the output of the input machine.

On back wall The machine has a channel made under the rack, the upper edge of the body clings to the rack and by pressing on the front plane of the body, a lever with a spring fixes the lower part of the body to the rack. The machine is removed from the rack in the reverse order, the lever is pulled back and retracted Bottom part housing, lifting it up, thus the entire housing is removed from the rail.

Tip No. 1 High-power input circuit breakers that are not equipped with DIN-rail mounting are separately mounted on a metal plate installed in the panel with holes and threads for bolts. Holes in the machine body for fastening to the shield body are provided by the design; metal screws can be used.

Single-pole circuit breakers

Connecting single-pole circuit breakers is considered the simplest; they are connected to socket and lighting groups.

Two-pole machines

More powerful appliances, such as electric stoves, heating boilers, shower cabins, split systems and others, where it is necessary to ensure a complete circuit break, zero and phase wires connected through two-pole devices.

Three-pole machines used in three-phase networks using powerful devices with appropriate power supply of 380V. These can be heating elements, electric motors and others. When, when the rated current is exceeded, all three phases are disconnected, thus eliminating phase imbalance in the entire circuit when the current is exceeded in one of the three lines.

Four-pole machines are connected to a three-phase network as input circuit breakers, where the phases are used as separate network lines with individual load elements. In this case, it is necessary to try to distribute the magnitude of the load currents evenly among the phases to avoid phase imbalance. To remove excess currents, a neutral wire is used, a circuit with a grounded neutral.

Connecting a circuit breaker in an electrical panel is not a difficult process. And the procedure won’t take you much time. However, this does not mean that installing automatic machines is not fraught with pitfalls. After all, mistakes made can cause the device to break down in the future. How to do everything right if you are new to electrics and are not completely confident in your capabilities?

Let's figure out together how to connect a circuit breaker yourself and how to avoid primitive mistakes.

Standard installation errors

Most often, a novice electrician, out of ignorance, makes one of the following mistakes:

1. The power cord is connected from below. Yes, according to the rules of the PUE, this option is quite acceptable. However, we do not recommend doing this. It is better to connect the power from the top (as you will once again be reminded of by the special diagram printed on the front panel of the device case).
2. The contacts are excessively clamped by the fixing screw. Don’t be afraid to “not press too hard”, because otherwise you risk damaging both the cable itself and the body of the product.
3. Conductors are connected incorrectly. To avoid this, you need to remember a simple rule: the phase is connected strictly to the phase, the zero - strictly to zero (of course, this is only relevant for a two-pole switch).
4. Two single-pole circuit breakers are used instead of one double-pole circuit breaker. This technique is strictly prohibited, because the zero and the phase must be disconnected simultaneously.
5. Insulation material getting into seat during the process of fixing the core. The wire must be stripped thoroughly and to the extent required by the model data sheet. Did you press down the insulating layer with a fixing screw? Get a weak conductor contact. As a result, further heating of the core with all the ensuing unpleasant consequences. To remove insulation, we strongly recommend using special tool– for example, the same stripper.
6. Incorrect choice of circuit breaker, due to which the product simply cannot withstand the level of incoming load. In such a situation, you first need to perform, based on which you should select the device model.
7. Rounding up the value obtained during calculation. Let’s say that during the calculation process you received the value of the current load on the product, which is equal to 19 Amperes. An inexperienced person will immediately go to the store with a clear goal - to buy a 20 Ampere device (so to speak, with an additional reserve). Please note this serious mistake! The value obtained during the calculation is nominal, and the protection must operate at a current load that does NOT reach the calculated value. If the calculated value is 19 Amps, go to the store for a switch with a reading of 16 Amps. This way you will protect the wiring in your home and it will last much longer.

I would also like to touch on another important point: how to connect the machine - before the meter or after it?

We answer: if it is more convenient, then you can safely connect the device in front of the electric meter. In fact, it's even better. You will only need to buy a special box, the sealing of which is carried out by a representative of the energy sales company. With such a connection, it can be easily replaced both in an apartment and in a private house.

Instructions for connecting a circuit breaker

What do we have? We have an electrical panel, wires (input and output) and connected devices. Let us describe the algorithm of actions using the example of installing a two-pole circuit breaker. Go:

1. First, turn off the electricity and, to be sure and safe, check its absence using either a multimeter or a multimeter.
2. We install the machine on the landing rail and snap the latch.
3. Carefully, but thoroughly, strip the conductor cores (both incoming and outgoing) by approximately ten centimeters.
4. We connect the phase and input zero to the two upper terminals, focusing on the recommendations given above.
5. Next, we fix the outgoing phase and zero in the two lower holes (those phase with zero that go to electrical consumers - sockets, switches, household appliances and so on).
6. Did you do everything right? Great, let’s check the results of our work for reliability. We take the conductors in our hands and try to gently move them in one direction or the other. If the connections are reliable enough, the cores will remain in their original places. If you feel that there is something unsatisfactory about the strength of the conductor fixation, tighten the fixing screws a little and you’re done! We also recommend that you familiarize yourself with.
7. Now the task is completed. All that remains is to “start” the current through the system again by turning on the power supply. Voltage is supplied to the network, the performance of our product is checked.

As you can see, the mechanism of operation is not at all complicated. Using the described algorithm, you will confidently connect a circuit breaker in a single-phase circuit.

Connection diagrams

That’s right, the machine’s connection diagrams are unlikely to be superfluous. Here are four options:

It’s hard to imagine a switchboard without modern modular devices protection, such as circuit breakers, residual current devices, differential circuit breakers and all kinds of protection relays. But these modular devices are not always connected correctly and reliably.

In view of servicing electrical panels, I sometimes have to deal with errors in connecting the circuit breakers that are installed in them. It would seem, how can you connect an ordinary single-pole circuit breaker incorrectly? I stripped the cable to a certain length, inserted it into the terminals, and tightened the screws securely.

But no matter how strange it may sound, most people have “clumsy” hands and the build quality of the shields leaves much to be desired. Although in fact we all make or have made mistakes in one industry or another, and as the famous proverb says: “he who does nothing makes no mistakes.”

I welcome all friends to the “Electrician in the House” website. In this article we will look at and analyze several options for the most common and serious mistakes.

Connecting machines in the panel - entrance from above or below?

The first thing I would like to start with is the correct connection of the machine in principle. As you know, a circuit breaker has two contacts for connection, movable and fixed. Which pin should be connected to the top or bottom? To date, there has been a lot of controversy regarding this matter. There are a lot of questions and opinions on this matter on any electrical forum.

Let's turn to regulatory documents for advice. What does the PUE say about this? In the 7th edition of the PUE, clause 3.1.6. said:

As you can see, the rules say that supply wire when connecting machines in the shield should be connected, as a rule, to fixed contacts. This also applies to all ouzo, difavtomat and other protection devices. From this entire clipping, the expression “as a rule” is not clear. That is, it seems to be as it should be, but in some cases there may be an exception.

To understand where the moving and fixed contacts are located, you need to imagine the internal structure of the circuit breaker. Let's use the example of a single-pole circuit breaker to look at where the fixed contact is located.

Before us is an automatic machine of the BA47-29 series from iek. From the photo it is clear that its fixed contact is the upper terminal, and the moving contact is the lower terminal. If you look at the electrical symbols on the switch itself, you can also see here that the fixed contact is on top.

Circuit breakers from other manufacturers have similar markings on the housing. Take, for example, a machine from Schneider Electric Easy9; its fixed contact is also located on top. For Schneider Electric RCDs, everything is similar on top there are fixed contacts and moving ones below.

Another example is safety devices from Hager. On the housing of the hager circuit breakers and RCDs you can also see symbols, from which it is clear that fixed contacts are on top.

Let's figure out whether it makes sense from the technical side, how to connect the machine from above or below.

The circuit breaker protects the line from overloads and short circuits. When overcurrents occur, the thermal and electromagnetic releases located inside the housing react. From which side the power will be connected from above or below to trigger the releases there is absolutely no difference. That is, we can say with confidence that the operation of the machine is not affected by which contact the power is supplied to.

In truth, I should note that manufacturers of modern “branded” modular devices, such as ABB, Hager and others, allow power to be connected to the bottom terminals. For this purpose, the machines have special clamps designed for comb tires.

Why do the PUE recommend connecting to fixed contacts (top)? This rule was approved for general purposes. Any educated electrician knows that when performing work it is necessary to remove voltage from the equipment on which he will work. When “climbing” into the shield, a person intuitively assumes the presence of a phase at the top on automatic machines. Having turned off the AV in the panel, he knows that there is no voltage at the lower terminals and everything that comes from them.

Now let’s imagine that Uncle Vasya, an electrician, did the work for you and connected the phase to the lower AB contacts. Some time has passed (a week, a month, a year) and you have a need to replace one of the machines (or add a new one). Electrician Uncle Petya comes, turns off the necessary machines and confidently reaches into the voltage with his bare hands.

In the recent Soviet past, all machine guns had a fixed contact at the top (for example, AP-50). Nowadays, based on the design of modular AVs, you can’t tell where the movable and where the fixed contact is. For the ABs that we discussed above, the fixed contact was located on top. Where are the guarantees that Chinese machines will have a fixed contact located on top?

For those who do not agree with me, the question is why on electrical diagrams The power supply to the machines is connected precisely to the fixed contacts.

If we take, for example, a regular switch of the RB type, which is installed at every industrial facility, then it will never be connected upside down. Connecting power to switching devices this kind applies only to the upper contacts. I turned off the switch and you know that the lower contacts are without voltage.

We connect the wires to the machine - a cable with a monolithic core

How do most users connect machines in the control panel? What mistakes can be made in this case? Let's look at the most common errors here.

Error – 1. Insulation coming into contact.

Everyone knows that before you need to remove the insulation from the connected wires. It would seem that there is nothing complicated here, I stripped the core to the required length, then we insert it into the clamping terminal of the machine and tighten it with a screw, thereby ensuring reliable contact.

But there are cases when people are perplexed why the machine burns out when everything is connected correctly. Or why the power in the apartment periodically disappears when the wiring and filling in the panel are completely new.

One of the reasons for the above contact with wire insulation under the contact terminal of the circuit breaker. Such a danger in the form of poor contact carries the threat of melting of the insulation, not only of the wire, but also of the machine itself, which can lead to a fire.

To eliminate this, you need to monitor and check how the wire is tightened in the socket. Correct connection circuit breakers in the distribution board should exclude such errors.

Error - 2. You cannot connect several wires of different sections to one AB terminal.

If the need arises connect several machines standing in the same row from one source (wire) for this purpose is impossible would be better suited comb tire. But such tires are not always at hand. How to combine several group machines in this case? Any electrician, answering this question, will tell you to make homemade jumpers from cable cores.

To make such a jumper, use pieces of wire of the same cross-section, or better yet, do not break it along its entire length. How to do it? Without removing the insulation from the wire, form a jumper the desired shape and sizes (according to the number of branches). Then we strip the insulation from the wire at the bend to the required length, and we get an unbreakable jumper from a single piece of wire.

An example of connecting circuit breakers with jumpers from different cable sections. The first machine receives a “phase” with a 4 mm2 wire, and the other machines already have jumpers with a 2.5 mm2 wire. The photo shows that jumper made of wires of different sections. As a result, poor contact, increased temperature, melting of insulation not only on the wires, but also on the machine itself.

For example, let's try to tighten two wires with a cross section of 2.5 mm2 and 1.5 mm2 into the terminal of the circuit breaker. No matter how hard I tried to ensure reliable contact in this case, nothing worked. A wire with a cross section of 1.5 mm2 was hanging loosely.

Another example in the photo is a difavtomat, into the terminal of which they plugged two wires of different sections and tried to tighten the whole thing securely. As a result, the wire with a smaller cross-section dangles and sparks.

Error – 3. Formation of the ends of wires and cables.

This point most likely refers not to an error, but to a recommendation. To connect the cores of outgoing wires and cables to the machines, we remove the insulation from them by about 1 cm, insert the bare part into the contact and tighten it with a screw. According to statistics, 80% of electricians make connections this way.

The contact at the junction is reliable, but it can be further improved without extra costs time and money. When connecting to machines cables with monolithic core make a U-shaped bend at the ends.

This formation of the ends will increase the area of ​​contact of the wire with the surface of the clamp, which means the contact will be better. P.S. The inner walls of the AB contact pads have special notches. When the screw is tightened, these notches cut into the core, thereby increasing the reliability of the contact.

Connecting stranded wires to the machine

For wiring panels, electricians often prefer flexible wire with stranded conductor type PV-3 or PuGV. It is easier and easier to work with than with a monolithic core. But there is one peculiarity here.

The main mistake that beginners make in this regard is connecting stranded wire to the circuit breaker without termination. If you crimp a bare stranded wire as it is, then when tightening, the strands are crushed and break off, and this leads to a loss of cross-section and deterioration of contact.

Experienced “specialists” know that it is impossible to tighten a bare stranded wire into a terminal. And for terminating stranded conductors, you need to use special tips NShV or NShVI.

In addition, if there is a need to connect two stranded wires to one terminal of the machine for this you need to use a double tip NSHVI-2. Using NSHVI-2 it is very convenient to form jumpers for connecting several group circuit breakers.

Soldering wires to the terminal of the machine - ERROR (error)

Separately, I would like to dwell on this method of terminating wires in a shield, such as soldering. Human nature is such that people try to save money on everything and do not always want to spend money on all kinds of tips, tools and all sorts of modern small things for installation.

For example, consider the case when an electrician from the housing office, Uncle Petya, performs wiring electrical panel multi-core wire (or connects outgoing lines to the apartment). He does not have NShVI tips. But you always have a good old soldering iron at hand. And the electrician, Uncle Petya, finds no other way out than to tin the multi-wire core, pushes the whole thing into the contact clamp of the machine and tightens it with a screw. Why is this dangerous?

When assembling distribution boards, DO NOT solder or tin the stranded core. The fact is that a tinned connection begins to “float” over time. And for such contact to be reliable, it must be constantly checked and tightened. But as practice shows, this is always forgotten. The soldering begins to overheat, the solder melts, the joint weakens even more and the contact begins to “burn out.” In general, such a connection can lead to a FIRE.

Therefore, if a stranded wire is used during installation, then NShVI lugs must be used to terminate it.

Installing an electrical panel with your own hands with minimal knowledge about wiring and electricity is quite easy. real challenge. You just need to carefully and thoroughly study the instructions for connecting the machines in the switchgear and do everything strictly in accordance with it.

The worst thing that can happen if the wires are wired incorrectly is a short circuit, which can lead to the most undesirable consequences. In theory, a common circuit breaker, which should be in the circuit earlier than the mounted panel, should eliminate these consequences.

If we are talking about a floor panel in a city residential building or an individual one located in an apartment, then a circuit breaker will be a faithful protector. It could be three phase switch or single-phase - it all depends on the wiring diagram in the house.

Everything becomes more complicated when working with the wiring of a private house. In this situation, you must be protected by a machine located in the transformer booth from which the line is extended to you. Sometimes there are intermediate transformers that can be seen on power line supports in rural areas. They are often supplemented with protective fuses that prevent the transformer from failing when accidents occur on the line.

But if you know exactly the rules for connecting the machine in the control panel, you can avoid emergency situations. In this case, you have the only unpleasant and somewhat dangerous job - connecting the assembled device “hot”, that is, to live wires. Or you will need to call an electrician who will remove the voltage from the line during installation.

But first, let's look at the installation and connection stages.

Grounding device

In many ways, the electrical circuit of the floor panel depends on the house itself. As a rule, in a private house, if there are no plans to connect such powerful devices as three-phase boilers, then a single-phase line is started. These are two wires: zero and phase. In internal wiring, it is customary to wire the phase wire with a conductor in brown insulation, and the neutral wire with blue insulation.

If the wire is three-core, then the third core is usually painted yellow with a green stripe. This bright conductor is used for grounding. It is never put into the machine inside the shield. The grounding conductor must be continuous, therefore, in switchgears, special conductive blocks are used, which are installed next to the machines in order to pass the grounding conductor through them and safely bring it to the floor where it is connected to the grounding bus. As a rule, this is either the first floor, or the basement, or the basement.

How to connect the phase and neutral wires

Connecting the phase conductor to the machine is mandatory. The neutral conductor does not always have to pass through the machine, but there are cases when it is recommended to use a two-pole automatic switch, and then both phase and neutral pass through it - each wire through its own section.

Simultaneous disconnection of phase and zero is justified especially in those situations when a house or non-residential building is introduced three-phase voltage. In such situations, there is a greater risk that one of the phases may short circuit to zero. This is a short circuit mode to which the machine protecting this phase must respond. But in those fractions of a second while it is triggered, an overvoltage will occur in the other two phases. That is, instead of the required 220 V, there may be all 380 V - the voltage difference between the two phases with a conventional three-phase connection.

No one household appliance It is not designed for such voltage, and the more powerful it is, the more current it passes, and the greater the likelihood of it burning out due to overvoltage. Where the fuse of a low-power device immediately blows, powerful equipment will still “tolerate” a heavy load for some time, and during this time the switching power supply or transformer may fail. Therefore, equipment such as boilers, dishwashers and washing machines It is preferable to protect with two-pole circuit breakers that cut two circuits at once.

Keep in mind that phase imbalance is also harmful to the source that powers the building. A generator, a transformer box, a substation - all this will deteriorate very soon. For such purposes, there are special three-phase circuit breakers, which, in the event of a large imbalance or failure in one of the phases, can turn off all three phases at once. For more critical circuits, it is recommended to connect a four-phase circuit breaker, which also de-energizes the neutral wire.

Installation of a panel with automatic machines

So, let's look at several options.

IN modern houses they are trying to install a two-phase machine or at least a separate single-phase one on the “power equipment”. The equipment, in turn, can be divided into the following categories:

• washing machines;
• dishwashers;
• electric stoves;
• other powerful household appliances.

To do this, the device is connected separate wire, which usually contains neutral, phase and ground. That is, for each apartment there are three machines and one grounding conductor. Single-pole circuit breakers are used for sockets and lighting, so the zero will have to be connected to special blocks.

For example, we can consider a single-pole connection option. What does it mean? That is, only a phase will pass through the circuit breaker. Such a machine has one contact for phase input, the other for output. As you know, the input contact is located at the top, while the output contact is at the bottom.

Before connecting, you need to make sure by the marking near the top contact that it is really intended for the power conductor. To connect this wire, it must have brown or black insulation; it must be stripped of this insulation by 7–10 mm. The wire is inserted into the hole in the upper end of the machine and clamped with a screw located on the front of the case.

The outgoing wire is attached in the same way from the bottom end. This is exactly the wire that goes into the apartment. Here, too, it is important to monitor the markings of the conductors so that it does not turn out that the switch at the chandelier will interrupt zero and not phase. That is, the conductor coming out of the machine should not be zero for the apartment. While the apartment is de-energized, you can open the nearest switch and ring the wire from it with a tester before entering the apartment. If the tester shows conductivity, then this wire inside your apartment is wired as a phase wire.

However, connecting the machine in the panel may be fraught with another pitfall: if there is not one phase, but at least two, separated on the floor, then you must not confuse them, so that in the apartment there is no difference of 380 V between the sockets and chandeliers! No matter how many machines there are in an apartment, everything must be connected to the same phase.

Wiring

Experienced electricians use a little trick when they need to connect several machines and not make a mistake with the introductory phase. To do this, you need to take one conductor and strip not only its end, but also make intermediate stripped places in such a way that each of them can reach the contact of the machine.

Ideally, if the machines are located next to each other on a DIN rail, then these distances can be measured simply by attaching a conductor so that the transition part from one machine to another forms a loop. This will allow the wire to exit the housing vertically.

The stripped area should be twice as long as the end of the wire, because we will have to make a small loop out of it, which will be used to connect the machine. You will need to put heat-shrink tubing on this loop or tightly wrap it with electrical tape at the place where the insulation ends. This will give our wire rigidity.

Then the loop must be inserted into the contact hole of the machine and tightened tightly. The cleaned areas should correspond to the number of circuit breakers. But we will be sure that the phase is separated correctly - the same for the apartment.

A little about mechanics

Having dealt with the question of how to properly connect the machine, the question of how to install it remained unexamined. If you are planning a new shield, then most likely the first thing you will have to do is install a DIN rail there.

At each circuit breaker modern design There is a special clamp for mounting on this very rail. The feed-through contact, which is used for the grounding conductor, has the same fastening. By the way, the latch of such a grounding conductor is not made as a separate plastic element, but as a springy part of the body. This is very convenient, as there is no risk of losing a small but very important detail.

If it is not possible to find a pass-through element, the grounding connection can also be made by twisting. However, to be sure, you can tin the wires with a soldering iron and put heat-shrink tubing on them as insulation. This is completely justified. Do not forget that phase and neutral conductors still “walk” along the shields. If you don't have heat shrink tubing, you can use insulating tape. This will be no less protection against any surprises.

By the way, it is strictly worth remembering that the connection and even grounding cannot be done in such a way as to twist copper and aluminum wires. These two metals form a galvanic couple, which leads to their oxidation and disruption of conductivity between them. If it turns out that it is not possible to connect them through a pass-through element or a block with steel contacts, then you can tin each of the wires and carefully solder the connection.

Hot work

There are often cases and situations where work on connecting machines is performed in force majeure situations. An excellent example of such a current situation is the burnout or failure of the machine. Often it is necessary to connect a new circuit breaker when the panel is energized. What do you need to know for such work?

1. The first rule is not to panic and take your time.
2. The second rule is to use a special indicator screwdriver.

Let's look at everything in detail. If it is not possible to turn off the access panel, then from the “affected” machine, then you need to perform the following steps:

1. Remove the power, that is, unhook the input wire from it.
2. Wear sunglasses to protect your eyes from sparks and electrical protective rubber gloves.
3. Arm yourself with an indicator screwdriver and a regular screwdriver with an insulating handle.
4. On short-sleeved clothing, wear something with long sleeves over it.
5. Now carefully, without touching anything metal objects in the shield, since in the event of an accident a phase may “sit” on them, unscrew the input contact screw with one hand, and with the other hand remove and bend the wire so that it does not touch any metal surface.

It is prohibited to take this wire by its exposed part!

Sparking during such a shutdown is normal. The wire just needs to be pulled away from the contact confidently and quickly to a distance that cannot be penetrated by a spark.

Before connecting anything, you need to take an indicator screwdriver and examine the parts of the switchboard related to the apartment for the presence of voltage. If it is not there, then you can install and connect a new machine.

If in Switchgear Several phases occur, of course, they can also be turned off. However, this will result in you leaving your neighbors without electricity. Therefore, connecting a new circuit breaker will have to be done with an eye to the fact that there is one or two more phases in the panel.

Shorting the supply conductor, which you so skillfully disconnected from the damaged machine, with any other phase or with zero will lead to overvoltage and a real fireworks of sparks, from which clothing and glasses should be protected, just in case.

Why do you need a partner?

As you know, when working with electricity you need to take as many safety precautions as possible. Another practical advice specialists - this is repairing electrical wires with a partner.

The person chosen for this role may well not understand anything about electrical circuits. However, he must clearly know what to do if someone comes under voltage: pull the person by the clothes, without touching his body, away from the live wire.

It is advisable to first unbutton the jacket that you are wearing to protect your hands before making connections in the electrical panel. This is vital. The fact is that a free part is formed on the back, by which a person can be pulled away in the event of an electric shock. It will be convenient for your partner to grab onto it. Your partner should also remember how to call ambulance or to the rescue service.

The help of a partner can be invaluable when the shield is located high. He will be able to give or receive instruments. This way, you won’t have to constantly go down and get up again from a stool or stepladder.

Safety first

Summarizing all of the above, it must be said that you should never forget about safety when working with electricity. Neglecting at least one of them can lead to serious problems with health, and sometimes even to death.

A person who is poorly insulated from the ground can get an electric shock when touching a phase. Electricity will pass through the entire body and go into the ground. There are quite frequent cases when a person dies from exposure to current passing through the heart.

The grounding conductor is safe and can be safely handled. But even here you need to do this with caution and check it in advance for breaks in the wiring and electrical panel.

That is why it is vitally important to purchase special clothing, rubberized tools and use insulating materials for working with electrical wires.

Video: how to select and assemble a distribution board