Correct cable connection to the circuit breaker. Connecting a circuit breaker - how to do it yourself

Sometimes even the simplest manipulations and connection of simple electrical devices such as a light switch or a machine can cause a lot of questions. In principle, nothing is difficult, you just need to clearly understand:

1. the purpose of each element of the circuit;
2. safe methods of connecting the switch;
3. nominal values ​​of each apparatus;
4. know the power supply system and the geography of the location of electrical devices.

The list of tools that will be needed for this is also minimal:

1. An indicator screwdriver or a voltage indicator with a phase indicator;
2. A screwdriver with a strong handle made of good steel, which will ensure reliable clamping of the bolted contact connection;
3. Pliers;
4. Insulating material (duct tape).

Of course, all these rules and techniques apply to the connection and installation of household circuit breakers, as well as light switches. In industrial premises and conditions, connecting an automatic power switch is a laborious work associated with large-sized electrical devices, and there will already be needed socket and cap keys in order to reliably and efficiently mount the housing and the contact part. In everyday life, the phase voltage of 220 volts is most often used, which is the result of connecting to a three-phase circuit with a solidly grounded neutral. That is, in order to get this voltage equal to 220 volts, you need to connect to a phase conductive cable and to the neutral wire. Between the two phases, the voltage will already be 380 volts. Such voltage is used in everyday life most often in their own houses and cottages, when you need to connect a three-phase motor (compressor, fan, pump) without power loss.

Connecting a two-pole circuit breaker

Before connecting the circuit breaker, it is necessary to understand the purpose of this device, its functions and capabilities. An automatic two-pole circuit breaker is, by and large, two single-pole circuit breakers assembled in a single housing. According to the PUE, it is impossible to disconnect only one phase wire or zero, to ensure the safe operation of electrical installations.

This device has several protections:

• From a short circuit, that is, from a sharp increase in large currents that arise in this case in the circuit;
• From a prolonged increase in current more than the nominal, by a given and clearly advertised value.

That is, the machine will turn off in an emergency if, for example, it is designed for a working current of 20 A, and for 20 minutes, for example, 25 A will flow through it, a thermal relay will work in it, which may prevent re-closing. Only after the circuit breaker, or rather, its thermal relay, has cooled down to operating temperature, will it be possible to re-close it. And also the machine will turn off if a short circuit occurs in the outgoing circuit, that is, the one that went to consumers.

How to connect correctly

To connect the switch, you first need to decide on the source of energy, that is, where it will be powered from. The installation of circuit breakers in the shield will in any case also be carried out from the machine only with a higher rating.

But selectivity must be maintained. Selectivity is a well-established and selected mechanism for protecting devices in electrical circuits, as a result of which the circuit breaker is turned off in a given section of the circuit and it will be the closest to the place of a short circuit or overload. In other words, if the power supply system of an apartment or room is divided into several parts, then in the event of a short circuit in the circuits in the kitchen, only the machine that feeds this kitchen will turn off, and not the input to the entire apartment.

A source is known to which you can connect the upper contacts of the machine, now you need to decide whether it can withstand all the loads and all consumers that will be connected. Each electrical device has its own ratings:

1. Power consumption;
2. voltage;
3. Current strength.

Each of them is important, but sometimes only power and voltage can be indicated on some devices. You can also determine the approximate current strength yourself; for this, the power of the electrical appliance must be divided by its operating voltage. The automatic power supply should be selected in accordance with the sum of all devices that will be connected to it. For example, if there are three electrical devices that will consume 5 A each during their operation, then the circuit breaker should be slightly with a margin of 20–25 A. Then the flowing operating current will be 15 amperes, with the operating current of the machine 25. All devices will operate normally, without overheating. And in case of emergency, they will immediately turn off the entire circuit, thereby ensuring reliable fire safety of the premises. Polarity in AC voltage circuits does not matter, so there is no difference to which terminals the phase will be connected, and to which zero. In DC circuits, two-pole switches are also often used. One of the conclusions is negative, the other is positive, however, in domestic conditions, constant voltage is used very rarely.

Connecting a single-pole circuit breaker

A single-pole switch is designed to switch lighting circuits, or even sockets. The main advantage of bipolar is lower cost. The main thing in creating and supplying circuits connected through such a device is that it must necessarily break the phase wire, the zero one can be connected directly to the junction box.

Installing a circuit breaker

The modern installation of the switch is based on mounting it on a DIN rail or strip. This is the simplest and most effective attachment mechanism. Groups of circuit breakers, or single ones, must be installed in accordance with the rules for the safe installation of electrical installations in special shields that prevent dust from entering the machines, as well as accidental contact of a person with its conductive parts.

Be sure to remember that all installation, connection and installation work must be carried out safely, which means with a complete shutdown and a check for the absence of voltage. This event can be carried out by any probe or voltage indicator. It must be remembered that these works are classified as works of increased danger and can be the cause of human death.

The setting of the circuit breakers releases is made by the manufacturer, so it is better not to set up this system in a domestic environment.

Connecting a luminaire to a switch

Connecting a switch to a lighting fixture is a simple process, most importantly, you need to remember one basic rule that it is installed on a phase wire, and not on a zero one. To do this, when the power supply is turned on, you need to determine which wire is the phase. For this, special devices are used:

1. voltage indicators;
2. index screws.

In order to connect the switch, it is necessary to remove the supply voltage from this section of the circuit.

But it is also necessary to ensure that there is no connection of copper and aluminum wires by twisting, but only through a terminal block or connector. The combination of these two materials over time leads to poor contact between them due to the oxidation that results from the chemical reaction of these elements. The switch can be:

1. Single key;
2. Two-key;
3. Three-key, etc.

In any case, the phase wire comes to them alone, and after that it diverges as a control wire for different lamps of the lamp. Twisting in junction boxes must be reliably and efficiently insulated so that a short circuit does not occur.

Lighting switches must be selected in accordance with the current, which depends on the power of the lamps. On all these elements and components of the electrical network, if you look closely, there is a marking. For example, if you connect a light switch rated for 10 A, then the lamp current should not be more than this value, it may be less. Often, the current is not written on the lamps, but only the power and voltage. The current will be equal to the power divided by the voltage. For example, if a 100 W lamp is connected to a 220 Volt network, then the current in its circuit will be approximately 0.45 A.

The right choice, connection and installation of an automatic switch and a light switch is the key to a durable and uninterrupted operation of electrical equipment. And also in emergency cases, overloads and short circuits, the operation of the protection will protect the room from fires.

Video about circuit breakers

(may also be called an automatic machine, a switch) - a switching device designed to supply email. current to the object and its shutdown in automatic mode in the event of a malfunction in the electrical network. ProductsDesign and principle of operation

In order to properly connect the machine to work, it is necessary to understand its design and the principle of operation.

Sectional view of a circuit breaker with a thermal release

The main parts of the product are as follows:

• frame;
• switching device;
• control mechanism (handle, button);
• arc quenching chamber;
• screw terminals (top, bottom).

The housing and control mechanism are made of durable plastic, which does not support combustion. Switching device - these are contacts, both movable and fixed. The pole of the machine is a pair of these contacts, which has its own arc chute. Its main purpose is to extinguish email. an arc that appears at the moment of breaking contacts under load. It is a set of steel plates with a special profile shape. They are equidistant from each other and isolated from each other. The electric arc that has arisen in the process of malfunctions is attracted to these plates. Here it cools down and goes out. The number of pairs of contacts can be from 1 to 4.

For example, a two-pole circuit breaker has 2 moving and 2 fixed contacts. The machine has a position indicator: red means that the product is on, and green means it is off. This allows you to quickly navigate and find out what state the machine is in.

From the outside, only the handle, screw clamps located above and below, and an indicator are visible on the machine. Everything else is inside the device case.

The case has special jaws called a retainer, which allows you to quickly install the circuit breaker on a special rail called DIN. In case of replacement of the product, the same latch allows you to quickly dismantle it: by loosening the fixing screws on the terminals of the machine, it is enough to move the latch down. The machine will effortlessly be removed from the rack. Today, such rails are an integral part of any electrical panel. Many modern elements of electronics and automation are made specifically for installation on a DIN rail.

The mechanism that turns off the circuit breaker in case of emergency is called a release. Each type of release has its own device.

The thermal release in its design has a special plate called bimetallic. It is made by pressing from 2 dissimilar metals, which have different coefficients of linear expansion. The plate is connected to the electrical circuit in series with the load. During the operation of the device, the plate is heated by the current passing through it, and it bends towards the metal, which has a lower expansion coefficient. With an increase in current above the nominal (overload), its bending will turn off the machine. For this, a trigger mechanism is provided in the design.

The operation of the circuit breaker is also influenced by the ambient temperature. Therefore, in some products, the response time is adjusted according to this temperature. In any case, the higher the current value from the rated value, the faster the thermal release trips. Some of them work in a matter of fractions of a second.

Sectional view of a circuit breaker with a magnetic release

A coil with a winding and a core is the magnetic release. The winding is made of insulated copper wire. Included in email the circuit is in series with the contacts - the load current flows through it. If it exceeds the set permissible value, then the magnetic field of the coil will move the core, and it, in turn, acts on the disconnecting device. This will cause the circuit breaker contacts to open.

The device of the machine with a combined type of control

Some types of switches provide time delay in case of short circuit and they are called selective. Such a product has a special panel where the switch off time is set. This makes it possible to turn off a specific section where a short circuit occurred and where other automata worked. As a result, there is no need to completely disconnect the object from the power supply, it is possible to disconnect only the area where the emergency situation has developed. As a rule, these are powerful devices with a semiconductor type release.

The design of the machine may not have a release, and then it is called a switch-disconnector.

Machine selection

Before proceeding with the installation, it is necessary to choose the right product. How much to deliver: one or several, for what power, what manufacturer? Do you need an introductory machine? Connect before the counter or after? These are the most frequently asked questions.

Each switch is characterized by the following parameters:

• rated current (indicated in A);
• working voltage el. networks (indicated in B);
• the number of poles;
• maximum short-circuit current;
• time-current characteristic (the response time of the device depending on the magnitude of the flowing current - the limiting switching capacity (PKS)).

The last parameter is indicated in numbers, which mean at what current value the device will remain operational. In everyday life, products are used that have the numbers 4500, 6000 and 10000 A.

Manufacturers usually indicate all this directly on the body of the device, including a circuit diagram for switching on and a switch symbol.

Placement of the technical characteristics of the machine on the body of the device

The choice of the switch is carried out according to the load power and the cross section of the connected wire. They usually choose according to 2 parameters: overload current, short-circuit tripping current.

Overload occurs when devices and devices are connected to the network, the total power of which will lead to excessive heating of conductors and contact connections. Therefore, the machine that will be installed in a particular circuit must have a tripping current greater than or equal to the calculated one. It is determined by summing up the power of electrical devices intended for use (indicated in the passport). Next, the resulting figure is divided by 220 (recall physics and Ohm's law) and the desired overload current is obtained. It is also necessary to take into account one circumstance: this current should not be greater than the current that can flow through the conductor.

Short-circuit breaking current - this is its value at which the circuit breaker turns off. It is also calculated, and then selected according to the type of protection. It contains the values ​​​​of the tripping current in relation to the probable short-circuit current. This current depends on the type of load on the mains. In everyday life and for small objects, devices with the symbol B, C are used, and at the input - D (see the placement of the designation in the figure).

Most often, in addition to automata for each group line, the electrical circuit also includes an introductory automaton, an RCD or a differential automaton.

Connection diagram of protection devices in the switchboard

The diagram indicates the following main points that are important to know:

• a complete set of a switchboard (introductory machine, electric meter, RCD, machines from walking lines);
• paired operation of the introductory machine and RCD (this is evidenced by the lower rated current of the RCD than that of the introductory machine);
• installation location of the RCD (should be close to the power supply, therefore it is mounted immediately behind the meter);
• installation of one RCD that protects the entire electrical circuit (leakage current should not exceed 30 mA);
• when installing the RCD, the zero protective (PE - black lines) and the zero working conductor (N - blue lines) are separated;
• cross-section of conductors and brand of wire;
• how the phase conductor is connected to the main devices of the circuit (in the diagram, the lines are red).

The appearance of the switchboard with installed devices for metering the consumption of electricity. energy and protection e. circuits shown in the figure below:

Placement of protection elements and a meter in a switchboard

Manufacturers

Circuit breakers are manufactured in many countries. The main requirement for this device is that it must be made of quality materials and have a long service life. The price of a machine of the same power can vary quite widely and depends on the manufacturer.

The following companies produce the highest quality machines:

• French: Legrand, Schneider Electric, Hager;
• Slovak SEZ Krompachy;
• German: ABB, Moeller, Kopp;
• American General Electric;
• Russian: Contactor, KEAZ.

Mounting

Before mounting the switch, it is necessary to clearly determine where to connect the wires or power cable correctly: from above or below the product, or, more simply, to moving or fixed contacts. And although many do not comply with this condition and connect without taking this factor into account, it is still more correct to refer to the PUE, which for electricians is the document whose instructions must be followed. It clearly says: the connection of the supply wire (cable) must be carried out to the fixed contacts. They are in all modern machines are on top.

Installation cannot be carried out without tools and control devices. Must have:

• Screwdriver Set;
• mounting knife;
• tester or screwdriver with indicator.

single pole

Installation is carried out in single-phase networks, in which the input is made with 2 wires (usually these are old buildings): phase (L) and zero (PEN), i.e. made according to the TN-C system. The power wire is connected to terminal 1 of the machine, from terminal 2 through the meter it is distributed to machines of specific groups. Zero feeding through the counter is supplied to the PEN zero bus. This is clearly shown in the figure below.

Wiring diagram for single-pole circuit breakers in the switchboard

Bipolar

Installation is carried out in single-phase networks, in which the input is carried out by 3 wires, one of which is phase (L), the second is zero (N), the third is earth (PE), i.e. connection is carried out via TN-C-S or TN-S systems. Here the supply wire is connected to terminal 1, zero to terminal 3 and securely fastened. Terminal 2 is the output, the phase passes through the electricity meter. The input device, which is the RCD, distributes power evenly across the switches, combined into separate groups. From terminal 4, which is the output, zero passes through the electric meter, RCD and is connected to the N bus. The wiring is schematically shown in Figure 10.

Connection diagram in the shield of two-pole circuit breakers

The passport for the machine indicates the requirements for connecting conductors to its terminals. The information must be carefully reviewed. This applies to both the cross section and the type of connection of the conductors, as well as the length of the stripped part.

Usually, for machines used in everyday life, the wires are stripped of insulation to a length of up to 1 cm using a mounting knife. It is also necessary to pay attention to the color coding of the wires. White or brown for the supply wire (phase), blue (blue, black) for the neutral conductor, yellow-green or green for the ground wire.

After stripping with a mounting knife, the bare part of the wire is inserted into the terminal clamp from above or below, depending on which conductor is connected (phase, ground or zero). Then they are securely fixed into the corresponding terminals with screws. Here you will need a screwdriver. The reliability of the fastening of the conductor is checked by twitching. In the case of connecting a flexible wire to the circuit breaker, it is necessary to use special lugs, which makes the connection more reliable.

When connecting conductors to the machine, it is necessary to follow the following factors:

• insulation must not get under the contact clamp;
• do not overtighten, as this may deform the housing and, as a result, lead to device failure, malfunction or shortened service life.

In many cases, several circuit breakers are installed in the switchboard. Inexperienced electricians connect them together with jumpers. This is acceptable, but it is better to use a special tire. It's called a comb. It is usually cut to the required size, and then the phases are connected to the machines in the sequence provided for by the principal email. scheme.

Connection bar appearance

Electrification

To properly electrify an object of any complexity, you must perform the following steps:

• draw up an electrical circuit taking into account all the features of the electrical wiring of a particular object;
• correctly determine the total power consumption;
• determine the number of electrical groups and the power of each group;
• determine the installation location of the switchboard and how many modules it should be;
• choose a metering device (electric meter);
• correctly connect the outgoing and incoming lines;
• to connect the shield to the networks of the energy supply company.

Connection. Video

You can learn about the electrical circuit for connecting circuit breakers from the video below.

All this can only be done by competent electricians who are well versed in the power supply of simple and complex objects. They know the modern electrical base and are able to complete the electrical panel with everything necessary at minimal cost. In addition, based on many years of experience, they can provide useful advice on saving energy and improving the supply of electricity to existing facilities.

The process of installing machines in the electrical panel is quite simple and does not take much time. The only problem is to do everything right, because when connecting the wires, many novice electricians make small mistakes that can damage the device in a short period of time. In this article, we will look at how to connect a circuit breaker with our own hands, providing installation rules, basic errors and diagrams.

Typical installation errors

Most often, when, and in particular connecting the machine, the following errors are made:

Another important point, on the topic of which there are many discussions, is it possible to connect the machine in front of the electricity meter, or is it done only after it? The answer is that it is possible, and even necessary, the main thing is to buy a special box, which is sealed by energy sales representatives. Installing an introductory machine in front of the electric meter will allow you to safely replace the electricity control device in both a private house and an apartment.

Here, in fact, there are rules for installing and connecting an electric machine with your own hands. Now let's move on to the main topic of the article.

Main process

So, in the initial position, we have an electrical panel in which the products will be installed, as well as all the wires (input and outgoing to consumers).

Consider the instructions for dummies using the example of connecting a two-pole circuit breaker in a shield:

1. The first step is to turn off the electricity and check its presence with a multimeter or an indicator screwdriver. we provided readers!
2. The machine is installed on a special landing DIN-rail and latched with a latch. You can do without a din rail, but it's less convenient.
3. The cores of water and outgoing conductors are stripped by 8-10 mm.
4. In the two upper clamps, you need to connect the input zero and phase (do not forget about the recommendations above).
5. Accordingly, outgoing zero and phase are fixed in the two lower holes (those that go to electrical appliances, sockets and switches).
6. After that, the place must be checked manually for reliability. To do this, you need to carefully take the conductor and move it in different directions. If the core remains in place, then the connection is reliable, otherwise be sure to tighten the screw again.
7. After all electrical installation, the robot is supplied with voltage to the network and the performance of the product is checked.

That's the whole instruction for connecting a circuit breaker in a single-phase circuit. As you can see, there is nothing complicated, you just need to be careful. We also recommend that you familiarize yourself with the video tutorial, in which the connection process is discussed in more detail:

Visual video instruction

Installation of a low-quality single-pole machine

Wiring diagrams

Content:

Circuit breakers, called automata or switches in everyday life, refer to the means of switching and are intended to supply electric current to an object. The main function of these devices is to automatically turn off the power supply in the event of an emergency and network problems. The machine protects the electrical circuit from short circuits, overloads and voltage drops beyond the permissible value.

Which circuit breaker to install?

When calculating the rating of the circuit breaker, start from the wire section, temperature load, as well as how the wiring will be laid - hidden or open. Take into account not the limiting current transmission, but “calm”, i.e. there should be a good margin of safety, or, more simply, so that the conductor does not heat up due to the overestimated rating of the machine. In another case, if the conductor has a large bandwidth, it is not worth underestimating the face value of the machine - it will constantly kick out.

Sectional circuit breakers are "planted" on a plate called a din rail built into the switchboard. Circuit breakers are 1P (pole), 2P, 3P, 4P. The last two are installed in a three-phase network. In a single-phase 2P network, the machine is most often installed at the input.

The nominal current strength of circuit breakers in everyday life: 2A, 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A.

Where are circuit breakers not installed?

They put 1P on separate groups, 2P is possible, but this is not economical both in terms of money and in the space of the switchboard. It is known that in France, according to the rules and regulations, only two-pole switches are installed. It cannot be said that they do not save space in the control room. The fact is that, French two-pole switches are like our single-pole ones. The 1P circuit breaker must not be set to zero. Breaking zero separately from the phase is not recommended. All neutral conductors are attached to a common zero bus. You can break zero at the same time as the phase, in this case you need to set a 2P automaton.

To effectively protect your home's electrical circuit, consider replacing fuses or plugs, into a safer, more reliable and more cost-effective circuit breaker.

The process of installing machines in the electrical panel is quite simple and does not take much time. The only problem is to do everything right, because when connecting the wires, many novice electricians make small mistakes that can damage the device in a short period of time. In this article, we will look at how to connect a circuit breaker with our own hands, providing installation rules, basic errors and diagrams.

Typical installation errors

Most often, when, and in particular connecting the machine, the following errors are made:

Another important point, on the topic of which there are many discussions - is it possible to connect the machine in front of the electricity meter, or is it done only after it? The answer is that it is possible, and even necessary, the main thing is to buy a special box, which is sealed by energy sales representatives. Installing an introductory machine in front of the electric meter will allow you to safely replace the electricity control device in both a private house and an apartment.

Here, in fact, there are rules for installing and connecting an electric machine with your own hands. Now let's move on to the main topic of the article.

Main process

So, in the initial position, we have an electrical panel in which the products will be installed, as well as all the wires (input and outgoing to consumers).

Consider the instructions for dummies using the example of connecting a two-pole circuit breaker in a shield:

1. The first step is to turn off the electricity and check its presence with a multimeter or an indicator screwdriver. we provided readers!
2. The machine is installed on a special landing DIN-rail and latched with a latch. You can do without a din rail, but it's less convenient.
3. The cores of water and outgoing conductors are stripped by 8-10 mm.
4. In the two upper clamps, you need to connect the input zero and phase (do not forget about the recommendations above).
5. Accordingly, outgoing zero and phase are fixed in the two lower holes (those that go to electrical appliances, sockets and switches).
6. After that, the place must be checked manually for reliability. To do this, you need to carefully take the conductor and move it in different directions. If the core remains in place, then the connection is reliable, otherwise be sure to tighten the screw again.
7. After all electrical installation, the robot is supplied with voltage to the network and the performance of the product is checked.

That's the whole instruction for connecting a circuit breaker in a single-phase circuit. As you can see, there is nothing complicated, you just need to be careful. We also recommend that you familiarize yourself with the video tutorial, in which the connection process is discussed in more detail.

A modern switchboard in a home should be equipped with safety features such as a circuit breaker. To properly connect the machine in the shield, you need to know the rules and features of the procedure.

[ Hide ]

What is a circuit breaker and what is it for?

The circuit breaker is a small lever installed in the shield. The principle of its operation is that it allows you to turn off the electricity supply manually or automatically.

Automatic shutdown is necessary in the following cases:

• short circuit;
• overload of electric current supply.

In other words, such devices turn off electricity at a current exceeding the short circuit power.

Classification

Before buying a circuit breaker, an electrician must decide on the number of poles. This indicator depends on the phases of the network.

Automata are divided by the number of poles:

• single-pole;
• bipolar;
• three-pole;
• four-pole.

Single-pole and two-pole machines are installed in a single-phase network. Three-pole and four-pole are suitable for a three-phase network.

The growmir channel talks about self-installation and connecting the machine to the bag.

How to choose a machine?

The correct choice of the machine for the shield is a guarantee of the balanced operation of the entire electrical circuit in an apartment or other room.

• Legrand;
• hager;
• Merlin Green;
• Schneider Electric;

When buying a circuit breaker, experts recommend paying attention to the label, which contains all the information about the product.

When planning the choice of device, you need to pay attention to the parameters:

1. The value of the rated current. The higher it is, the more voltage is required to automatically turn off the machine. The parameter is selected based on the cable section, and not on the load power.
2. Number of poles. This parameter is selected based on the number of phases. The number of places for machines corresponds to the number of poles.

Do-it-yourself installation of a circuit breaker in an electrical panel

When installing the machine in an electrical panel, you need to focus on the rating of the device and the cable cross-section, which is determined based on the maximum wiring load.

Before installation evaluate:

• rated voltage of the network;
• maximum current;
• rated current.

To calculate the load, add up the total power of energy consumers (sockets, household appliances, etc.) and calculate the current power according to the formula below. Knowing this parameter, they decide which automata to attach.