Two-pole and three-pole switches: purpose, characteristics, installation features

General properties of switches

Regardless of how many poles in the switch, they perform one task - they protect the power grid from short circuits in an emergency. Even 2 devices structurally combined in one box work on the same principle.

An open circuit occurs when the rated current is exceeded. Power off is possible if the circuit is overloaded or there is a risk of a short circuit. The contact is immediately set in motion by the thermal distributor, which blocks the flow of current. The devices have changed fuses while remaining compact, easy to operate, but significantly superior in reliability to their outdated counterpart.

A 3-pole machine can be used not only in a three-phase network

When assembling a switchboard for a three-phase network, 3-pole circuit breakers are used. In the event of an overload of the network or in the event of a short circuit, such an automatic machine will unhook three phases at once.

How many poles are

Single-pole, two-pole, three-pole and four-pole circuit breakers

In the switchboard of an apartment or house, single-pole circuit breakers are most often used. Their task is to disconnect the phase conductor, thereby interrupting the supply of electricity to the circuit.Differential circuit breakers and RCDs turn off both the phase and the working zero at the same time, because. their operation may be due to a violation of the integrity of the wiring. The introductory machine in such a shield must always be bipolar.

Three-phase current is used by enterprises to power powerful units that require a voltage of 380 volts. Sometimes a four-core cable (three phases and a working zero) is brought to a residential building or office. Due to the fact that these rooms do not use equipment designed for such a voltage, the three phases are separated in the switchboard and a voltage of 220 is obtained between each phase and the working zero.

For such shields, 3-pole and four-pole circuit breakers are used. They work when the rated load is exceeded on any of the three wires and turn them off all at the same time, and in the case of a four-pole one, the working zero is additionally turned off.

Why use two and four poles

The introductory circuit breaker must necessarily completely turn off all phases and working zero, because. one of the wires of the input cable may be leaking to zero and if it is not disconnected using a 1-pole or 3-pole circuit breaker, there is a risk of electric shock.

Leakage with 3-pole circuit breaker

The figure shows that in this case, the entire working zero in the network is energized. If you use an introductory machine that cuts off the phase and zero, this can be avoided, therefore the use of four-pole and two-pole circuit breakers for three-phase and single-phase electrical networks is safer.

Diagram of a 3-pole circuit breaker

Each 3-pole machine is three single-pole ones that work simultaneously. One phase is connected to each terminal of a 3-pole circuit breaker.

Diagram of a 3-pole circuit breaker

As can be seen from the diagram, each circuit has a separate electromagnetic and thermal release, and separate arc extinguishers are provided in the case of a 3-pole machine.

A 3-pole circuit breaker may also be used in a single-phase power supply. In this case, phase and neutral wires are connected to two terminals of the switch, and the third terminal remains empty (signal).

Video about the polarity of switches and connection methods

The video will be useful for beginners who want to understand the differences and functionality of single-pole, double-pole, 3-pole and 4-pole circuit breakers. How to connect them correctly and in what cases one or another machine should be used.

How to choose a bipolar

To choose a good protective device, you should focus on the cross-sectional area of ​​\u200b\u200bthe connection wire. To do this, you need to calculate the value.

First you need to calculate the power and current of the equipment on the power line from the machine. For the current in the circuit, the formula I \u003d P / 220 is used, where 220 is the rated voltage, I is the current (A), P is the power (W).

Next, select the type of wire, focusing on the table.

Current strength, A	Network power, W	Cross section of copper wire	Cross section of aluminum wire
1	0,2	1	2,5
2	0,4	1	2,5
3	0,7	1	2,5
4	0,9	1	2,5
5	1,1	1	2,5
6	1,3	1	2,5
8	1,7	1	2,5
10	2,2	1,5	2,5
16	3,5	1,5	4
20	4,4	2,5	6

Focusing on the data obtained, you can choose the machine, taking into account the thermal inertia during heating.

On what principle does a single-pole machine work

Circuit breakers, as switching devices, perform the functions of conducting the permissible electric current and turning off the power if the rating is exceeded, which protects the electrical network from overload.

The task of a single-pole device is to protect the circuit in one wire. The operation of the device is concentrated on 2 switchgears - thermal and electromagnetic. When the increased load acts for a long time, the circuit is switched off by the first mechanism. If a short circuit occurs, the second distributor immediately cuts off the power supply.

Thermal protection is performed by a plate made of composite material according to the following principle:

1. A current exceeding the allowable level is received.
2. The bimetal heats up.
3. Curves.
4. Pushes the lever.
5. Turns off the device.
6. The plate is cooling down.

When the state of the bimetal returns to normal, it returns to its original state and the device can be reconnected. The composition of the electromagnetic device includes a coil, in the middle of which a core was placed.

Here is the picture:

1. A short circuit current occurs.
2. Enters the winding.
3. The force generated by the electromagnetic field moves the core.
4. Turns off the device.

In the course of interactions of physical processes, the opening of power contacts occurs, which de-energize the conductor.

An electric arc is created with a high current strength, it is directed into a chamber with parallel metal plates for crushing and complete disintegration. The machine can be turned off by simply turning the knob. Such switches are used in ordinary apartments, if only 2 wires are connected to the house. In a shed, a small private house, single-pole automata open the circuit.In apartment buildings there are grounding conductors, which means that only a two-pole is suitable.

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The difference between a two-pole and a single-pole machine

The difference between a single-pole and a two-pole circuit breaker is that in the first one, the technical parameters of several lines are monitored. Accordingly, the difference between two and three-pole is that in the first two are monitored, and in the second - three lines. At the moment of overvoltage in one device protects each line. The second device protects only one power line. At the same time, it is impossible to replace a two-pole machine with several single-pole ones because of the shutdown lever. The interlock is designed so that both lines will be disconnected in the event of a malfunction. In addition, the current will not evaporate. It will penetrate into a properly working device and a fire may occur.

The difference between a two-pole and a single-pole machine

Advantages and disadvantages

The advantages are reliable protection, power control capabilities, ease of installation and maintenance. The main advantage is the de-energization of several conductors, regardless of the occurrence of an accident in any of them. As a result, tension is completely removed.

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The disadvantages of a multi-pole protective device are the possibility of a cable breakdown by electric current during a simultaneous short circuit of several electrical networks.

Note! They also consist in turning off the power supply of the electrical wiring during a breakdown of the thermal release, the impossibility of turning on the power after an emergency line breakdown and sensitivity to mechanical damage.

Specifications

Technical characteristics of bipolar machines vary depending on the price and manufacturer. The rated voltage is 240 watts, the rated current is from 6 to 63 amperes, the number of poles is from 1 to 4, the time-current characteristic is designated B, C and D.

Technical characteristics of electrical equipment

Installation and wiring diagrams

A two-pole machine is installed according to the electrification plan. Before installation, the housing is checked for damage with deformations. The work of the shut-off handle must be of high quality. The installation takes into account the connection of a copper conductor with a lug, the connection of an aluminum cable with an end piece. Also taken into account is the upper group of fixed circuit breakers, conductor termination with insulating tubes and protective tape, the distance of the nodes and the location of the additional box.

The machine is placed on a part of the DIN rail. The latch bracket is removed with a flat screwdriver and placed on a rail with fasteners. During installation, the usual scheme is used. An introductory switch is placed before the counter, after it a two-pole type device is mounted, and a zero with a phase is connected from above. The wires lead to the chain from below. To connect multiple devices together, wired copper jumpers are used. The end is cleaned with a sharp object and crimped with a crimper.

Note! During the installation of the device, work must be carried out by two specialists in protective rubber gloves after obtaining permission from the housing and communal services. The connection must be made on the shield without damage at the attachment point.

Connecting circuit breakers

Switches S203 C are equipped with terminals: 35 mm + 10 mm (for devices up to 2 2 63A), and 50 mm + 10 mm 2 2 (for devices for 80, 100A) for separate connection of bus wiring and cable, - cylindrical bidirectional terminals with protection from improper installation, resistant to impact, which are available even after the installation of a modular machine. In the absence of bus wiring, it is possible to connect two pairs of conductors of different cross sections. S203 C have special clamping jaws for quick installation of the circuit breaker on a DIN rail located in switchboards, boxes and cabinets. In case of replacement of the product, the same lock allows you to quickly dismantle it. For ease of cable installation, the switches are equipped with captive screw technology, and the degree of finger protection in the connection area reduces the risk of electric shock and the possibility of a short circuit.

For whom and when are machines installed

A single-circuit electrical circuit is mainly used for the electrification of private houses, because there it is simply not advisable to protect the network with a two-terminal one.

A circuit breaker with one pole will completely cope with the task of protecting a circuit with homogeneous segments. Single-phase wiring, which provides a grounded neutral with neutral conductors shorted to the bus, will cost a single switch.

If the house has electrical appliances that receive energy from a transformer, they need an automatic machine with 2 poles. On such a current converter there is no phase and zero. When the current is cut off in one wire, it can flow through the other. The absence of voltage in 2 poles will protect equipment from short circuits and fires.

Bipolar switch: features and purpose

The main characteristic of all machines is the speed of shutdown in emergency situations and the ability to turn off. All circuit breakers can be triggered by 2 types of shutdown mechanism, namely: thermal and electromagnetic. The electromagnetic mechanism opens the voltage circuit when a short circuit occurs, and the thermal one turns off if the continuous load in the network exceeds the allowable limit.

Mounting the machine, which has 2 poles, makes it possible to control some parameters.

Namely:

• With such a machine, it is possible to control 2 electrical wiring circuits independent of each other, with their simultaneous shutdown in the event of a breakdown of any circuit;
• It is also possible to control the parameters of each of the circuits, but in the event of a failure of one of the circuits, the voltage supply to the second circuit is turned off;
• Control over DC lines that have a similar shutdown.

Based on such characteristics in the house, it is better to install a two-pole automatic machine, since in the event of a breakdown, such an automatic machine will de-energize not only a certain circuit, but also all electrical circuits in the house. With such a machine, you can perform a manual shutdown if you need it.

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A 3-pole machine can be used not only in a three-phase network

When assembling a switchboard for a three-phase network, 3-pole circuit breakers are used. In the event of an overload of the network or in the event of a short circuit, such an automatic machine will unhook three phases at once.

How many poles are

Single-pole, two-pole, three-pole and four-pole circuit breakers

In the switchboard of an apartment or house, single-pole circuit breakers are most often used. Their task is to disconnect the phase conductor, thereby interrupting the supply of electricity to the circuit. Differential circuit breakers and RCDs turn off both the phase and the working zero at the same time, because. their operation may be due to a violation of the integrity of the wiring. The introductory machine in such a shield must always be bipolar.

Three-phase current is used by enterprises to power powerful units that require a voltage of 380 volts. Sometimes a four-core cable (three phases and a working zero) is brought to a residential building or office. Due to the fact that these rooms do not use equipment designed for such a voltage, the three phases are separated in the switchboard and a voltage of 220 is obtained between each phase and the working zero.

For such shields, 3-pole and four-pole circuit breakers are used. They work when the rated load is exceeded on any of the three wires and turn them off all at the same time, and in the case of a four-pole one, the working zero is additionally turned off.

Why use two and four poles

The introductory circuit breaker must necessarily completely turn off all phases and working zero, because.one of the wires of the input cable may be leaking to zero and if it is not disconnected using a 1-pole or 3-pole circuit breaker, there is a risk of electric shock.

Leakage with 3-pole circuit breaker

The figure shows that in this case, the entire working zero in the network is energized. If you use an introductory machine that cuts off the phase and zero, this can be avoided, therefore the use of four-pole and two-pole circuit breakers for three-phase and single-phase electrical networks is safer.

Diagram of a 3-pole circuit breaker

Each 3-pole machine is three single-pole ones that work simultaneously. One phase is connected to each terminal of a 3-pole circuit breaker.

Diagram of a 3-pole circuit breaker

As can be seen from the diagram, each circuit has a separate electromagnetic and thermal release, and separate arc extinguishers are provided in the case of a 3-pole machine.

A 3-pole circuit breaker may also be used in a single-phase power supply. In this case, phase and neutral wires are connected to two terminals of the switch, and the third terminal remains empty (signal).

Video about the polarity of switches and connection methods

The video will be useful for beginners who want to understand the differences and functionality of single-pole, double-pole, 3-pole and 4-pole circuit breakers. How to connect them correctly and in what cases one or another machine should be used.

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Next you need to connect the wires. You should strictly adhere to the scheme. The input wires of the phase and zero are suitable from the top of the two-pole machine, and the wires are led from the bottom into the circuit

It is important not to confuse: the entrance is from above, the exit is from below, otherwise the machine may fail and will not perform its functions

How to properly install circuit breakers in the electrical panel?

The machines can be connected using jumpers made of copper wire of the same cross section as the circuit wire. Jumpers are required to connect two-pole machines in a row. And also with the help of combs - these are insulated tires, used to connect single-pole machines.

The ends of the wires are stripped using a special stripper tool or a sharp knife. Then they are crimped with cable lugs with a crimper hand tool. If there is no such equipment, then you can simply tin the ends with a soldering iron using rosin and tin. When connecting wires to machines, it is necessary to tighten the bolts tightly with a screwdriver so that weak contact does not cause heating and damage to conductive materials.

The ground wire always passes by the machines straight from the ground bus. Zero wires are connected to the zero bus.

Circuit breaker device

For this, a special latch is provided on the back of the machine.In the event that the machine trips, the voltage remains only on the upper contacts, this is completely safe and is provided for by the circuit breaker connection diagram.

We measure the required amount of ground wire, bite off the excess, remove the insulation 1 centimeter and connect the wire to the contact.

The larger the cable cross-section, the higher the permissible continuous current. Multi-pole machines are assembled from several single-pole ones. By the way, here is the system for connecting the machine below.

It is necessary to choose an automatic machine with the nearest large value of the rated current. The housing version of the two-pole switch allows mounting on a standard DIN rail. A modified device for three phase poles with an additional zero pole.

Two-pole automatic machine: installation, wiring diagram

They disconnect zero and phase from the protected section of the circuit and allow repair, maintenance or replacement of circuit breakers. Bipolar machines - in what cases are they used?

Another difference is the ability to use in conjunction with complex equipment. The presence of a magnetic flux in the core activates the appearance of a current in the secondary winding, which contributes to the operation of the protection mechanism.

Two outgoing, they are located below the machine. Recommended materials on the topic: Let's decide on the connection colors: blue wire - always zero yellow with a green stripe - earth the remaining color, in our case black, will be the phase Phase and zero are connected to the terminals of the machine, the earth is separately connected to the through terminal. We remove the second layer of insulation from the phase and neutral wires, about 1 centimeter.

This is what it looks like in the end. Combustion gases are removed from the inside through a special channel.This is the same blocking device that was discussed above. The top contact pair is designed for connection of phase and neutral wires. However, there is a special type of device that is the first obstacle on the way from the substation to the object.
Circuit breakers polarity and connection diagrams

On what principle does a single-pole machine work

Circuit breakers, as switching devices, perform the functions of conducting the permissible electric current and turning off the power if the rating is exceeded, which protects the electrical network from overload.

The task of a single-pole device is to protect the circuit in one wire. The operation of the device is concentrated on 2 switchgears - thermal and electromagnetic. When the increased load acts for a long time, the circuit is switched off by the first mechanism. If a short circuit occurs, the second distributor immediately cuts off the power supply.

Thermal protection is performed by a plate made of composite material according to the following principle:

1. A current exceeding the allowable level is received.
2. The bimetal heats up.
3. Curves.
4. Pushes the lever.
5. Turns off the device.
6. The plate is cooling down.

When the state of the bimetal returns to normal, it returns to its original state and the device can be reconnected. The composition of the electromagnetic device includes a coil, in the middle of which a core was placed.

Here is the picture:

1. A short circuit current occurs.
2. Enters the winding.
3. The force generated by the electromagnetic field moves the core.
4. Turns off the device.

In the course of interactions of physical processes, the opening of power contacts occurs, which de-energize the conductor.

A small life hack on how to choose the right switch for your home

We offer some general recommendations:

• Based on all of the above, we should opt for AB with a time-current characteristic "C".
• When choosing standard parameters, it is necessary to take into account the planned load. To calculate, you should use Ohm's law: I \u003d P / U, where P is the power of the circuit, U is the voltage. Having calculated the current strength (I), we select the value of AB according to the table shown in Figure 10.

  Figure 10. Graph for selecting AB depending on the load current Let's tell you how to use the graph. Suppose, after calculating the load current, we got the result - 42 A. You should choose an automatic machine where this value will be in the green zone (working area), it will be nominal - 50 A. When choosing, you should also consider what current the wiring is designed for . It is allowed to select the machine based on this value, provided that the total load current is less than the rated current for wiring.

• If it is planned to install an RCD or a differential current machine, it is necessary to provide grounding, otherwise these devices may not work correctly;
• It is better to give preference to products of well-known brands, they are more reliable and last longer than Chinese products.

How to choose according to the characteristics and functions of the device

The main parameter by which the circuit breaker is selected is the total current load from all connected electrical appliances

You also need to pay attention to other factors - the mains voltage, the number of poles, the security of the case, the cross section of the wires, the condition of the electrical wiring.

Determining the polarity of the machine

Depending on the type of wiring, the pole of the machine is selected. For single-phase networks, one- and two-terminal networks are used; for a three-phase electrical network, devices with three and four poles are used.

Current selection

Current is the most important characteristic that affects the choice of the machine. It depends on this indicator whether the protection will work in an emergency. For electrical panels located near electrical substations, a 6 kA protective device should be purchased. In residential premises, this value increases to 10 kA.

Operating or rated current

Operating currents are determined by the total load of all household appliances that the machine protects. The cross-section of electrical wires and their material should also be taken into account.

For the lighting group, 10 Amp machines are usually used. Sockets can be connected to 16 amps. Powerful household equipment such as electric stoves and water heaters require 32 A from the protective circuit breaker.

The exact value is calculated as the total power of all household appliances divided by 220 V.

It is undesirable to greatly overestimate the operating current - the machine may not work in case of an accident.

Short circuit current

To select the machine for the short circuit current, you should use the rules of the PUE. It is forbidden to use circuit breakers with a breaking capacity below 6 kA. In homes, 6 and 10 kA devices are most often used.

Selectivity

This term refers to the shutdown in an emergency of only the problematic section of the power grid, and not all the energy in the house. You should select machines for each group of devices separately. The introductory machine is selected at 40 A, then devices with a lower current are placed for each type of household device.

Number of poles

There are several types of machines: single-pole, two-pole, three-pole and four-pole. Single terminals are used in a single-phase network (one phase, two, three wires). The neutral in this case is not protected. Used for socket group or for lighting. The double pole switch is used for electrical wiring with one phase and two wires. It can be used as an introductory fuse for the entire network and for protecting individual electrical appliances. Devices with two poles are the most common.

Replacing one two-pole device with two single-pole devices is prohibited by the rules of the PUE.

Three-pole and four-pole are used in a three-phase network of 380 volts. They are spilled by the presence of a neutral wire in a device with four poles.

Cable section

The cross-section and material of the cables have a huge influence on the choice. Houses built before 2003 used aluminum wiring. It is weaker and needs to be replaced. It is impossible to install a new switch, selected only by the total power.

Copper cables carry more current than aluminum

Here it is important to take into account the cross section - copper products with an area of ​​\u200b\u200b2.5 sq. Mm. work safely with currents up to 30 A

To determine the desired value, use the tables for calculating the cable section.

Manufacturer

Be sure to pay attention to the manufacturer of the machine. It is better to purchase the device from a well-known trusted company in a specialized store

This will reduce the risk of buying a fake, and the purchased product will meet the stated criteria. Also, company stores give a guarantee for the switch.

Case protection degree

Each circuit breaker has its own degree of enclosure protection. It is written as IP and 2 digits. Sometimes 2 Latin letters can additionally be used to describe auxiliary characteristics. The first digit indicates the degree of protection against dust, the second - against moisture. The higher the number, the higher the security of the body of the machine.

Marking

The switch is marked with letters and numbers. It is decoded as follows:

• letter A, B, C, etc. - the class of the machine, means the limit of the current of instantaneous operation;
• the figure indicates the rated current at which the device operates in normal mode;
• a number in thousands of amperes is also indicated next to it, indicating the maximum current at which the switch will respond.

The marking is indicated on the body of the device and in the relevant documentation.

Application area

1. As introductory circuit breakers. This is the most popular application. With the simultaneous disconnection of the phase and zero, maximum safety is ensured when working in the circuit, because there is a complete blackout. In addition, according to the new rules of the Electrical Installation Device (clause 6.6.28, clause 3.1.18), the operation of single-pole automatic machines at the input is prohibited.
2. To protect a separate group of electricity consumers. Disabling the two-pole machine will prevent the RCD from tripping (residual current device - designed to protect against differential currents) if zero and phase are in erroneous contact during repair work in circuits under load. It also facilitates the search for a branch with a malfunction when the RCD is triggered by current leakage to the ground.
3. For protection and control of circuits with simultaneous power supply.For example, when a heat gun is connected, a phase is supplied to the heating elements through one pole of the machine, and a phase is supplied to the fan motor through the other pole. If one equipment is switched off, the other will be switched off, which will prevent the possibility of the heaters working without cooling.

We proceed to the connection of the circuit breaker

If there is voltage on your supply wire, it must be disconnected before work begins. Then make sure that there is no voltage on the connected wire using a voltage indicator. For connection, we use a wire VVGngP 3 * 2.5 three-core, with a cross section of 2.5 mm.

We prepare suitable wires for connection. Our wire is double insulated, with a common outer and multi-colored inner. Decide on connection colors:

• blue wire - always zero
• yellow with a green stripe - earth
• the remaining color, in our case black, will be the phase

Phase and zero are connected to the terminals of the machine, the ground is connected separately to the through terminal. We remove the first layer of insulation, measure the desired length, bite off the excess. We remove the second layer of insulation from the phase and neutral wires, about 1 centimeter.

We unscrew the contact screws and insert the wires into the contacts of the machine. We connect the phase wire on the left, and the zero wire on the right. Outgoing wires must be connected in the same way. Be sure to check again after connecting. Care must be taken to ensure that the wire insulation does not accidentally get into the clamping contact, because of this the copper core will have poor pressure on the contact of the machine, from which the wire will heat up, the contact will burn, and the result will be the failure of the machine.

We inserted the wires, tightened the screws with a screwdriver, now you need to make sure that the wire is securely fixed in the terminal clamp. We check each wire separately, swing it a little to the left, to the right, pull it up from the contact, if the wire remains motionless, the contact is good.

In our case, a three-wire wire is used, in addition to phase and zero, there is a ground wire. In no case is it connected through a circuit breaker; a through contact is provided for it. Inside, it is connected by a metal bus so that the wire passes without a break to its final destination, usually sockets.

If there is no pass-through contact at hand, you can simply twist the incoming and outgoing core with a regular twist, but in this case it must be pulled well with pliers. An example is shown in the picture.

The through contact is installed just as easily as the machine, it snaps onto the rail with a slight movement of the hand. We measure the required amount of ground wire, bite off the excess, remove the insulation (1 centimeter) and connect the wire to the contact.

Do not forget to make sure that the wire is well fixed in the terminal clamp.

Suitable wires are connected.

In the event that the machine trips, the voltage remains only on the upper contacts, this is completely safe and is provided for by the circuit breaker connection diagram. The lower contacts in this case will be completely disconnected from the electric current.

We connect the outgoing wires. By the way, these wires can go anywhere to a light, an outlet, or directly to equipment, such as an electric water heater or an electric stove.

We remove the outer insulation, measure the amount of wire required for connection.

We remove the insulation from the copper wires and connect the wires to the machine.

We prepare the ground wire. We measure the right amount, clean, connect. We check the reliability of fixation in contact.

The connection of the circuit breaker has come to its logical conclusion, all the wires are connected, you can apply voltage. At the moment, the machine is in the disabled down (disabled) position, we can safely apply voltage to it and turn it on, for this we move the lever to the up (on) position.

By connecting the circuit breaker with our own hands, we saved:

• calling a specialist electrician - 200 rubles
• installation and connection of a two-pole automatic switch - 300 rubles
• DIN rail installation - 100 rubles
• installation and connection of a through ground contact 150 rubles

TOTAL: 750 rubles

*The cost of electrical installation services is given from the pricing table

Automatic machines for a three-phase network

Three-phase input, gives some advantages, in comparison with single-phase. This is the possibility of using powerful energy consumers and the convenience of connecting electric motors.

Using such a network, it is important to evenly distribute the load between all three phases in order to eliminate voltage drops. It is desirable to use a four-pole inlet machine, and protect the outgoing lines with single-pole and three-pole machines

When choosing three-pole circuit breakers for protecting equipment with electric motors, pay attention to the overload capacity of the circuit breaker. To avoid false triggering of the protective device, use circuit breakers with characteristic "D"

What is the conclusion?

Each of the machines has its own advantages and disadvantages. Some are expensive, others are not as compact as the consumer would like. In any case, the choice of a switch depends on the load connected to the housing, the cross section of the conductors.

Which one is suitable for a particular house will be indicated by the marking applied to the body of the product. Work related to electrical wiring is best left to electricians, because despite innovations, no one has canceled the rule that everyone should mind their own business. The safety of all residents and the safety of property depends on properly connected electricity.

A special switching device is used to conduct currents under normal conditions and automatically switch off the voltage in cases of overload or short circuit. A two-pole machine is an electrical appliance with automatic phase and zero, i.e., two poles. At the moment of disconnection, the neutral and the phase are disconnected simultaneously. The equipment will be used for a single-phase network.

Conclusions and useful video on the topic

What are slot machines and how they differ can be found in the following video:

About the selection criteria for protective devices:

The reliability of automatic locking devices is often determined not by the brand, but by the correct selection, taking into account the workload. Also, a significant impact on the operation of devices has an accurate calculation of the cross section of the conductors that feed the load from the machine and the calculation of the cross section of the input cable. When all the nuances of installation are taken into account, even Chinese devices, which are several times cheaper than branded ones, work for quite a long period of time without any complaints.