Types of electric machines. The concept of an automatic device. Types of automatic devices used in modern industrial production. Machine type MA

Circuit breakers are devices that provide wiring protection under short circuit conditions, when a load is connected with indicators exceeding the set values. They should be chosen with special care. It is important to consider the types of circuit breakers, their parameters.

Automatic machines of different types

Characteristics of machines

When choosing a circuit breaker, it makes sense to focus on the characteristics of the device. This is an indicator by which you can determine the sensitivity of the device to a possible excess of current values. Different types of circuit breakers have their own marking - it is easy to understand from it how quickly the equipment will respond to excess current values ​​to the network. Some switches respond instantly, while others are activated over a period of time.

• A - marking, which is affixed to the most sensitive models of equipment. Automatic machines of this type immediately register the fact of overload and quickly respond to it. They are used to protect equipment characterized by high accuracy, but in everyday life they are almost impossible to meet.
• B - characteristic, which have switches that operate with an insignificant delay. In everyday life, switches with the appropriate characteristics are used together with computers, modern LCD TVs and other expensive household appliances.
• C - a characteristic of automata, which are most widely used in everyday life. The equipment begins to function with a slight delay, which is enough for a delayed response to registered network congestion. The network is turned off by the device only if it has a fault that really matters
• D is a characteristic of switches that have a minimum sensitivity to exceeding current indicators. Basically, such devices are used as part of the supply of electricity to the building. They are installed in shields, almost all networks are under their control. Such devices are selected as a fallback option, since they are activated only if the machine does not turn on in time.

All parameters of circuit breakers are written on the front

Important! Experts believe that the ideal performance of circuit breakers should vary within certain limits. Maximum - 4.5 kA. Only in this case, the contacts will be under reliable protection, and current discharges will be discharged in any conditions, even if the established indicators are exceeded.

Types of machines

The classification of circuit breakers is based on their types and features. As for the types, we can distinguish the following:

• Breaking capacity ratings - we are talking about the resistance of the contacts of the switch to the effects of currents with high rates, as well as to the conditions in which the circuit is deformed. Under such conditions, the risk of burning increases, which is neutralized by the appearance of an arc and an increase in temperature. The higher the quality and durability of the equipment material, the higher are its corresponding abilities. Such switches are more expensive, but their characteristics fully justify the price. Switches have a long service life, do not require regular replacement
• Rating calibration - we are talking about the parameters in which the equipment operates in normal mode. They are installed at the stage of equipment production, and are not regulated already in the process of its use. This characteristic allows you to understand how strong overloads the device can withstand, the period of time of its operation in such conditions
• Setpoint - usually this indicator is displayed as a marking on the equipment case. We are talking about the maximum current values ​​in non-standard conditions, which, even with frequent shutdowns, will not have any effect on the functioning of the device. The setting is expressed in current units, marked with Latin letters, digital values. The numbers, in this case, display the face value. Latin letters can be seen in the marking of only those machines that are made in accordance with DIN standards

Production automation- this is a process in the development of machine production, in which the functions of control and control, previously performed by a person, are transferred to instruments and automatic devices. The introduction of automation in production can significantly increase labor productivity and product quality, reduce the proportion of workers employed in various areas of production.

Before the introduction of automation tools, the replacement of physical labor took place through the mechanization of the main and auxiliary operations of the production process. Intellectual labor for a long time remained non-mechanized (manual). Currently, operations of physical and intellectual labor, amenable to formalization, are becoming the object of mechanization and automation.

Modern manufacturing systems that provide flexibility in automated manufacturing include:

CNC machines first appeared on the market in 1955. Mass distribution began only with the use of microprocessors.

Industrial robots first appeared in 1962. Mass distribution is associated with the development of microelectronics.

· Robotized technological complex (RTC), first appeared on the market in 1970-80s. Mass distribution began with the use of programmable control systems.

· Flexible production systems, characterized by a combination of technological units and computer-controlled robots, with equipment for moving workpieces and changing tools.

Automated warehouse systems Automated Storage and Retrieval Systems, AS/RS). Provide for the use of computer-controlled lifting and transport devices that lay products in the warehouse and remove them from there on command.

computer-based quality control systems Computer-aided Quality Control, CAQ) - a technical application of computers and computer-controlled machines for checking the quality of products.

· Computer-aided design system Computer-aided Design, CAD) is used by designers in the development of new products and technical and economic documentation.

Planning and linking individual elements of the plan using a computer (eng. Computer-aided Planning, CAP). SAR- is divided according to various characteristics and purposes, according to the state of approximately the same elements.

COMPUTER (electronic computer)

Outline the main provisions of the technology of cleaning and washing operations. Compare cleaning and washing equipment and justify its choice. Evaluate the possibilities of designing a cleaning and washing station.

Washing work is often carried out manually using a hose with a gun and a pump of low (0.3-0.4 MPa) or high (1.5-2.0 MPa) pressure or mechanized using washing installations. A progressive way is mechanized and automatic washing of cars, automotive components and parts, which allows you to replace manual labor as much as possible and increase labor productivity with high-quality washing.

So, consider the main existing types of car washes:

A hand wash is a traditional car wash performed by humans. The car is washed with water and car shampoo using sponges, brushes, rags, etc., that is, contact washing.

The advantage of a manual car wash is that a person in the process of work sees which areas are more polluted and need more thorough cleaning.

Cons: with such a wash, there is a high risk of damaging the paintwork on the car body; and hand washing the car will take the most time.

A brush car wash is a contact wash, in which people do not participate, it is carried out using special automatic installations. The process consists of several stages: first, the machine is washed with water under pressure, then with hot foam, then quickly rotating brushes are taken to clean the machine of dirt. The last step is to apply protective wax and dry the car.

A brush washer is suitable for tough dirt that a touchless washer might not be able to handle. Brushes are made of synthetic threads, rounded at the ends. High-quality brushes should not scratch the paintwork.

Touchless car wash is a wash with active foams. This technology is used in conventional non-contact car washes, where washing is carried out by people using special devices, as well as in conveyor and portal car washes. During such a wash, the main layer of dirt is washed off with a high-pressure water jet, then active foam is applied with special equipment, under the action of which the remaining dirt lags behind the body, and after a while the foam is also washed off with a stream of water under pressure. As a rule, such a wash ends with the application of a protective polish, which will give an attractive shine and protect against rapid pollution and the harmful effects of the environment.

A touchless car wash or pressure washer causes the least damage to the body paintwork.

Dry washing is washing with a special shampoo-polish. Motorists carry out such a wash with their own hands. This wash does not require water. Dry shampoo manufacturers claim that the silicone oil and surfactants (surfactants) in the shampoo soften, soak and coat dirt particles, ensuring the integrity of the paintwork in this type of washing. Dry washing for a while will provide shine and protection of the body from the effects of negative environmental factors.

The disadvantage of such a wash is the impossibility or inconvenience of processing hard-to-reach places in the car. Therefore, this type of washing is recommended to be used in between water washes to keep the car clean and tidy.

There are two types of automatic car washes:

Conveyor type (or tunnel). This is when the vehicle is slowly conveyed through several archways with various cleaning and rinsing functions (for example: pre-wash, wheel wash, underbody wash, high pressure wash, dryer).

The biggest plus of such car washes is the speed of work and high productivity. All arches work simultaneously, so the driver does not have to wait for the previous car to go through all the procedures.

portal type. With such a wash, the car is stationary, and the portal (washing arch) moves relative to it.

The disadvantage compared to the conveyor car wash is that the portal car wash is not able to quickly take such a number of cars.

Outline the main provisions of the technology of diagnostic work. Compare diagnostic equipment and justify its choice. Evaluate the possibilities of designing a post of diagnostic work

1.1. The Manual sets out the main provisions for organizing the diagnostics of the technical condition of the rolling stock of road transport in passenger cars, trucks, buses and mixed motor transport enterprises (ATP) of various capacities.

1.2. Technical diagnostics is part of the technological process of maintenance (TO) and repair (R) of vehicles, the main method for conducting control and control and adjustment work. In the ATP technical service management system, diagnostics is a subsystem of information.

1.3. The organization of vehicle diagnostics is based on the planned preventive maintenance and repair system in force in the USSR, set out in the "Regulations on the maintenance and repair of rolling stock of road transport."

1.4. In the conditions of ATP, technical diagnostics should solve the following tasks:

Refinement of failures and malfunctions identified during operation;

Identification of cars, the technical condition of which does not meet the requirements of traffic safety and environmental protection;

Identification of malfunctions before maintenance, the elimination of which requires labor-intensive repair or adjustment work in the current repair zone (TR);

Clarification of the nature and causes of failures or malfunctions identified in the process of maintenance and repair;

Forecasting the failure-free operation of units, systems and the car as a whole within the inter-inspection run;

Issuance of information on the technical condition of the rolling stock for planning, preparation and management of the production of maintenance and repair;

Quality control of the performed maintenance and repair works.

Vehicle diagnostic technology contains: list and sequence of operations, repeatability coefficients, labor intensity, category of work, tools and equipment used, technical conditions for the performance of work.

3.2. Depending on the shift program and the type of rolling stock, diagnostic work is carried out at separate posts (dead-end or through) or posts located in a line.

3.3. The technology is compiled separately for the types of diagnostics D-1, D-2 and others.

3.4. For specialized repair, adjustment and diagnostic posts, Dr technology is compiled for individual diagnosed units, systems and types of work (brake system, steering, wheel alignment, wheel balancing, headlight installation, etc.).

3.5. When developing a diagnostic technology, one should be guided by the established lists of diagnostic operations by types of diagnostics (Appendices 1, 2), which are part of the control work given in the current Regulations on the maintenance and repair of rolling stock of road transport, as well as a list of diagnostic features (parameters) and their limit values ​​(Appendix 5).

3.6. A typical diagnostic technology should contain preparatory work performed before diagnosing, proper diagnosing, adjustment and final work performed based on the results of diagnosing.

3.7. The diagnostic technology D-1 and D-2 is compiled taking into account the specific conditions of the ATP.

3.8. Diagnostics at the posts (lines) in the scope of D-1 and D-2 are performed by diagnostic operators or diagnostic mechanics. Drivers are attached to them to help them, who, in addition to driving cars in the process of diagnosing, are engaged in placing cars at diagnostic posts, removing them, distilling to the appropriate zone (storage, waiting, MOT and TR), as well as preparatory and some adjustment work . In the ATP, where there are no full-time ferry drivers, this work is assigned to the drivers of the vehicles being diagnosed or column mechanics who have the right to drive.

Control and diagnostic (Dr) and adjustment operations at the posts of maintenance and repair are carried out by repair workers.

3.9. At posts (lines) D-1 and D-2, repair work related to the elimination of identified malfunctions, as a rule, is not performed. The exception is adjustment work, the implementation of which is provided for by the technological process in the process of diagnosing.

3.10. Performing diagnostic operations before maintenance and current repairs is mandatory, regardless of the availability of diagnostic tools. In the absence of the latter in the ATP, the control and diagnostic operations provided for by this "Manual ..." are performed subjectively by a diagnostician in order to identify the necessary volumes of current repairs performed before maintenance.

When assembling a switchboard or connecting new large household appliances, a home master will definitely face such a problem as the need to select circuit breakers. They provide electrical and fire safety, so the right choice of machine is the key to the safety of you, family and property.

What is the machine for?

In the power supply circuit, an automatic machine is installed to prevent overheating of the wiring. Any wiring is designed for the passage of a certain current. If the passed current exceeds this value, the conductor starts to heat up too much. If this situation persists for a sufficient period of time, the wiring begins to melt, which leads to a short circuit. A circuit breaker is installed to prevent this situation.

The second task of the circuit breaker is to turn off the power when a short circuit current (SC) occurs. When closing, the currents in the circuit increase many times and can reach thousands of amperes. So that they do not destroy the wiring and do not damage the equipment included in the line, the circuit breaker must turn off the power as soon as possible - as soon as the current exceeds a certain limit.

In order for the protective circuit breaker to perform its functions properly, it is necessary to correctly select the machine in all respects. There are not so many of them - only three, but each one must be dealt with.

What are automatic protection

To protect the conductors of a single-phase 220 V network, there are single-pole and two-pole disconnecting devices. Only one conductor is connected to single-pole - phase, to two-pole and phase and zero. Single-pole machines are installed on 220 V internal lighting circuits, on socket groups in rooms with normal operating conditions. They are also put on some types of load in three-phase networks, connecting one of the phases.

For three-phase networks (380 V) there are three and four poles. These circuit breakers (the correct name is a circuit breaker) are put on a three-phase load (ovens, hobs and other equipment that runs on 380 V).

In rooms with high humidity (bathroom, sauna, swimming pool, etc.), bipolar circuit breakers are installed. They are also recommended to be installed on powerful appliances - on washing machines and dishwashers, boilers, ovens, etc.

It's just that in emergency situations - during a short circuit or insulation breakdown - a phase voltage can get to the neutral wire. If a single-pole device is installed on the power line, it will disconnect the phase wire, and zero with a dangerous voltage will remain connected. So, there is a possibility of electric shock when touched. That is, the choice of the machine is simple - single-pole switches are placed on some of the lines, and two-pole switches on some. The exact amount depends on the network condition.

For a three-phase network, there are three-pole circuit breakers. Such an automatic machine is installed at the entrance and at consumers, to which all three phases are connected - an electric stove, a three-phase hob, an oven, etc. The remaining consumers are equipped with bipolar circuit breakers. They must necessarily disconnect both phase and neutral.

An example of a three-phase network wiring - types of circuit breakers

The choice of the circuit breaker rating does not depend on the number of wires connected to it.

Deciding on a denomination

Actually, from the functions of the circuit breaker, the rule for determining the rating of the circuit breaker follows: it must operate until the current exceeds the wiring capabilities. And this means that the current rating of the machine must be less than the maximum current that the wiring can withstand.

Based on this, the algorithm for choosing a circuit breaker is simple:

• for a specific area.
• See what maximum current this cable can withstand (there is in the table).
• Further, from all the denominations of circuit breakers, we select the nearest smaller one. The ratings of the machines are tied to the permissible continuous load currents for a particular cable - they have a slightly lower rating (there is in the table). The list of ratings looks like this: 16 A, 25 A, 32 A, 40 A, 63 A. From this list, choose the right one. There are denominations and less, but they are practically not used anymore - we have too many electrical appliances and they have considerable power.

Example

The algorithm is very simple, but it works flawlessly. To make it clearer, let's look at an example. Below is a table that indicates the maximum allowable current for conductors that are used for. There are also recommendations regarding the use of machines. They are given in the column "Rated current of the circuit breaker". It is there that we are looking for denominations - it is slightly less than the maximum allowable, so that the wiring works in normal mode.

In the table we find the selected wire section for this line. Let us need to lay a cable with a cross section of 2.5 mm 2 (the most common when laying to medium power devices). A conductor with such a cross section can withstand a current of 27 A, and the recommended rating of the machine is 16 A.

How will the chain work then? As long as the current does not exceed 25 A, the machine does not turn off, everything works in the normal mode - the conductor heats up, but not to critical values. When the load current begins to increase and exceeds 25 A, the machine does not turn off for some time - perhaps these are starting currents and they are short-lived. It turns off if the current exceeds 25 A by 13% for a sufficiently long time. In this case, if it reaches 28.25 A. Then the electric bag will work, de-energize the branch, since this current already poses a threat to the conductor and its insulation.

Power calculation

Is it possible to choose an automatic machine according to the load power? If only one device is connected to the power line (usually it is a large household appliance with a large power consumption), then it is permissible to make a calculation based on the power of this equipment. Also in terms of power, you can choose an introductory machine, which is installed at the entrance to a house or apartment.

If we are looking for the value of the introductory machine, it is necessary to add up the power of all devices that will be connected to the home network. Then the found total power is substituted into the formula, the operating current for this load is found.

After you have found the current, select the value. It can be either a little more or a little less than the found value. The main thing is that its tripping current does not exceed the maximum allowable current for this wiring.

When can this method be used? If the wiring is laid with a large margin (this is not bad, by the way). Then, in order to save money, you can install automatic switches corresponding to the load, and not to the cross section of the conductors. But once again we pay attention that the long-term permissible current for the load must be greater than the limiting current of the circuit breaker. Only then will the choice of circuit breaker be correct.

Choosing a breaking capacity

The selection of a packet box for the maximum allowable load current is described above. But the circuit breaker should also turn off when a short circuit (short circuit) occurs from the network. This characteristic is called the breaking capacity. It is displayed in thousands of amperes - this order can be reached by currents during a short circuit. The choice of a machine for breaking capacity is not very difficult.

This characteristic shows at what maximum value of the short-circuit current the machine remains operational, that is, it can not only turn off, but will also work after being turned on again. This characteristic depends on many factors and for accurate selection it is necessary to determine the short-circuit currents. But for wiring in a house or apartment, such calculations are made very rarely, but are guided by the distance from the transformer substation.

If the substation is located near the entrance to your house / apartment, they take an automatic circuit breaker with a breaking capacity of 10,000 A, for all other city apartments, 6,000 A is enough. and a breaking capacity of 4,500 A. The networks here are usually old and short-circuit currents are not large. And since the price increases significantly with increasing breaking capacity, the principle of reasonable economy can be applied.

Is it possible to install bags with a lower breaking capacity in city apartments. In principle, it is possible, but no one guarantees that after the first short circuit you will not have to change it. He may have time to turn off the network, but will be inoperable at the same time. In the worst case, the contacts will melt and the machine will not have time to turn off. Then the wiring will melt and a fire may occur.

Type of electromagnetic release

The machine should operate when the current rises above a certain mark. But the network periodically experiences short-term congestion. They are usually associated with inrush currents. For example, such overloads can be observed when turning on the refrigerator compressor, washing machine motor, etc. The circuit breaker should not trip during such temporary and short-term overloads, because they have a certain delay in operation.

But if the current has increased not because of an overload, but because of a short circuit, then during the time that the circuit breaker “waits”, its contacts will melt. That's why there is an electromagnetic automatic release. It works at a certain current value, which can no longer be an overload. This indicator is also called the cut-off current, since in this case the circuit breaker cuts off the line from the power supply. The magnitude of the tripping current can be different and is displayed by the letters that precede the numbers indicating the rating of the machine.

There are three most common types:

With what characteristic to choose a package? In this case, the choice of a circuit breaker is also based on the remoteness of your household from the substation and the state of the power grid, the choice of a circuit breaker is carried out using simple rules:

• With the letter "B" on the case, they are suitable for summer cottages, houses in villages and towns that receive power through air ducts. They can also be installed in apartments of old houses in which the reconstruction of the house electrical network has not been carried out. These circuit breakers are not always on sale, they cost a little more than category C, but they can be delivered to order.
• Bags with a "C" on the body are the most widely used variant. They are installed in networks with a normal state, suitable for apartments in new buildings or after major repairs, in private houses near the substation.
• Class D is put in enterprises, in workshops with equipment that has high starting currents.

That is, in fact, the choice of a circuit breaker in this case is simple - type C is suitable for most cases. It is available in stores in a large assortment.

Which Manufacturers Should You Trust?

And finally, let's pay attention to manufacturers. The choice of a machine cannot be considered complete if you have not thought about what brand of circuit breakers you will buy. You definitely shouldn’t take unknown firms - an electrician is not an area where you can experiment. Details about choosing a manufacturer in the video.

Electrical overloads are common. To protect appliances powered by electricity from such voltage drops, circuit breakers were invented. Their task is simple - to break the electrical circuit if the voltage exceeds the nominal limits.

The first such devices were plugs familiar to everyone, which are still in some apartments. As soon as the voltage jumps above 220 V, they are knocked out. Modern types of circuit breakers are not only plugs, but also many other varieties. Their remarkable feature is the possibility of repeated use.

Classification

Modern GOST 9098-78 distinguishes 12 classes of circuit breakers:

This classification of circuit breakers is very convenient. If you wish, you can figure out which of the devices to install in the apartment, and which for production.

Types (kinds)

GOST R 50345-2010 divides circuit breakers into the following types (division occurs according to sensitivity to overloads), marked with Latin letters:

These are the main circuit breakers used in residential buildings and apartments. In Europe, the marking begins with the letter A - the most sensitive circuit breakers to overloads. They are not used for domestic needs, but are actively used to protect the power supply circuits of precision instruments.

There are also three more markings - L, Z, K.

Distinctive design features

Automatic devices consist of the following units:

• main contact system;
• arc chute;
• the main drive of the release device;
• various types of release;
• other auxiliary contacts.

The contact system can be multistage (one-, two- and three-stage). It consists of arcing, main and intermediate contacts. Single-stage contact systems are mainly made from sintered metal.

In order to somehow protect parts and contacts from the destructive force of an electric arc, reaching 3,000 ° C, an arc chute is provided. It consists of several arc quenching grids. There are also combined devices that can extinguish a high current electric arc. They contain slit chambers along with a grille.

For any circuit breaker, there is a current limit. Due to the protection of the machine, it can not lead to breakage. With huge overloads of such a current, the contacts can either burn out or even weld to each other. For example, for the most common household appliances with a trip current from 6 A to 50 A, the current limit can be from 1000 A to 10,000 A.

Modular designs

Designed for small currents. Modular automatic switches consist of separate sections (modules). The whole structure is mounted on a DIN rail. Let's consider in more detail the device of the modular switch:

1. On / off is made by a lever.
2. The terminals to which the wires are connected are screw.
3. The device is fixed to the DIN rail with a special latch. This is very convenient, because such a switch can be easily dismantled at any time.
4. The connection of the entire electrical circuit is made due to the movable and fixed contacts.
5. Disconnection occurs with the help of some kind of release (thermal or electromagnetic).
6. Contacts are specially placed next to the arc chute. This is due to the occurrence of a powerful electric arc during the disconnection of the connection.

VA series - industrial switches

Representatives of these machines are primarily intended for use in AC circuits of 50-60 Hz, with an operating voltage of up to 690 V. They are also used for direct current of 450 V and current strength of up to 630 A. Such switches are designed for very rare operational use ( no more than 3 times per hour) and protection of lines from short circuit and electrical overload.

Important features of this series include:

• high breaking capacity;
• a wide range of electromagnetic releases;
• button for testing the device with free tripping;
• load break switches with special protection;
• remote control through a closed door.

AP series

Automatic circuit breaker ap is able to protect electrical installations, motors from sudden voltage surges and short circuits within the network. The launches of such mechanisms are not intended to be very frequent (5-6 times per hour). Automatic switch ap can be two-pole and three-pole.

All structural elements are located on a plastic base, which is closed with a lid on top. In case of large overloads, the free tripping mechanism is activated, and the contacts open automatically. At the same time, the thermal release withstands the operating time, and the electromagnetic release provides instantaneous disconnection in the event of a short circuit.

When operating the machine, it is desirable to adhere to the following conditions:

1. With air humidity of 90%, the temperature should not exceed 20 degrees.
2. The operating temperature ranges from -40 to +40 degrees.
3. Vibration at the attachment point should not exceed 25 Hz.

It is strictly forbidden to work in an explosive atmosphere containing gases that destroy metal and winding, near the pure energy of heating devices, water flows and splashes, in places with conductive dust.

The variety of circuit breakers allows you to easily choose a device for an apartment or house. It is best to invite a specialist to install it.

Installation of protective equipment is an important stage in the construction of electrical networks. In the event of the occurrence of large currents, heating occurs, causing the melting of the insulating layer of the conductor. This situation leads to a fire. A sharp increase in the magnitude of the current is associated with a short circuit that occurs during the operation of faulty equipment.

In order to avoid the threat of fire and damage to wires, various types of electric machines are used, depending on the parameters used in conjunction with electrical devices.

Principle of operation and varieties

The principle of operation of electrical switches is to break the electrical circuit when a short circuit occurs. Or exceeding the permissible power for which the electrical network is designed. Electric circuit breakers are always located at the beginning of the protected section of the circuit. In this case, the type of connected load does not matter.

According to their form and parametric values, automata are divided into:

• by the number of poles;
• according to the time-current characteristic;
• by rated current.

It is also necessary to note the current limiting class. This value is characterized by the speed of the device's response to an emergency situation. The division is into three classes. For domestic use, the third class is used.

Regardless of their characteristics, the principle of operation for all switches is identical. To connect the machine to the electrical network, it is necessary to set the control switch to the "on" position. The current flowing to the switch is fed through the input terminal to the solenoid coil, and from it to the bimetallic plate. The plate is a strip of two pressed metals with different coefficients of thermal linear expansion. The current from the plate comes to the output terminal and then enters the electrical circuit. The plate and solenoid are called releases.

Current release- an important design element, it can be:

• electromagnetic (solenoid);
• thermal (bimetallic plate);
• combined (combination of thermal and electromagnetic);
• independent (remotely acting on the switch, it turns off).

There are two conditions under which the electrical switch will trip to open the line: overload mode and short circuit mode.

The principle of operation in overload mode is based on the ability of a bimetallic strip to bend under the influence of heat. With an increase in power to the line, the current flowing through the electric machine increases, exceeding the working value switch. As a result, the release heats up, its plate bends, and the contact breaks. Accordingly, the electrical circuit is broken. The current supply is stopped. The amount of current at which the plate breaks the contact is set at the factory with an adjustment screw. After the plate has cooled, it returns to its previous shape, and the contact appears again.

In the short circuit mode, the current increases very quickly, the magnetic field formed by it in the solenoid sets the core in motion. The core acts on the release, and the electrical circuit breaks, and an arc appears. The appearance of an arc negatively affects the internal parts of the machine, therefore, a device for extinguishing it is used. The arc chute is made of plates parallel to each other, passing through which the arc dissipates.

Thus, the main structural parts can be noted:

• current terminals;
• release:
• control lever;
• release adjusting screw;
• arc chamber.

Number of poles

The number of poles indicates how many wires can be passed through the switch at the same time. There are devices with the number of outputs from one to four. The device of a single-pole switch is no different from a multi-pole one, only in the second case, when the passage of electric current several chains are broken at the same time.

Single-pole devices are more often used in domestic conditions and are placed in a break in the phase wire, the zero one is connected directly through the block, as an introductory machine, its use is not recommended. For installation at the entrance, two-pole circuit breakers are used, the phase and neutral wires are connected to them at the same time. For use in a three-phase network, a three-pole machine is already used as an input. To protect a four-phase electrical network, for example, a star-connected motor, a four-phase automatic machine is used. In this case, three phase and one neutral wire are connected.

The usual scheme for building protection on electrical switches comes down to installing an input automaton of the required number of poles. After it, single-pole ones are installed - one for each group. In this case, the value of the rated current of a single-pole machine is already calculated based on the parameters of the group to which it is connected. Its value is chosen less than the input value.

Time-current characteristic

This parameter indicates the ratio of the actual current flowing through the machine to the nominal value. Depending on the value of the ratio, the sensitivity of the automaton is determined, which is characterized by the number of false positives. There are different types of machines. They are marked with letters of the Latin alphabet. The most common switches are labeled B, C and D.

Electric machines with characteristic B are switched off within 5-20 seconds. In this case, the current value can exceed the nominal value by five times. These models are widely used in domestic premises. Marking C means switching off interval 1-10 seconds, while the load is ten times the value. Class D circuit breakers are used to protect engines. The operating current exceeds the nominal by 14−20 times.

Rated current

Indicates the amount of current that can pass through an electric machine without it tripping. Strictly defined values ​​\u200b\u200bare produced from 1 to 63 amperes. There are 12 values ​​in total: 1A, 2A, 3A, 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A.

The choice of rated current depends on the power value that the wiring can withstand without damage. This value is determined by the cross section of the wire and the material of its manufacture. In homes, the most popular machines for use are 6A, 10A and 16A. Automatic machines with a nominal value of 20A, 25A, 32A are used in apartments as introductory, i.e., two-pole.

Location and accommodation

The method of placement (whether it is a single-phase electric machine or another type) is strictly vertical. The fixed part of the control lever must be on top, i.e. the device is switched on by switching from bottom to top. Devices are placed in accessible places, and the possibility of their mechanical damage is excluded.

DIN rail mounting is the most popular. Usually such a rail is installed in the shield. Electrical switches structurally have special grooves into which the rail is inserted.

What are the machines, how are they marked - you need to know this information in order to choose the right device. Regardless of the manufacturer and type of electric machines, they are always marked on the front side. Marking is carried out according to a single scheme. It includes an indication of all the main parameters:

On the control lever, inscriptions are made indicating the set position - “on.” and "off" or "1" and "0".

Leading brands and manufacturers

The leaders in the production of circuit breakers are the following brands:

These are well-known brands that produce any kind of electric machines. They are characterized by high quality housing, long service life and high mechanical strength. Often, protective covers are additionally installed on them. These manufacturers produce their devices from solid materials. Their quality is confirmed by certificates and a warranty period given by manufacturers for their products.