The magnetic starter has power contacts designed for switching circuits under load and block contacts which are used in control circuits.

Contacts are divided into normally open- contacts that are in their normal position, i.e. before applying voltage to the coil of the magnetic starter or before mechanical impact on them, are in an open state and normally closed- which in their normal position are in a closed state.

The new magnetic starters have three power contacts and one normally open block contact. If it is necessary to have a larger number of block contacts (for example, during assembly), an attachment with additional block contacts (contact block) is additionally installed on the magnetic starter on top, which, as a rule, has four additional block contacts (for example, two normally closed and two normally open).

Each button of the push-button post has two contacts - one of them is normally open, and the second is normally closed, i.e. Each of the buttons can be used both as a “Start” button and as a “Stop” button.

1. Electric motor direct connection diagram

This diagram is the simplest diagram for connecting an electric motor; it does not have a control circuit, and the electric motor is turned on and off by an automatic switch.

The main advantages of this scheme are its low cost and ease of assembly, but the disadvantages of this scheme include the fact that circuit breakers are not intended for frequent switching of circuits; this, in combination with inrush currents, leads to a significant reduction in the service life of the machine; in addition, this scheme does not include Possibility of additional motor protection.

1. Connection diagram for an electric motor via a magnetic starter

This scheme is also often called simple motor starting circuit, in it, unlike the previous one, in addition to the power circuit, a control circuit also appears.

When you press the SB-2 button (the “START” button), voltage is applied to the coil of the magnetic starter KM-1, while the starter closes its power contacts KM-1 starting the electric motor, and also closes its block contact KM-1.1 when the button is released SB-2 its contact opens again, but the coil of the magnetic starter is not de-energized, because its power will now be provided through the KM-1.1 block contact (i.e. the KM-1.1 block contact bypasses the SB-2 button). Pressing the SB-1 button (the “STOP” button) leads to a break in the control circuit, de-energizing the magnetic starter coil, which leads to the opening of the magnetic starter contacts and, as a result, to stopping the electric motor.

1. Reversible motor connection diagram (How to change the direction of rotation of an electric motor?)

To change the direction of rotation of a three-phase electric motor, you need to swap any two phases supplying it:

If it is necessary to frequently change the direction of rotation of the electric motor, the following is used:

This circuit uses two magnetic starters (KM-1, KM-2) and a three-button post; the magnetic switches used in this circuit, in addition to a normally open block contact, must also have a normally closed contact.

When you press the SB-2 button (START 1 button), voltage is applied to the coil of the magnetic starter KM-1, while the starter closes its power contacts KM-1 starting the electric motor, and also closes its block contact KM-1.1 which bypasses the button SB-2 and opens its block contact KM-1.2 which protects the electric motor from turning on in the opposite direction (when the SB-3 button is pressed) until it stops first, because An attempt to start the electric motor in the opposite direction without first disconnecting the KM-1 starter will result in a short circuit. To start the electric motor in the opposite direction, you need to press the “STOP” button (SB-1), and then the “START 2” button (SB-3), which will power the coil of the KM-2 magnetic starter and start the electric motor in the opposite direction.

A contactor is an electromagnetic device designed for switching, that is, turning on and off electrical equipment. It is a two-position mechanism that is used for frequent switching. The main elements of its design are:

1. Power contact group, which can be two or three-pole depending on the voltage required for the operation of the actuator.
2. Arc suppression chambers, which are aimed at reducing the arc that occurs when an electric current breaks;
3. Electromagnetic drive. It is designed to move the moving part of the power contact. Depending on the design, it can be designed for different voltages, both direct and alternating current. Made from a U-shaped or W-shaped core;
4. A system of block contacts required for signaling and controlling the operational circuits of the contactor. Using them, you can connect a sound or light alarm indicating the position of the contactor, as well as for the self-retaining circuit.

A distinctive feature of the design of an electromagnet operating with alternating current is the presence of a short-circuited coil, which prevents its iron from humming during operation. If the electromagnet operates on direct current, then between its disconnected parts there must be a non-metallic gasket that prevents the core from sticking. A contactor differs from a magnetic starter or relay, only in working with a more powerful load; the dimensions of the device itself depend on its size. It is very important to choose the right contactor corresponding to the current that it will switch.

Modern devices of the KMI series have good reliability indicators and are intended for general industrial use. Due to their design, they have an easy method of fastening and small dimensions.

Principle of operation

When voltage is applied to the electromagnet coil, the moving part of the device is set in motion under the influence of electromagnetic forces and is attracted to the stationary part. In this case, the power contacts are closed and voltage is supplied to the actuator. And also at the same time there is movement of block contacts, which can be making or breaking.

How to connect a contactor

When connecting a contactor, you immediately need to decide on the mechanism that it will turn on. This could be a motor, pump, fan, heating elements, compressors, etc. The main feature of a contactor that distinguishes it from a machine is the absence of any protection. Therefore, when thinking through the circuits for switching on electrical equipment through a contactor, it is necessary to take into account the current-limiting and heating elements. To limit and shut down equipment in case of short circuits and loads many times higher than the rated load, fuses and circuit breakers are used. Thermal relays are used to prevent long-term slightly exceeding the rated currents of operating equipment.

In order to correctly connect a contactor to a circuit, you need to clearly understand which of the contacts are power and which of them are auxiliary, that is, block contacts. You also need to look at the ratings of the switching coil. The voltage, its type and magnitude, as well as the currents that flow through it for normal operation must be indicated there. During operation, power contacts may burn, so they must be inspected and cleaned regularly.

How to connect a modular contactor

A modular contactor is a type of conventional switching devices of the same type, only they are mainly used for switching switchboards on and off remotely. That is, turning it on, power is supplied to a group of machines, each of which is responsible for its own specific circuit. It is installed on a DIN rail. Can switch both direct and alternating current circuits.

Connecting a contactor via a button

To connect the contactor via a button, you need to study the attached diagram below. It is designed to start a load, in this case a motor, from a contactor whose coil is designed for 220 Volts alternating voltage. Depending on the voltage, it is worth considering its power supply. Therefore, when purchasing and selecting a contactor, it is worth taking this nuance into account. Since if the electromagnet is designed for constant voltage, then such a source will be needed.

When you press the start button, the contactor electromagnet coil will receive power and it will turn on. The power contacts will close, thereby supplying voltage to the asynchronous motor. The block contact of contactor K1, which is connected in parallel to the stop button, will also close. It is called by electricians a self-retaining contact, since it is this that supplies power to the switching coil after the start button is released. When you press the stop button, the power from the electromagnet is turned off, the power elements of the contactor break the circuit and the engine turns off.

Connecting a contactor with a thermal relay

The thermal relay is designed to prevent prolonged minor current overloads during operation of electrical equipment, because overheating negatively affects the condition of the insulation. Frequent excesses of temperature and current will lead to its destruction, and therefore to a short circuit and failure of an expensive actuator.

When the current in the stator circuit of the electric motor increases, the elements of the thermal relay KK will heat up. When the set temperature, which can be adjusted, is reached, the thermal relay will operate and its contacts will break the circuit of the electromagnet coil of the KM contactor.

For safety reasons, you must remember that work in the contactor circuit must be carried out when it is completely de-energized. In this case, the power supply must be locked with a key or prohibiting sign from unauthorized or erroneous activation. And also you cannot turn on this device with the arc chutes removed, this will lead to a short circuit.

Video about connecting a contactor

First of all, you need to understand what a switching device is and why it is needed. Then coping with the task of creating a circuit based on MP for lighting, heating, connecting pumps, compressors or other electrical equipment will become much easier.

Contactors or so-called magnetic starters (MP) are electrical equipment designed to control and distribute energy supplied to an electric motor. The presence of this device provides the following advantages:

• Protects against inrush currents.
• A well-designed circuit provides protection elements in the form of electrical interlocks, self-retaining circuits, thermal relays, etc.
• Control elements (buttons) are installed to allow the engine to start in reverse mode.

The contactor connection diagrams are quite simple, allowing you to assemble the equipment yourself.

Before connecting, you need to familiarize yourself with the operating principle of the device and its features. The MP contactor turns on the control pulse that comes from the start button after it is pressed. This is how voltage is supplied to the coil. According to the self-retaining principle, the contactor is held in connection mode. The essence of this process is to connect an additional contact in parallel to the start button, which supplies current to the coil, so there is no need to hold the start button pressed.

With the equipment of a shutdown button in the circuit, it becomes possible to break the control coil circuit, which turns off the MP. The control buttons of the device are called a push-button station. They have 2 pairs of contacts. The universalization of control elements is made to organize possible circuits with instant reverse.

The buttons are labeled with a name and color. Typically, the enabling elements are called "Start", "Forward" or "Start". Indicated by green, white or other neutral color. The opening element is called "Stop", a button of an aggressive, warning color, usually red.

The circuit must be switched with a neutral when using a 220 V coil in it. For options with an electromagnetic coil with an operating voltage of 380 V, the current taken from the other terminal is supplied to the control circuit. Supports operation in AC or DC voltage networks. The principle of the circuit is based on the electromagnetic induction of the coil used with auxiliary and working contacts.

There are two types of MP with contacts:

1. Normally closed - power supply to the load is turned off at the moment the starter operates.
2. Normally open - power is supplied only during MP operation.

The second type is used more widely, since most devices operate for a limited period, being mostly at rest.

Composition and purpose of parts

The design of a magnetic contactor is based on a magnetic circuit and an inductance coil. The magnetic core consists of metal elements divided into 2 parts in the shape of “W”, located mirror to each other inside the coil. Their middle part plays the role of a core, enhancing the induction current.

The magnetic core is equipped with a movable upper part with fixed contacts to which the load is supplied. Fixed contacts are fixed to the MP body, on which the supply voltage is established. A rigid spring is installed inside the coil on the central core, which prevents the contacts from connecting when the device is off. In this position, no power is supplied to the load.

Depending on the design, there are MFs of small ratings for 110 V, 24 V or 12 V, but they are more widely used with voltages of 380 V and 220 V. Based on the value of the supplied current, 8 categories of starters are distinguished: “0” - 6.3 A; “1” - 10 A; “2” - 25 A; “3” - 40 A; “4” - 63 A; “5” - 100 A; “6” - 160 A; "7" - 250 A.

Principle of operation

In the normal (off) state, the contacts of the magnetic circuit are opened by a spring installed inside, which lifts the upper part of the device. When connected to the MP network, an electric current appears in the circuit, which, passing through the turns of the coil, generates a magnetic field. As a result of the attraction of the metal parts of the cores, the spring is compressed, allowing the contacts of the movable part to close. After this, the current gets access to the motor, starting it to work.

IMPORTANT: For alternating or direct current supplied to the MP, it is necessary to maintain the rated values ​​specified by the manufacturer! As a rule, for direct current the voltage limit is 440 V, and for alternating current it should not exceed 600 V.

If the “Stop” button is pressed or the power to the MP is turned off in some other way, the coil stops generating a magnetic field. As a result, the spring easily pushes out the upper part of the magnetic circuit, opening the contacts, which leads to the cessation of power supply to the load.

Connection diagram for a starter with a 220 V coil

To connect the MP, two separate circuits are used - signal and working. The operation of the device is controlled via a signal circuit. The easiest way is to consider them separately to make it easier to understand the principle of organizing the circuit.

Power is supplied to the device through contacts located on the top of the MP housing. They are designated in diagrams A1 and A2 (in the standard version). If the device is designed to operate in a network with a voltage of 220 V, then this voltage will be supplied to the indicated contacts. There is no fundamental difference between connecting “phase” and “zero”, but usually “phase” is connected to pin A2, since this pin is duplicated in the lower part of the housing, which facilitates the connection process.

To supply the load from the power source, contacts located on the bottom side of the case and marked as L1, L2 and L3 are used. The type of current does not matter, it can be constant or alternating, the main thing is to comply with the nominal limit, limited to a voltage of 220 V. The voltage can be removed from the outputs designated T1, T2 and T3, which can be used to power a wind generator, battery and other devices.

The simplest scheme

When connecting a power cord to the contacts of the moving part of the MP, followed by supplying voltage of 12 V from the battery to outputs L1 and L3, and powering lighting devices to the outputs of the power circuit T1 and T3, then a simple circuit is organized to illuminate a room or space from Battery This scheme is one of the possible examples of using MP for domestic needs.

To power an electric motor, magnetic starters are used much more often. To organize this process, supply voltage from a 220 V network to outputs L1 and L3. The load is removed from contacts T1 and T3 of the same voltage rating.

These circuits are not equipped with a trigger mechanism, i.e. not used when organizing buttons. To stop the operation of the connected equipment via the MP, it is necessary to disconnect the plug from the network. When organizing a circuit breaker in front of the magnetic starter, you can control the time of current supply without the need for complete disconnection from the network. The circuit can be improved with a pair of buttons: “Stop” and “Start”.

Diagram with “Start” and “Stop” buttons

Adding control buttons to the circuit changes only the signal circuit, without affecting the power circuit. The overall design of the circuit will undergo minor changes after such manipulations. Control elements can be located in different housings or in one. The single-block system is called a “push-button post”. Each button has a pair of outputs and inputs. The contacts on the “Stop” button are normally closed, and on the “Start” button they are normally open. This allows you to organize power supply as a result of pressing the second one and break the circuit when the second one is initiated.

In front of the MP, these buttons are built in sequentially. First of all, it is necessary to set “Start”, which ensures that the circuit operates only as a result of pressing the first control button until it is held. When the switch is released, the power supply is interrupted, which may not require the organization of an additional interrupt button.

The essence of arranging a push-button post is the need to organize only pressing “Start” without the need for subsequent holding. To organize this, a coil is introduced that bypasses the start button, which is placed on self-feeding, organizing a self-retaining circuit. This algorithm is implemented by closing auxiliary contacts in the MP. To connect them, a separate button is used, and the moment of turning them on must be simultaneously with the “Start” button.

After pressing “Start” it is passed through the auxiliary power contacts, closing the signal circuit. There is no need to hold the start button, but to stop, you need to press the corresponding “Stop” switch, which initiates the return of the circuit to its normal state.

Connection to a three-phase network via a contactor with a 220 V coil

Three-phase power can be connected through a standard MP, which operates from a network with a voltage of 220 V. This circuit can be used for switching when working with asynchronous motors. The control circuit does not change; “zero” or one of the phases is supplied to the input contacts A1 and A2. A phase wire is passed through the “Stop” and “Start” buttons, and a jumper is equipped for the output normally open contacts.

Certain minor adjustments will be made for the power circuit. For three phases, the corresponding inputs L1, L2, L3 are used, where the three-phase load is output from the outputs T1, T2, T3. To prevent overheating of the connected motor, a thermal relay is built into the network, which operates at a certain temperature, opening the circuit. This element is installed in front of the engine.

Temperature control is carried out in two phases, which have the highest load. If the temperature in any of these phases reaches a critical value, an automatic shutdown occurs. It is often used in practice, noting its high reliability.

Reverse motor connection diagram

Some devices work with motors that can rotate in both directions. If you transfer the phases on the corresponding contacts, you can easily achieve this effect from any motor device. This can be organized by adding to the button post, in addition to the “Start” and “Stop” buttons, another one - “Back”.

The MP circuit for reverse is organized on a pair of identical devices. It is better to choose a pair equipped with normally closed contacts. These parts are connected in parallel to each other; when the reverse motion of the motor is organized, as a result of switching on one of the motors, the phases will change places. The load is applied to the outputs of both devices.

The organization of signal circuits is more complex. Both devices use a common “Stop” button followed by a “Start” control. The latter is connected to the output of one of the MPs, and the first - to the output of the second. For each control element, shunt circuits are organized for self-retaining, which ensures autonomous operation of the device after pressing “Start” without the need for subsequent holding. The organization of this principle is achieved through the installation of jumpers on normally open contacts on each MP.

An electrical interlock is installed to prevent power from being supplied to both control buttons at once. This is achieved by supplying power after the “Start” or “Forward” button to the contacts of another MP. The connection of the second contactor is similar, using its normally closed contacts in the first starter.

If there are no normally closed contacts in the MP, by installing the attachment you can add them to the device. With this installation, the work of the set-top box contacts is performed simultaneously with others due to the connection with the main unit. In other words, it is impossible to open the normally closed contact after turning on the Start or Forward button, which prevents reverse movement. To change direction, press the “Stop” button, and only after that the other one, “Back,” is activated. Any switching must be done via the "Stop" button.

Conclusion

A magnetic starter is a very useful device for any electrician. First of all, it makes it easy to work with an asynchronous motor. When using a 24 V or 12 V coil, powered by a conventional battery, subject to appropriate safety measures, it is even possible to start equipment designed for high currents, for example, with a load of 380 V.

To work with a magnetic starter, when drawing up a circuit, it is important to take into account the features of the device and carefully monitor the characteristics indicated by the manufacturer. It is strictly forbidden to supply a current of a higher voltage or strength to the outputs than indicated in the marking.

A magnetic starter is an electrical device that is designed to start at a distance, assist in operation, turn off and save an electric motor. It is easy to assemble a diagram for connecting a magnetic starter via a push-button post. The operation of an MF is based on the effect of the appearance of a magnetic field when current penetrates through an induction load, that is, through a coil.

What is MP used for?

Starters are often used to mechanically turn on heaters, lighting lines, etc. They are also used to operate engines. MP connection diagrams differ mainly depending on which coil is located in it. It is not difficult to turn on the starter yourself, but you can make it easier and purchase the starter already assembled, preferably with a plastic case.

In it, the structure is already assembled and the control buttons on the lid are connected. You only need to connect the electrical cables at the top and the outlet wire to the load.

MP coil

The coil is the main part of the MP; it creates an electromagnetic field when electricity passes through it, and involves an armature, 3 or 5 pairs of mobile contacts. The type of coil depends on the voltage in the installation. They can operate from 220 volts or are designed for 380 volts. The coil, with a calculated 220 volts, is connected to the terminals between ground and phase. 380 volts are connected between phases.

The voltage value is usually written on its terminal next to the bolt with which the wire is clamped. If you turn on a 220-volt coil like a 380-volt coil, it will explode.

Preparing for assembly

Before directly assembling the circuit for connection, you need:

Types of starter designs

For the reversible design of the MP, the first, third and fifth terminals are connected with the same numbers of the adjacent device. And the outgoing wires are connected crosswise: the second to the sixth, the fourth to the fourth, the sixth to the second. The wire that powers the electric motor is connected to the second, fourth and sixth terminals of any starter.

The cross connection circuit prohibits the simultaneous operation of two devices, as this will lead to a short circuit.

Because of this, it is necessary that the conductor of the circuit block of both starters pass first through the closed contactor of the other, and then through the open contact of its own. Then when you turn on the first device, the second device will turn off and vice versa.

Some MP designs require only 5 pairs of contactors that close. Then the wire of the circuit block of the 1st MP is connected to the closed “Start” contacts of the other. This design operates in a start-stop manner.

3 wires are connected to the second terminal of the “Stop” button: 2 blocks and one that powers the “Start” button; these wires are connected in parallel to each other. With this design, “Stop” turns off any device and stops the operation of the electric motor.

All work on installation and repair of MP structures is done after the voltage has been removed, even if the control switches the neutral.

MP connection diagram

A popular scheme for connecting a magnetic starter via a push-button post.

The main circuit has two parts:

1. Three pairs of power contacts direct electrical power to electrical equipment.
2. A graphical representation of the control, which consists of a coil, buttons and additional contactors that take part in the operation of the coil or prevent erroneous activation.

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The most common wiring diagram is with one device. It's the easiest thing to deal with. To connect its main parts, you need to take a three-core cable and a pair of open contactors when the device is turned off.

Scheme with connecting a 220 volt coil

Will analyze a design with a voltage of 220 volts. If the voltage is 380 volts, you need to connect a different type of phase instead of the blue zero. In this situation, black or red. In case of blocking of the contactor, the fourth pair is taken, which works with 3 power pairs. They are located at the top, but the side ones are located on the side.

Pairs of power contactors are supplied with 3 phases A, B and C from the machine. To turn on when you touch the “Start” button, it is necessary that the voltage be equal to 220 V on the core, which will help the movable contactors connect with those that are stationary. The circuit will begin to close; to disconnect it, you need to disconnect the coil.

To assemble the control circuit, you need to connect one phase directly to the core, and connect the second phase using a wire to the start contact.

From the 2nd contactor we lay 1 more wire through the contacts to the other open contact of the “Start” button. A blue jumper is also made from it for the closed contactor of the “Stop” button; a zero from the electrical supply is connected to the 2nd contactor.

Working principle

The operating principle is simple. If you press the “Start” button, its contacts begin to close and a voltage of 220 volts flows to the core - it triggers the main and side contacts and an electromagnetic flux occurs. If the button is released, the contactors of the start button open, but the device is still turned on, since zero is transmitted to the coil through the closed blocking contacts.

In order to turn off the MP, you need to break the zero by opening the contacts of the “Stop” button. Again the device will not turn on, because the zero will be broken. To turn it on again, you will need to click “Start”.

How to connect a thermal relay?

You can also make a single-line graphic drawing of the connection of a three-phase electric motor to a magnetic starter via a relay.

Between the MP and an asynchronous electric motor, a relay is connected in series, which is selected depending on the specific type of motor. This device protects the motor from breakdowns and emergency conditions (for example, when one of the three phases disappears).

The relay is connected to the output from the MP to the electric motor, electricity passes through it in a series manner through the heating of the relay to the electric motor. On top of the relay there are additional contactors, which are combined with the coil.

Relay operation

Thermal relay heaters are designed for the maximum current that passes through them. When the current rises to unsafe limits for the motor, the heaters turn off the MP.

Installation of starters inside an electrical panel

The design of the MP allows installation in the middle of the electrical panel. But there are rules that apply to all devices. To ensure high reliability of operation, it is necessary that the installation be made on an almost straight and solid plane. Moreover, it is located vertically on the wall of the electrical panel. If there is a thermal relay in the design, then it is necessary that the temperature difference between the MP and the electric motor be as small as possible.

In what places should you not install MP?

To prevent accidental activation of the starter or to protect it, do not install the device in places that are susceptible to shocks, shocks, or shaking.

It is also impossible to install the MP in the same room with devices that have a current higher than 150 A. When these devices are turned on and off, a quick shock occurs.

The wires in the wiring diagram also need to be routed correctly. In order for there to be good contact and no bending of the spring clamp washers, it is necessary to bend them in a round shape.

The design of the device is made after removing the voltage. The cores can operate from 220 volts or 380 volts. You can also buy a ready-made MP, this will greatly simplify the situation.

For those who had a normal attitude towards studying a school physics course, it will not be difficult to understand the connection diagrams of various electrical equipment, including three-phase electric motors. They are connected via contactors or magnetic starters. Foreign classification does not make any difference between these devices, since the starter is the same contactor, but equipped with additional devices for the safe operation of the current consumer.

In other words, a starter is a kind of miniature electrical cabinet, in which, in addition to the contactor, thermal protection and short circuit protection are installed. The starters have 8 values ​​from “0” to “7”, each of which is designed for electric motors with a certain power range (rated current). Thanks to the closed design (in the housing), the starters can be installed anywhere. When connecting electric motors via a contactor, protective devices are selected separately.

Contact system on the contactor

Regardless of the standard size and manufacturer of electrical equipment, any three-phase contactor has a standard diagram of contacts and their connections. For ease of installation, all contacts are marked indicating their purpose. The marking is applied to the body of the device and looks like this:

• A1 (zero) and A2 (phase) – contacts for controlling the switching on and off of the contactor;
• Odd numbers 1, 3, 5 and markings L1, L2, L3 indicate the three-phase power input locations;
• Even numbers 2, 4, 6 and markings T1, T2, T3 indicate the connection points of the wires going to the current consumer;
• 13NO and 14NO are a pair of block contacts to provide the self-latching function.

Contact A2 is duplicated in the upper and lower parts of the device body for ease of switching. For the same purpose, the upper and lower (odd and even) group of power contacts can also be used to input or output power. When installing the contactor, you must be careful, otherwise the circuit will not work.

Incorrect phase connections must not be allowed. If you mix them up when installing the contactor, you will get reverse rotation of the motor. For this purpose, there are two ways of marking the insulation of cable cores - with numbers and color. The colors 1, 2 and 3 are yellow, green and red. The neutral conductor is white or marked with the number “0”. Connecting power contacts is not difficult. The main thing is the correct connection of the control voltage through the push-button station.

Connecting a push-button post

Let's consider 2 diagrams for connecting a contactor to a 380 V network: for a coil with a supply voltage of 380 V and 220 V.

The push-button post has two buttons. “Start” with normally open and “Stop” with normally closed contacts. Power is supplied to it (phase) through contact No. 4 of the “Stop” button. We install a jumper between terminals No. 3 “Stop” and No. 2 “Start,” thereby extending the “phase” line. Terminal A1 (phase) of the contactor is connected to contact No. 1 “Start”. The neutral conductor of the control wire is connected to terminal A2. A jumper is installed between the double contact A1 and terminal 14NO. Terminal 13NO is connected to contact No. 2 “Start”.

If the control circuit needs to be powered from one phase (phase-zero), with a starter coil rating of 220 V, the connection diagram will look like this.

When you press the “Start” button, the power contacts are activated and voltage is supplied to the block contact, which ensures the working (closed) position of the power contacts after the button is released. By pressing the “Stop” button, the circuit on the block contact is broken, and the power contacts move to the normally open position. More detailed descriptions of connecting contactors with illustrations and videos can be found on the Internet. Having done this work several times, in the future you will perform it automatically.