How to connect a two-key, one-key and pass-through light switch. Step-by-step instructions on how to properly connect a switch to a lamp Connecting a light switch

Tsugunov Anton Valerievich

Reading time: 4 minutes

When installing or repairing a home, the need to install or replace light switches inevitably arises. Such work is not particularly difficult and can easily be carried out by a non-specialist who has an understanding of what a lamp connection diagram is and what electrical safety rules should be followed when installing it. That is why, before starting such work, you should first figure out how to connect the light switch.

The use of single-key devices is advisable in cases where it is necessary to organize the switching of the wire through which one light bulb or lamp receives power. If you need to connect a chandelier that contains a large number of lamps, then it is better to use a multi-key device. Another case in which it is preferable to use two- or three-key switches is the situation when, using such a device, it is necessary to turn on light bulbs in different rooms, for example, in the corridor, bathroom and toilet.

Required tools and materials

Before you begin installing a single-key switch, you need to ensure that you have the following tools and consumables:

1. Switch.
2. Lamp with lamp.
3. Insulating tape.
4. Knife for stripping insulation.
5. Indicator screwdriver.

If before installing the switching device the wiring has not been done and the socket box has not been installed, you will have to stock up on the following additional tools and materials:

1. Alabaster.
2. Junction box. This part is needed only when it is necessary to install new wiring in the room. Otherwise, you just need to find the nearest installed box and connect the light and switch through it.
3. Hammer.
4. Container for mixing putty.
5. Grinder with a circle on concrete.
6. Ladder.
7. Putty knife.
8. Wires.

Based on the installation method, there are two types of such devices: internal and overhead. Their principle of operation is no different and lies in the fact that when you press a key, an electrical circuit is closed or opened.

The overhead type product is used mainly in rooms with wooden walls. Its main advantage is its extreme ease of installation. Such a device can easily be used as a temporary switch, which is installed in order to avoid large-scale repair work that is fraught with large financial costs.

The built-in model certainly looks more compact and aesthetically pleasing than its previous counterpart. However, to install it, it is necessary to provide hidden wiring. Such work requires the need to gouge walls to lay electrical wires, which can lead to a large amount of dust and damage to the wall cladding. That is why they try to combine the installation of built-in sockets and switches with renovation work in the apartment.

• Plastic key. Serves to conveniently turn on and off device contacts.
• Decorative frame. This element is made of dielectric material and also serves as protection against electric shock. The frame can be attached to the main part using plastic latches or metal bolts.

Somewhat more complex is the design of a backlit switch, which has an undeniable advantage - it is clearly visible in the dark. This function not only saves a person from having to fumble in the dark looking for a switch, but also makes it possible to use this device as a kind of night light.

There are also modular and waterproof switches. Modular devices are designed for installation in a cable channel and are mainly used for connecting lamps in office premises. As for moisture-proof models, their use is advisable in rooms with high air humidity, for example, in bathrooms, bathrooms or outdoors when connecting external lamps.

Single-key switch connection diagram

The main rule that must be observed when installing switching devices is the need to install them on a phase wire. In other words, when a light bulb, lamp or other consumer is turned off using such a device, a phase is lost at its input. This provides a guarantee of protection against accidental electric shock in the event of damage to the insulation of electrical wiring or when touching exposed live parts.

If the switch is connected correctly, then when it is turned off, you can change burnt out light bulbs and perform maintenance work on the lamp without any risk.

The light switch is installed according to the diagram shown in the figure.

As can be seen from the diagram, correctly connecting the light switch does not cause any difficulties. The picture also shows the ground wire running through the junction box to the light fixture. In the electrical wiring of older houses, such a conductor may not be present.

As can be seen from the diagram, it provides two different paths for current to flow through two switches installed in the circuit. The luminaires are powered only if the switch contacts close the conductors of the same branch. This can be done by changing the position of the key of any of them.

Installation procedure

Before installing the switch, it is necessary to lay the electrical wires connecting the lamp, the junction box and the switch itself.

If a built-in type device is being mounted, then you must first install the socket box, releasing approximately 10 cm of wire from it. This should be done for the convenience of connecting the wire to the switch contacts.

Installation of the socket box (box) is carried out in the same way as in the case of connecting an electrical outlet. After drilling a recess in the wall, the socket box is fixed in it using alabaster.

If all the preparatory work has already been done, then you can begin installing the switch.

Step-by-step instructions for correctly installing a single-key switch are as follows:

1. Disconnect the electrical network. This can be done using a machine or plugs located on the input panel.
2. Remove the key. It is attached to the elements of the working part using plastic grooves. Therefore, this element can be removed with your fingers without much effort.
3. Remove the protective frame, which in most cases is attached to the operating mechanism with two screws.
4. Remove insulation from the ends of the wire intended for connection to the switch terminals. If the working part of the device provides for connecting wires using a bolted connection, then you need to remove approximately 1 cm of insulation from each wire. If self-clamping contacts are used, 0.5 cm will be sufficient.
5. Connect the ends of the wire to the contacts of the switch. In this case, you should pay attention to their correct connection in accordance with the contact markings. Many models of these devices use the designation L or 1 for the incoming wire and a 3 or arrow for the outgoing wire. When tightening the bolts, the force must be calculated so as not to damage the contacts. This is especially true for cheap switch models. You should also pay attention to the fact that there should be no wire insulation under the bolts, as this can lead to overheating and even destruction of the connection points.
6. Install the working mechanism into the socket box. For this purpose, sliding legs or special screws are used. When installing such a device, it is important not to confuse its upper and lower parts. A properly installed switch will be in the on position when the top of the key is pressed. To determine in which state of the working mechanism the circuit closes, it is enough to make several test switches on and off. To turn on the mechanism, you need to apply some force, and when turning it off, just lightly touch the key - a special spring helps to break the electrical connection faster.
7. Install the protective frame. To achieve the correct positioning of the frame, you can use a building level.
8. Set a key.

HELPFUL INFORMATION: Installation of two-key switches, connection diagram

When installing a backlit switch, all work is performed in the same way as when connecting an ordinary device. The only difference is the need to connect a small electrical circuit consisting of a current-limiting resistor and a neon light bulb or LED to the switch contacts.

The principle of operation of such illumination is quite simple. Due to the high resistance of the resistor, when the switch contacts are closed, practically no electric current passes through the LED. But when the operating contacts of the switch are opened, the backlight circuit becomes the only path through which current can pass.

It should be noted that when choosing a switching device designed to work with energy-saving lamps, you need to pay attention to the backlight elements. If it uses an LED, the lamp in the luminaire may flicker slightly when turned off.

Very often you need to independently branch out the wiring around the house, install sockets and switches. The main thing is to have instructions and a diagram of correct installation on hand. Since connecting a light switch with your own hands is very simple, everything can be done without the help of specialists.

Kinds

There are different types of light switches that are used to control lamps in an apartment or house. Let's look at the main ones:

1. Single-key;
2. Two-key;
3. Three-key;
4. Sensory;
5. Remote.

The one-key light switch is the simplest of the existing ones. A metal bracket is installed into the device body using a screw connection. It controls the switch plate. On the sides of the bracket there are tabs, with the help of which the entire structure is installed in the box. There is also a compartment with wires in the case.

A two-key switch consists of two single-key switches in one housing. A special feature is the larger number of wire groups. You can connect chandeliers with many bulbs or several lamps in different rooms. Three-key models also have a similar design.

Photo - one and two keyboards

The touch model works due to an electrical circuit built into the body. Often equipped with a diode, backlight or switch off control. The box contains a special infrared indicator that recognizes the heat of the human body and closes the lamp contacts. The model with indicator is often used in public places.

Photo - touch

The remote control is perfect for controlling the lighting of a large house or apartment. It consists of a switch equipped with a signal receiver and a control unit. You can turn the light on and off directly from the unit or using the remote control for this purpose. Mainly used in various complexes, as well as in the Smart Home system.

Photo - remote

How to connect a single-key

To work, you will need the selected switch, junction box and lamp to which the connection will be made. Directly connecting a one-button model is very simple. How to connect a single-key light switch to one light bulb:

1. The phase wire of the power supply must be connected only through the contacts of the switching device, otherwise the lamp will always be energized, which is very dangerous. The phase is always connected to the break. Very often, home craftsmen install a break connection on the neutral wire, which can cause a short circuit or even a fire;
2. Next, connect the wires of the wall light switch and the lighting fixture in series with the power supply. Power phase - to the switch, lamp zero to phase zero, lamp phase to switch zero.

Photo - connecting a one-key player

It is more difficult to establish a connection for several lamps. There you need to take into account the phase wires of several consumers at once. Just be careful and strictly follow the announced scheme. It works as follows: when the light switch is turned on (up position), electric current begins to flow to the lamp. If the key is lowered, the chain breaks and the flow of directed particles stops.

Connecting a two-key model

A standard two-button light switch is designed to control various lighting devices or multiple groups of one lamp from a single location. Most often they are used if the chandelier has more than 2 lamps (5.6). In this case, you need to know that two keys are used to control only two groups; if the lamp is divided into more of them, then you need to use a triple switch.

Photo - connecting a two-key model to a chandelier

How to connect a two-key light switch yourself:

1. This model has three contacts - an input and two outputs. In this case, the phase from the distribution box is connected to the input contact, and the outputs are needed to control individual groups of the chandelier;
2. You need to insert the phase wire of the network and its zero into the distribution box;
3. First of all, all neutral conductors are connected to each other. The phase one is connected to the input of the electric light switch;
4. It also has wires for each group of lamps. They are most often separated by color coding. In order for each group to burn independently of the other, each must be connected to a separate phase wire. For example, yellow and gray cables: yellow is assigned to group 1, and gray to group 2;
5. The neutral wire of the switch is connected to the zeros of the lamps and the network;
6. All that remains is to isolate the conductors.

In this case, a double light switch can be connected so that when one group (main) is turned off, the second (additional) is also turned off, then the circuit will be slightly different. It is necessary to switch the device not each group separately, but both at once. The triple can be connected in a similar way. The main thing is that when the keys are turned off, the phase is disconnected, not the zero.

It is also very often necessary to connect the switch to a sconce lamp and socket. This greatly saves space in the room allocated for electrical outlets. Then the diagram looks like this:

1. The socket is installed parallel to the supply wires. The phase corresponds to the network phase, and the zero corresponds to zero;
2. The procedure for turning on the lamp does not change; we do everything as described above.

In this way, you can install a model produced by Legrand, Viko, UAZ or any others.

How to install a gateway

Nowadays, it has become very popular to install switches that allow you to turn off one group from different parts of the room. Let's look at how to properly connect pass-through light switches:

Photo - connection diagram for pass-through switch

1. The diagram takes into account the connection box, since without it it will be difficult to make a connection;
2. You need to bring the phase neutral wire into the junction box and connect it to the lamp neutral. The central phase cable is connected to the input contact of one of the switches to choose from;
3. After this, two switched contacts of one switch must be connected to similar terminals of the second;
4. Now, after connecting the switches, the phase from one (to which it was previously connected) is transferred to the second. Everything is placed in a box and closed.

Photo - operating principle of the walk-through model

Be sure to insulate all contacts, otherwise they will short out. Many experts recommend using soldered contacts - it is more reliable and durable than electrical tape.

Almost any room uses electric lighting, and switches are used to control it, so sooner or later there is a need to replace them or install new equipment. From an electrical point of view, there is nothing complicated about this, but in order for the circuit to work reliably and safely, and in the future to be convenient to maintain and repair, you need to know some of the subtleties characteristic of this type of work.

Single Key Light Switches

Important! Before carrying out installation and connection work, be sure to turn off the voltage in the distribution box, then use an indicator screwdriver to check whether current is flowing to the place where the work is being performed.

Checking with an indicator screwdriver is mandatory, since switchboards often use single-pole circuit breakers that break only one wire. If such a machine was mistakenly installed in the neutral wire, then after it is turned off, the current will still flow through the wires.

Lighting is used in a wide variety of spaces and environments. Various types of light sources are used. Therefore, there are a wide variety of types of switching elements. A single switch is the simplest type, but once you understand it, you can connect more complex elements.

If we consider a switch as an element of an electrical circuit, then it is an open contact that has only two connectors for connection. Most often these are screw connections, that is, the connected wires are clamped with screws using a screwdriver. Self-clamping connectors may also be found. To connect to them, you need to strip the conductor of insulation and insert it all the way into the corresponding hole.

According to the installation method, they are divided into two groups:

• external;
• internal.

An external single-key switch is installed directly on the wall surface, and an internal one - in a special mounting box located inside the wall.

What's the best way to install a light switch?? There is no clear answer here, because each installation method has its own advantages.

It is better if all the elements are installed inside the wall, since in this case the conductive parts will be hidden and protected from damage, which will protect you from electric shock. But to do this, it is necessary to punch paths in the wall for laying wires, recesses for installing mounting and junction boxes, and then re-plaster the walls.

All this work is very labor-intensive and is not required in the case of external installation, when all elements are attached to the wall surface, and the cables can be hidden in a special box or protective corrugated tube.

Replacing the old switch

First, let's consider the case when a repair is being carried out, and it is necessary to replace a faulty switching device with a new one, but the cables and other elements are in good condition. The biggest difficulty here is how to disassemble and reassemble the switch.

If the switch is outdoor, locate the screws that secure the protective cover.. Unscrew them, remove the cover and remove the screws or screws (usually there are two) that secure the device to the wall, and the terminals will become accessible.

In order to disassemble the internal one, first carefully pry up the key with a thin screwdriver and remove it, after which you can unscrew the screws located under it and remove the decorative plastic panel. There are two screws on the sides that secure the device to the mounting box, loosen them and remove the switch.

After you have disassembled the switch, all you have to do is loosen the screws on the terminals (no need to unscrew them completely) and pull out both wires. It is not necessary to mark the wires; their connection can be arbitrary.

Disassemble the new switch, connect to the wires and reassemble by performing the above steps in reverse order. Particular attention should be paid to tightening the screws on the terminals; loose tightening may lead to heating of the connection point and cause a fire.

Description of the connection process

Now let's look at how to properly connect a light switch from scratch. The connection diagram for a single-key switch is simple. In order for the lamp to light up, two wires are connected to it - phase and zero. In order for the light to be turned off, you need to cut one of the wires and connect a switching device into this gap.

When replacing lamps, you may touch the live part of the socket and receive an electric shock. To avoid this, be sure to install the switch in a phase wire break.

Regardless of the installation method, in practice it looks like this:.

1. The main cable is laid, which goes from the power source to the lamp. It is located along the wall at a distance of 150 mm from the ceiling.
2. The wire from the switch is routed vertically upward.
3. At the intersection of the supply wire and the wire coming from the switch, a junction box is installed in which all the necessary wire connections are made.

Now you can start assembling the circuit. The wiring will be done with a two-core cable. For the convenience of performing this operation, the length of the wires coming out of the box is made such that their ends extend out of it by 20 centimeters; the wires that will connect the remaining elements of the circuit are made of the same length. The ends of the wires are stripped of insulation. Connections are made in the following sequence:

Connection of conductors

There are several ways to connect conductors in a box:

• If single-core aluminum or copper wires are used, they can be twisted together and insulated with PVC tape, and the length of the twist must be at least 25 mm.
• If the wires are multi-core (each wire consists of a large number of thin wires), then they are connected using special terminals. If the terminals are closed, then there is no need to insulate them. The choice of terminal type is quite wide, but the main requirement for them is to ensure reliable contact at the connection point. In addition, when choosing, it is necessary to take into account the cross-section of the wires.
• If the wires are copper, they can be connected by soldering, and the soldering area can be insulated.

Please note that copper and aluminum wires should not be connected together. Such a compound quickly oxidizes, begins to heat up and becomes a fire hazard. If necessary, use a terminal block where the copper and aluminum will not touch.

Connecting multiple lamps

You can connect two light bulbs to one switch. To do this, they need to be connected in parallel and connected to the wire going to the lamp. The number of lamps with this connection is limited only by the rated current of the switch itself, but all lamps will turn on and off simultaneously. For separate operation it is necessary to use other switching elements.

If, for ease of use, you decide to install a backlit switch, then you must take one point into account. Many modern energy-saving lamps and LED-based lamps will flash periodically with this design, and you will have to either change the lamps or turn off the backlight.

In conclusion, I would like to remind you once again about strict adherence to safety regulations at all stages of the work. Pay special attention to the reliability of the connection of conductors and the insulation of these places.

Lighting in an apartment is an important component of all home electrical wiring. In turn, it is difficult to imagine lighting without switches. Therefore, installing a switch is a fairly popular type of electrical installation work, which will not be difficult to learn. In this article we will take a closer look at how to connect a switch with your own hands.

Types of switches

Modern switches are classified into several types.

By design:

• single-key;
• two-key.

By installation method:

• internal;
• external.

The choice of which one to install depends on the type of electrical wiring you have and the type of fixture.

Features of connecting the switch

A switch is a switching device for closing and opening an electrical circuit by breaking a phase.

Therefore, it is the phase wire that must pass through the switch, not the neutral wire, which must pass to the installation site of the lamp directly from the junction box.

In some apartments, incorrect connections sometimes occur. This is fraught with the fact that when the light is turned off while replacing the light bulb, an electric shock may occur, since instead of a phase, zero is disconnected, and the light bulb socket is energized.

If such an incorrect connection is detected, the phase phase of the wires should be changed. To do this, you need to change the circuit in the distribution box to the correct one.

When installing this device, the question arises at what height to install it, are there any rules and standards. According to the rules for electrical installations:

• It is recommended to install switches on the wall on the side of the door handle at a height of up to 1 m; they can be installed under the ceiling with control using a cord.
• Any switches and sockets must be located at a distance of at least 0.6 m from the doorway of the shower stall.
• The minimum distance from switches, sockets and electrical installation elements to gas pipelines must be at least 0.5 m.

In Soviet times, there were slightly different requirements for what height to install switches in an apartment. The standard height was 1.6 m. Therefore, in many apartments they are still located “at eye level”.

Preparation of the workplace

When performing any electrical installation work, first of all, it is necessary to turn off the power supply, check that there is no voltage, and exclude the possibility of unauthorized re-switching on the voltage. Using a voltage indicator, determine which of the wires in the junction box is phase and mark it with a marker.

Prepare the necessary tools:

• pliers;
• voltage indicator;
• screwdriver;
• construction knife;
• marker.

This type of switch is installed in apartments with internal electrical wiring, that is, all wiring is hidden in the wall.

At the location where the socket is installed there should be a recess in which a special box for the switch is installed, into which the wire is routed.

Operating procedure:

1. Preparing the switch for installation. It is necessary to disassemble the switch; to do this, unscrew the screws connecting the button to the frame and remove it from the frame.
2. Trim the insulation from the wires where they connect, leaving about 1 centimeter of exposed area on each.
3. Insert both phase wires into the holes for the wires: the one coming from the distribution box into the inlet hole and the one coming from the switch to the installation site of the lamp into the outlet hole.
4. Tighten the screws tightly to securely fix the wires, which should not move freely.
5. Install the mechanism in a special box in the wall and securely fix it to avoid loosening.
6. Install the previously removed frame onto the mechanism and secure it with screws.
7. Install switch keys.

If we are not talking about replacement, but about installing a new switch, it becomes necessary to install a special box for the switch. This is done as follows:

1. At the location where the electrical wiring switch is installed, make a niche in the wall slightly larger than the size of the box.
2. Lead the phase wire through the hole in the bottom of the box. Secure the box in the niche using any plaster solution.

Connecting an external single-key switch

If home electrical wiring is done in an open way, that is, on top of the walls, then external switches are used. In this case, a box for the switch is not used; the switch is mounted directly on the wall using self-tapping screws, and in some cases, dowels.

Operating procedure:

1. Disassemble the switch. To do this, remove the keys from it and unscrew the screws securing the mechanism to the body.
2. Having cut off the insulation at the ends of the wires, insert the phase wire coming from the junction box into the inlet of the mechanism, and going from the switch to the installation site of the lamp into the outlet.
3. Tighten the screws to securely fix the wires.
4. Attach the socket box with the mechanism to the wall and connect it to the switch body. Some models of switches come without a socket box, in which case the mechanism is mounted directly on the wall.
5. Set a key.

Connecting a two-gang switch

Installation of this type of switch is used in the following cases:

• The chandelier shades are divided into sections to regulate the level of illumination, each section is connected to a separate switch button.
• The switch is connected to autonomous lamps.

If with a single-key switch everything is clear and simple, then connecting a two-key switch seems much more complicated: the terminal box is different and there are more wires. In fact, this should not cause any big difficulties, the connection algorithm is the same. The device is not much different from a single-key device.

Operating procedure:

1. Disassemble the switch. The mechanism is somewhat different from the single-key mechanism. But there’s nothing wrong with that: in modern switches, all contacts are marked. L - contact for the supply phase, outgoing contacts are indicated by downward arrows.
2. Having cut off the insulation from the wires at the point of their connection, we connect the wires to the corresponding contacts of the mechanism.
3. When installing internally, secure the mechanism in a special box in the wall and put on the previously removed frame. For outdoor use, mount it on the wall and install the switch housing.
4. Set keys.

Connecting an illuminated switch

Who, at least once, while searching for a switch in complete darkness, did not trip over shoes and other objects lying on the floor, and, swearing, barely fumble for the treasured button on the wall? This situation is painfully familiar to everyone. Therefore, to make searching easier, an illuminated switch was created. When the light is off, the indicator lights up and indicates its location.

Principle of design and operation of an illuminated switch

Unlike a conventional one, a backlit switch is equipped with a light indication; the indicator is a neon lamp or LED connected in parallel to the contacts of the device and a current-limiting resistor that reduces the voltage in the network.

When we turn off the light, a phase break occurs in the switch contacts going to the lamp. But at the same time, the circuit to which the indicator LED is connected is not broken. The resistor lowers the incoming voltage to the minimum required to turn on the LED.

When the light is turned on, the indicator turns off. This occurs because the current follows the path of least resistance. The lamp is connected to a wire with a cross-section much larger than that of the wire going to the LED, which means the resistance is much less.

A reasonable question arises: if the indicator LED lights up, it means there is voltage, then why doesn’t the lamp in the lamp turn on? It's all about the resistor through which current passes to the LED. It lowers the voltage to a level that is not enough to turn on a light bulb in a chandelier, but enough to turn on an LED.

Connecting an illuminated switch is the same as a regular one.

It is not recommended to connect an illuminated switch together with fluorescent or LED lamps equipped with a ballast. The reason is that when the switch is off, the current flowing through the LED to the lamp charges the filter capacitor, which does not need much current to charge. The capacitor, in turn, tries to turn on the energy-saving lamp startup circuit. However, there is not enough charge on the capacitor, it discharges, and the lamp goes out again. And this can continue indefinitely.

Therefore, the backlit switch is installed only on incandescent or halogen lamps.

You should also pay attention to the fact that if the lamp is missing or burnt out, the backlight will not work. For the simple reason that an LED indicator needs both zero and phase to light up. And the zero to the indicator comes from the switched off chandelier on the ceiling. If the lamp is missing, then the power circuit is broken.

Compliance with safety regulations

Well, we’ve figured out how to install switches - one of the simplest electrical installation jobs that does not require special skills and talents. If you study everything in advance and understand what, how and why exactly this is done, then you can easily and quickly carry out this hitherto unfamiliar procedure for installing a switch.

And one of the most important points is compliance with safety precautions, otherwise the current strength will test your strength. And there are not so many safety rules:

1. Before starting work, stop the power supply by turning off the circuit breakers in the electrical panel. Take measures to exclude the possibility of re-applying voltage.
2. All tools must be in good working order. It is necessary to check for damage and chips on the insulating parts of the instruments.

Light switches are one of the most common electrical installation products. Every apartment, house, office has at least a few of them. To save space and reduce the amount of work, switches can have not one key, but two or even three. But double ones are still more popular. That’s why we’ll talk further about dual (with two buttons) switches. They are also called two-key, two-button, double, etc. Connecting a double switch is quite possible for a novice electrician. Even without special skills, you can handle this yourself.

If you need to connect two light bulbs or two groups of lamps, and it is necessary for them to turn on independently of each other, you need a two-key switch. They are very easy to distinguish - two buttons are installed in one housing. By the way, the presence or absence of backlight does not affect the connection in any way. Neither the schemes nor the principles change.

The circuit of a two-key switch is simple: these are two normally open contacts, each of which is controlled by its own button. This means that in the initial state no current flows through the switch, since the contacts are open. By pressing the key, we close the contacts, the lights light up. This is the operating principle of any switch. The two-key one differs only in that it has two groups of contacts.

If you look at the design of a two-button switch, we see that it has one input and two outputs. The phase is connected to the input of the switch, and the wires that go to the light bulbs/chandelier are connected to the output.

Safety precautions - be careful

Connecting a double switch yourself is not difficult. You can cope even without special knowledge and skills. But you have to be extremely careful - it's still electricity. We must follow safety precautions. Things to remember:

The easiest way to check is to use an indicator screwdriver. If you touch a live wire with it, the signal light on it will light up. This is how the phase is determined. If the light does not light, it is the neutral or the wires coming from the light bulbs/chandelier. Only after understanding all the wires can you begin to connect the two-key switch.

Connection diagrams for a two-key switch

When connecting the switch, remember that the phase that comes from the panel is supplied to its input. This is the basic rule. This is the only way the connection will be correct. The phase is taken in the distribution box, which is usually located above the switch (sometimes, with lower wiring, below it) in the distribution box.

Please note that work is carried out with the voltage turned off. If there is a circuit breaker through which the lighting is powered, turn it off. If the wiring is old, unscrew the plugs. Before work, make sure that there is no voltage on the wires (touch all with an indicator screwdriver).

To two light bulbs

Most often, two loads are connected to a two-key switch - one light bulb or a group of lamps. In any case, the scheme will be the same.

A phase wire is connected to the input of the switch. The contact at the top of the switch is loosened (turn the bolt a couple of turns counterclockwise), the wire stripped of insulation is inserted along the plate (stripping 4-6 mm), the mounting screw is tightened. When tightening the bolt, apply considerable force. You can check whether the wire is securely fastened by tugging it well a couple of times. If you can’t get it, everything is fine.

In the same way, connect two wires that were sewn from light bulbs/chandeliers. The contacts to which you need to connect are located below. The principle is the same - loosen the screw, insert the wire, tighten it, pull it.

It doesn’t matter where to connect which wire (to the right or left contact). It just depends on which key will turn on which light bulb. If desired, they can be swapped later.

After the connection is completed, install the keys, turn on the power, and check the operation of the switch. If everything is done correctly, there should be no problems.

In addition to just switches with two keys, there are blocks with a socket. In this case, the connection of the double switch does not change, but a zero and grounding must be added to the socket.

So, we supply a phase to the block of switches, and from the output of the switches the phase goes to the light bulbs. We supply a phase to the socket block (you can take it from the entrance to the switch block), set “zero” to the second contact - from the corresponding bus on the panel. We connect the ground to a special ground contact.

What to do if there are more wires

In the double switch connection diagram described above, three wires are needed - a phase from the distribution cabinet and two wires from the light bulbs. But sometimes four or more come. What to do then?

• Find the phase and mark it. It is advisable to bend it so as not to touch it in the future.
• Find two wires that go to the light bulbs. This can be done using dialing mode.
• The remaining wire is most likely ground. According to the new standard, it is required even when connecting light bulbs. If you have a ground wire on your chandelier/light bulbs and it is connected to the switch, then we simply twist both wires. If the light bulbs or chandelier do not have an “earth” wire, simply insulate the wire and leave it. There is no need to cut it off - maybe later buy a chandelier with an “earth” wire.

There is a weak point in the specified algorithm - we assumed that the remaining wire is ground. Logically, this is correct. But, unfortunately, there are exceptions. Therefore, before manipulation, you should decide whether this is really “earth” in front of you. To do this, you can measure the voltage using a multimeter (set the measurement limit to 1000 V - just in case, then you can reduce it). We touch the phase one with one probe, and the nameless one with the second. If it shows 220 V or a figure close to it, this means “zero” and not “ground”. If the readings are lower than 220 V, this is “ground”.

This “measuring device” can determine the “zero” or “ground” of your unknown wire

If you don’t have a multimeter, you can use a light bulb to which you connect two wires (you can take a table lamp and wrap two wires around the plug). Take single-core wires, rigid, of sufficient diameter. Their ends need to be cleaned, but you will only hold on to the insulation. We touch the phase wire with one end, and the “unknown” wire with the other. If it’s on, it’s “zero”; if it’s off and the machine is knocked out, it’s “zero.” This method is dangerous to health, so we act very carefully.

If the connection is incorrect

If you decide to replace the old switch with a new one, and not a phase, but a zero is connected to the old one, this is wrong and you need to fix everything urgently. The light bulbs will work, but with this connection they are always energized. In this case, even replacing a burnt-out lamp is a deadly undertaking. I'm not kidding. This is true. Therefore, if the switch is connected incorrectly (if zero comes to it), everything must be corrected. There are two options here:

If you are connecting a double switch with your own hands for the first time, it is better to double-check your actions several times and work very carefully.

Switch installation

Finally, let's talk about how to install switches. It doesn’t matter how many keys they are. The sequence of work is the same:

• From the junction box, lower vertically downwards (or upwards with lower wiring).
• At the selected height, a hole is made in the wall for the socket box. Typically, a drill attachment is used - a crown.
• A socket box is installed in the hole. The voids between the socket box and the wall are filled with a solution, preferably with good adhesion to concrete and plastic.
• A small diameter corrugated hose is laid from the distribution box to the entrance to the socket box. Wires are then passed into it. With this installation method, it is always possible to replace damaged wiring.
• The switch is disassembled (the keys and decorative frame are removed) and the wires are connected.
• Installed in the socket box, secured with spacer tabs, tightening the fixing bolts.
• Install the frame, then the keys.

This completes the installation and connection of the double switch. You can check your work.