How to connect a double switch to two light bulbs: diagrams + connection tips

Living comfort consists of many components, among which lighting system control plays an important role. It can be made more convenient by installing two-key electrical appliances.

Agree, it would be nice to learn how to do this kind of work yourself, especially if you have to do a major home renovation and update the electrical wiring. But before you connect a double switch to two light bulbs, you need to decide on the circuit and study the procedure.

We will help you achieve your plans. The article describes the nuances of implementing different connection schemes, and also provides step-by-step instructions for installing a two-key switch. The text material is supplemented with visual illustrations and video reviews.

Pros and cons of dual connection

An experienced electrician begins any project to improve a lighting system by optimizing the use of all electrical devices combined into one chain.

An example of an optimized circuit is the traditional lighting arrangement of the “toilet + bathroom” block. On the corridor side, one switch is usually installed, but with two keys.

Thus, the lamp in the bathroom is controlled by one key, and the light bulb in the toilet is controlled by a second. With one movement of your hand, you can perform two actions at once, turning off the lights in one room and turning on the lights in the next one, which is very convenient.

If the switch is installed in the wall between two parts of the bathroom, then choosing a key will not be difficult - it will be located on the side of the desired room

Installing a common switch for two rooms is advisable if they are located nearby. For rooms remote from each other, it is reasonable to use separate electrical installations.

A double switch may also be required when installing a chandelier or sconce with two bulbs. Separate control expands the functionality of the lighting device and allows you to increase or decrease the combustion intensity.

If you press one key, the lighting will be inadequate; when you press both keys, it becomes twice as bright.

To save energy, it is not necessary to use both bulbs at the same time. To create a relaxing atmosphere, it is enough to turn on only one of them

As you can see, the ability to connect a double switch to two separate light bulbs makes it easier to control lighting fixtures or adjust light intensity. When installing a single device for two rooms, not only electricity is saved, but the number of installation materials and devices is reduced.

How to choose a circuit for two light bulbs

There are differences in the connection of 1-key and 2-key switches. To better understand the difference, let's first look at the installation nuances of a single-keyboard player.

You can connect one or more light bulbs to a regular switch with a single key - the principle remains the same.

The diagram shows an option using a two-core cable, without using ground.The neutral core is pulled directly to the lighting fixture, and the phase is connected to the switch, from where it goes to the light bulbs (+)

This is the simplest scheme; it is traditionally used if simple control of a lamp or an entire group is needed. When the electrical installation is turned on, all involved light sources light up. If there is a chandelier or sconce with two lamps, then both will turn on at once; it will not be possible to use them one at a time.

Now let’s look at what changes if a single-key device is replaced with a two-key device. The first circuit for connecting a double switch to two separate light bulbs is relevant for the TN-C system, which is still found in old houses. For the lighting circuit, two-core wires are used.

The zero is sent through the junction box directly to the lamps connected in series, and the phase goes to the input terminal of the switch. But the output is already double: a phase conductor goes from each of the output terminals to a separate lamp (+)

It turns out that you can use either one or both light bulbs at the same time, using either one or two keys.

A positive point is the ability to change the lighting intensity in one room. If the lamps are in different rooms, then you can turn on the lights in each room separately or in both at once.

In new houses, grounding systems that differ in design are used, for example, TN-S. The difference between the second scheme for a home electrical network is that a three-wire wire is required: the third wire is the “ground”.

Like the neutral conductor, the grounding conductor is sent to the distribution box, and then connected to the wires of the lamps and connected to metal parts (+)

The grounding wire is connected differently if there is an outlet in the same block as the switch. Then the “ground” from the electrical panel reaches to the distribution box, and from there to the outlet.

Step-by-step installation instructions

Conventionally, connecting a switching device can be divided into several stages. They start with the cables: if the wiring is old, then it definitely requires replacement.

Then you need to correctly connect the wires in the junction box, and finally in the switch mechanism. To install a chandelier or lamp, you usually use the instructions provided by the manufacturer.

Stage #1 – preparing the walls

Stage wall gating It is recommended to skip only if new wiring with copper conductors of a suitable cross-section has already been laid. When in doubt, it is best to consult an electrician.

For the lighting group, a regular VVGng wire with a cross section of 1.5 mm² is suitable. If sockets are connected along with the lighting, then it is better to immediately take the same wire, but 2.5 mm².

The preparation of the walls includes gating, arrangement of installation sites for socket boxes and distribution boxes. At the same stage you can install additional circuit breaker to the electrical panel.

A separate protective device will come in handy when the lighting line requires repair - only one circuit can be turned off, the rest will work as usual.

The grooves are knocked out with a hammer drill, a circular saw, or even manually, but to cut even grooves, a special tool is used - a wall chaser equipped with a vacuum cleaner

System wooden house lighting differs in the type of wiring. The hidden method is not used, since it is extremely fire hazardous and requires maximum cable insulation.

The wires are mounted from the outside on special insulators. Instead of internal switches, overhead switches are installed, but the principle of connecting the cores to the terminals does not change.

After gating of concrete, brick, and aerated concrete walls, the grooves in which the wires are laid are sealed with mortar or alabaster. Then you can plaster and decorate the walls, but it is better to save the location of the wires in a drawing or diagram - until the next repair.

Stage #2 – connection in the distribution box

The distribution box is the chamber where the wiring and connection of the wires takes place. When installing switches or sockets of different types, the connection diagram changes.

But first you need to get it right choose a junction box. Previously, metal products were used, but now they produce safer and easier-to-install plastic analogues.

There are internal and external models, but it is always easier and more efficient to work with external ones. If you need to urgently disconnect the wires due to replacing the electrical installation, then to access the built-in junction box you will have to dismantle the plaster and then make repairs.

The body of the external model is always visible: just unscrew the cover and perform the necessary actions.

The connection diagram of the cores is simple: the neutral wire from the panel is twisted with the zeros of the two connected lamps, and the phase is sent to the switch. Two output phases from the switch go to the lamps - one for each

If the wire is three-core – and now this is what is most often used – then in the junction box, similar to the neutral conductor, the “ground” is twisted.And if the wiring is old, but reliable, then there is no point in changing it, and you need to use the connection indicated in the schematic image.

There are several ways to connect wires. The most common are twisting followed by insulation and use of terminals.

Soldering is used extremely rarely. If you are used to using terminal blocks, then you can consider the option of a distribution box with pre-installed terminals.

Stage #3 – installation of lamps

How it is produced chandelier installation with two lamps or two separate lamps, depends on many factors:

• lighting fixture models;
• wiring readiness;
• basics for installation.

The easiest way to change lighting equipment is when the wire is routed out at the installation location, for example, in the center of the room.

To install a chandelier, you need to perform two operations: hang the lighting fixture on a hook or bracket and connect the wires correctly

If the ceiling is new and is a suspended structure (tension, plastic or plasterboard), then additional fasteners or mortgages should be installed to install the chandelier.

When two phase wires are supplied from a two-key switch to the lamp, they are connected alternately - each to its own lamp. Also, two neutral wires are pulled from the distribution box - they are also scattered among different lamps.

If both bulbs are connected to the same wire, they will turn on/off at the same time, and there is no point in installing a double switch.

When installing two separate lamps in different rooms, the connection principle remains the same, only the routing of the wires from the junction box changes - they are directed in different directions. As a rule, the rooms are located next door.It is better to mount the distribution box above the switch, approximately 15-20 cm from the ceiling.

Stage #4 - installation of the switch

There are no difficulties in either installation or connecting the two-keyboard. It is installed in a socket box or directly into the wall, secured with claws or a screw connection. Exactly how the wires are connected is shown in the photo.

The double switch is always connected only to the phase conductor coming from the distribution box, where it comes from the electrical panel. The core is inserted into the terminal marked “phase L”. From the output contacts L1 and L2, the phase conductors go to the lamps (+)

If the chandelier has not two, but more lamps, which is much more common, then the connection is made in groups. All lamps are divided into two equal or unequal groups, and then the wire from contact L1 is directed to one, and the wire from contact L2 to the second.

Conditional division into groups is made depending on the desired degree of illumination of the room. If you need two intensity modes, weak and bright, then you can connect the first core to one lamp, and the second to the rest. To reach the maximum brightness level, just press both keys.

General recommendations and useful tips

There are several important points that should not be forgotten. They relate to both installation work and equipment selection.

Following simple rules will make the system more secure and reliable, which is important for a closed network.

Do not forget that any actions with electrical devices and installations are carried out only after a power outage at the general apartment switchboard. Before each operation with wires, make sure that the circuit is de-energized.

If, instead of a conventional two-key switch, you want to install a non-contact type switch or a device with dimmer, be sure to study the diagram, since the installation of such devices may differ.

Conclusions and useful video on the topic

It is best to imagine how to properly connect wires and install devices by watching a training video.

Two-keyboard for two lamps:

Nuances of connecting a chandelier:

Useful connection tips:

The procedure for installing and connecting a double switch can be performed without the involvement of a qualified technician, but during work you should remember the safety rules. Before electrical installation work, it is necessary to take into account all factors and choose the right circuit.

Do you have anything to add or have questions about connecting a double switch? You can leave comments on the publication and participate in discussions. The contact form is located in the lower block.