How to connect a double switch for two light bulbs: circuit + tips on connecting
The comfort of living is made up of many components, among which an important place is occupied by the control of the lighting system. It can be made more convenient by installing two-button electrical appliances.
To connect a double switch for two light bulbs, you must select a circuit and connect the wires correctly first in the junction box and then in the lighting fixtures and the switch.
Pros and cons of dual connectivity
An experienced electrician starts any project to improve the lighting system by optimizing the use of all electrical equipment combined into one chain.
An example of an optimized contour is the traditional organization of lighting the “toilet + bathroom” unit. On the corridor side, one switch is usually installed, but with two keys.
Thus, the light in the bathroom is controlled by one key, and the light in the toilet is controlled by the second. With one hand movement, you can perform two actions at once by turning off the lights in one room and turning on the lights in the next room, which is very convenient.
Installing a general switch for two rooms is advisable if they are nearby. For remote spaces it is wise to use separate electrical installations.
A double switch may also be required when installing a chandelier or wall lamp with two bulbs. Separate control extends the functionality of the lighting device and allows you to increase or decrease the intensity of combustion.
If you use one key, the lighting will be defective, when you press both keys, it becomes twice as bright.
As you can see, the ability to connect a double switch to two separate bulbs facilitates the control of lighting devices or the adjustment of light intensity. When installing a single device in two rooms, not only electricity is saved, but the amount of mounting materials and devices is reduced.
How to choose a scheme for two light bulbs
There are differences in the connection of 1-key and 2-key switches. To better understand the difference, first consider the mounting nuances of a single key.
One or several light bulbs can be connected to a conventional switch with a single key - the principle will remain the same.
This is the simplest scheme, it is traditionally used, if you need a simple control of the lamp or the whole group. When the electrical installation is turned on, all the involved light sources come on. If the chandelier or the sconce with two lamps, then both will turn on at once, one at a time they will not have the opportunity to use.
And now we will consider what changes if a single-key device is replaced with a two-key device.The first scheme for connecting a double switch to two separate bulbs is relevant for the TN-C system, which is still found in old houses. For the lighting circuit using twin wires.
It turns out that at the same time you can use either one or both bulbs, using either one or two keys.
The positive point is the ability to change the intensity of lighting in one room. If the lamps are in different rooms, respectively, you can turn on the light in each room individually or immediately in both.
In new homes, different grounding systems are used, for example, TN-S. The difference of the second circuit for the home power grid is that a three-core wire is required: the third core is the “earth”.
The ground wire is connected differently if there is a socket in the same block with the switch. Then the "earth" from the electrical panel reaches for the electrical box, and from there to the outlet.
Phased installation instructions
Conventionally, the connection of the switching device can be divided into several stages. They start with cables: if the wiring is old, then it must be replaced. Then you need to properly connect the wires in the junction box, and finally - in the switch mechanism. For the installation of a chandelier or lamp usually use the instructions proposed by the manufacturer.
Stage # 1 - wall preparation
It is recommended to skip the wall stropping stage only if a new wiring with copper conductors of a suitable cross section has already been laid. When in doubt, it is better to consult an electrician.
For the lighting group is suitable conventional wire VVGng with a cross section of 1.5 mm². If sockets are connected with the lighting, it is better to take the same wire, but 2.5 mm².
The preparation of the walls includes strobing, arrangement of the installation places of the floor boxes and junction boxes. At the same stage, you can install an additional circuit breaker in the switchboard.
A separate safety 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 lighting system of a wooden house differs by the type of wiring. The hidden method is not used, since it is extremely flammable and requires maximum insulation of cables.
Wires are mounted from the outside, on special insulators. Instead of internal switches, they install overhead, but the principle of connecting the conductors to the terminals does not change.
At the end of the stroking of concrete, brick, aerated concrete walls, the grooves into which the wires are laid are buried with mortar or alabaster. Then you can plaster and carry out decorative finishing of the walls, but the location of the wires is better to keep on the drawing or diagram - until the next repair.
Stage # 2 - Connection to the junction box
A distribution box is a camera where the wiring and connection of the conductors takes place.At installation of switches or sockets of various types the connection scheme changes.
But first you need to choose the right box. Previously used metal products, now produce more secure and easy to install plastic counterparts.
There are internal and external models, but it is easier and more efficient to work with external ones. If urgent wiring is required due to replacement of the electrical installation, then access to the built-in junction box will have to remove the plaster and then repair it.
The body of the external model is always in sight: just unscrew the cover and take the necessary action.
If the wire is three-core - and now it is most often used exactly - then in the electrical junction box, similarly to the zero 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 diagram.
There are several ways to connect wires. The most common - twisting with subsequent insulation and connection terminals.
Soldering is used extremely rarely. If you are used to using terminal blocks, you can consider the option of junction box with pre-installed terminals.
Stage # 3 - mounting fixtures
How a chandelier with two lamps or two separate lamps is installed depends on many factors:
- lighting model;
- readiness wiring;
- bases for installation.
It is easiest to change the lighting equipment when the wire is laid out at the installation site, for example, in the center of the room.
If the ceiling is new and is a suspended structure (tension, plastic or plasterboard), then for mounting the chandelier, you must install additional hardware or mortgages.
When two phase wires are fed from a two-button keyboard to a luminaire, they are connected alternately - each to its own lamp. Also, two zero conductors are stretched out of the electrical distribution box - they are also scattered across 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 wire pulling from the junction box changes - they are sent in different directions. As a rule, the rooms are located next door. It is better to mount the junction box above the switch, about 15-20 cm from the ceiling.
Stage # 4 - Switch Installation
There are no difficulties either in the installation or in the connection of the double keyboard. It is installed in a podozetnik or directly into the wall, fixed with paws or a screw connection. How exactly the wires join is shown in the photo.
If the chandelier is not two, but more lamps, which is much more common, then the connection is made in groups. All lamps are divided into two equivalent or unequal groups, and then the wire from the contact L1 is sent to one, and the wire from the 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 modes of intensity, weak and bright, then you can bring the first core to one lamp, and the second to the others. To achieve the maximum level of brightness, 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.
The implementation of 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 appliances and installations are made only after a power outage at the general apartment panel. Before each operation with wires, you should make sure that the circuit is de-energized.
If you want to install a contactless type switch or a device with a dimmer instead of the usual two-keyboard, be sure to study the scheme, since the installation of such devices may differ.
Conclusions and useful video on the topic
It is best to imagine how to properly wire the wiring and install the instruments by viewing the training video.
Two keypad for two lamps:
Nuances of connecting chandeliers:
Useful tips for connecting:
The procedure for installing and connecting a double switch can be performed without the involvement of a qualified master, however, during the work, you should remember the safety rules. Before electrical work it is necessary to take into account all factors and choose the right scheme.