Convenient two-key switches due to the increase in functional load outperform single-key counterparts. If instead of ordinary single wiring devices to equip the house with double appliances, the savings will be significant.
The connection of the double switch should be in compliance with safety standards and regulations.
In this material we will tell you how the double switch is arranged, name the advantages of such devices, and also give detailed instructions for installation and connection.
How is a double switch arranged?
Not a single device can be connected correctly without first studying its “filling” and the principle of operation. In this sense, circuit breakers are not particularly difficult.
The device of two-key models repeats the design of single-keys, but differs in the number of terminals and the connection principle. The external difference is reflected in the name of the model - it has two separate keys, each of which controls the electrical circuit.
The switch can be divided into two parts: external and internal. The first consists of a decorative frame and keys - the main tool for managing light sources. They simultaneously protect work items. The second is an internal mechanism with terminals
In the manufacture of devices using metal and plastic parts. In particular, conductive metals such as steel and copper are used for contacts.
In order to better consider the individual elements of the switch, we will understand how the disassembly and connection occurs.
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Most often, external parts are made of plastic - a safe material that does not conduct electricity. When dismantling or disassembling, they are removed first, and during installation they are fixed, on the contrary, last
The mechanism is mounted on a metal frame and is a three-dimensional module with several terminals, and sometimes buttons. On the top panel there is a marking indicating the possibility of connecting various wires
If the mechanism is in the socket, then for fastening usually use either spacer tabs located on both sides, or special holes that, when installed, allow you to align the body of the device
The main elements of the mechanism are the contacts, which serve to fix the wires. On the one hand, suitable wires are connected, on the other, outgoing ones. Contacts are self-locking, acting due to the spring, and screw
Decorative part - frame and keys
The inside of the switch is a mechanism
Mounting tabs or screws
Contacts with wiring diagrams
Symbols for which numbers and latin letters are used may differ on different models. For example, L may indicate the total supply phase, while the numbers 1,2 are the outgoing phases. Also, arrows can be used to indicate input / output.
Advantages of Two-Key Models
What is it worth to abandon the familiar and simple single-key devices in the device for the sake of double?
In fact, the benefits are obvious:
- from one device you can control two different lighting devices or two groups of lamps;
- the light intensity in the room can be adjusted, depending on the number of light sources involved;
- due to the selective inclusion of individual fixtures, energy is saved;
- if desired, you can control the lighting mode in two rooms at once (in the kitchen and corridor, in the bathroom and toilet);
- more rationally and economically consumed electric wires.
Adjusting the light is the ability to create a comfortable environment for performing certain actions. For example, to work or read, you can use both keys to turn on all 5-6 lamps of the chandelier. And for relaxation, 1-2 bulbs are enough to create diffused, dim lighting.
Another advantage of modern models is a different design. Due to the color and style diversity, you can choose a device that looks the most suitable for the decoration of the room.
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Double circuit breaker with separate modules
Surface mounted model for wooden walls
Natural or color switches
Like single keys, dual models are built-in and overhead. If the walls in the apartment / house are made of brick, concrete, aerated concrete or drywall, internal switches are usually installed.
Installation of overhead devices is typical for wooden houses, where during the installation of internal wiring, certain difficulties associated with the rules of PUE are expected.
Popular circuit solutions
When choosing a circuit breaker for a double switch, two related factors should be considered:
- which grounding system is used in the house - TN-C or TN-S;
- one or two lighting devices are controlled by a switch.
TN-C is considered an obsolete grounding system. A feature of mounting a switch is that it receives only two wires from the switchboard instead of three.
If you connect two lights to one switch, it will look like this. Please note that the neutral wire (blue) combines the ground and zero. So the third wire is not needed
The houses of the new buildings use the modern TN-S system. Before connecting a double switch yourself, you must make sure that a three-wire wire is stretched from the machine to the place of attachment of the electrical installation.
Compare the difference in connection.
The circuit is characterized in that three conductors, including earth, are stretched from the electrical panel to the junction box. Accordingly, earth is also supplied to each lamp / group of lamps
The presence of a third grounding conductor does not affect the connection of wires in the circuit breaker mechanism: only phase wires, one input and two output, still remain there.
If the lighting devices controlled from one switch are in different rooms, the circuit will differ only in the dilution of the conductors in different directions. Consider the scheme in which one group of lamps is in the room, the second in the corridor.
Laying the wires from the electrical panel and the switch, as well as connecting the wires in the distribution box, occurs according to a similar scheme, but then the wires diverge in different directions
If the machine is connected by a three-wire wire, then the earth joins the grounding conductors of the groups of fixtures and, like zero, is bred in two directions.
Connecting the chandelier to two keys of one switch facilitates installation only by the fact that instead of two wires you have to pull one - from the switch to the chandelier
The appearance of the third grounding conductor does not fundamentally change the scheme: it moves away from the circuit breaker in the panel and in the distribution box it is connected to the ground of two groups of lamps.
The distribution of lamps of one chandelier into groups can occur in different ways, depending on the requirements for lighting intensity. The five-arm device can be divided in two ways: 4 + 1, 2 + 3.
The number of options for connecting a six-arm chandelier increases: 1 + 5, 2 + 4, 3 + 3. That is, the more lamps in the lighting device, the more options for combining them into groups.
Installation and Connection Instructions
The connection process can last up to 15 minutes, if a simple replacement of the old device is required, or several days if it became necessary to lay new wiring.
Material selection and tool preparation
If the house / apartment is being repaired, they try to replace the old aluminum wires with copper wires, which surpass them in all respects. This is regulated by the rules of the PUE.
When choosing a mounting location, do not forget about the recommendations of the PUE: height from the floor - 60-180 cm, distance to the gas pipeline - 50 cm, distance from the jamb - 15-20 cm
Wires must be laid either horizontally under the ceiling, or strictly vertically down to the installation site. This will prevent accidental cable breakage during subsequent repairs.
To work with electrical installations, you will need a hand tool with insulated handles:
- universal screwdriver;
- round pliers;
- pliers;
- construction or office knife;
- indicator screwdriver.
Marking material and protective gloves with insulation are also useful.
If you have to wall the wall, then in advance you need to worry about the presence of a wall cutter, perforator or drill, as well as a gypsum or mortar for puttying the walls
The switch is chosen, focusing on interior design. When buying a new cable, the system load is taken into account. Lighting groups belong to the most low-power sections of the network, therefore, VVG cable 1.5 mm², and preferably VVGng, with polymer protection of reduced combustibility is suitable.
Cable counting is done using a tape measure. To the total length of the wires, you need to add a margin for twisting in the distribution boxes and mounting in the terminals. Read more about calculating the cable cross-section in this material.
About the connection of electrical wires in the distribution box
The first stage is connecting the cable to the machine, which is located in the switchboard:
- working core (red or brown) - to the terminal of the circuit breaker;
- zero (syn.) - to the zero bus;
- grounding (green or yellow-green) - to the grounding bus.
It is recommended that the work with automatic devices located on the switchboard be delegated to electricians who are responsible for the state of the communal building network. It is forbidden to make any changes to the switchboard yourself. We also recommend that you read an article where we examined in detail the color marking of electrical wires. More details - follow the link.
From the switchboard, the wire is pulled to the junction box, and from it to the switch and the lighting device or to two devices / groups. It is very important not to mix up the connection of the wires in the electrical box.
The conductors are connected as follows: phase of the machine + incoming phase of the switch; 2 outgoing phases of the switch to each of the two phases of the fixtures; zero from the shield + 2 zero lamps; ground from the shield + 2 lands of fixtures
As a result, five connections must be made in the electrical box. To do this, use twisting, soldering or a more modern method - terminal boxes.
Wall Mounting Procedure
The switch is mounted in two ways: into a special installation box (socket box) or directly into the wall. The second method is preferable if the device is mounted in a drywall partition. Consider a step-by-step instruction on how to connect and install a double switch on your own.
Before installing the DV, it is necessary to connect all lighting fixtures from the working circuit: one chandelier, a chandelier with a group of spotlights or lamps in different rooms. Without the initial installation of the fixtures, it is impossible to correctly check the operation of the switch.
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We cut the wires so that they do not take up much space in the niche after installing the switch. The ends of the cores are freed from the protective layer by about 0.9-10 mm
We insert the incoming phase wire (red, brown) into the corresponding terminal, on the contrary, there are 2 terminals for the outgoing phases on the other side. Fasten with screw
We find two terminals for the outgoing phase conductors to the fixtures, insert the stripped wires, fix. Outgoing phases are usually pink, red, white or brown.
We check the reliability of the fixation of the cores in the terminals and insert the switch mechanism into the wall or the socket. We fasten on paws or clips. We connect the power, check the tester
We check how smoothly the inside of the switch is installed, for this we use the level. If necessary, slightly change the position of the housing
We fasten the housing with special fixing screws. The switch must sit firmly, otherwise it may slip out of the niche due to active use
Lastly, we insert and snap a decorative plastic frame and two keys. The frame should stand still, and the keys, on the contrary, should move freely
When the switch is fully assembled, once again check its operation, but using the keys. Turn on the machine, press both keys in turn
Step 1 - trimming and stripping wires
Step 2 - connecting the incoming phase
Step 3 - connecting the outgoing phases
Step 4 - mounting the mechanism into the wall
Step 5 - checking the horizontal position
Step 6 - fixing the mechanism in the wall
Step 7 - setting the decorative frame and keys
Step 8 - testing the circuit breaker
It is possible that the lamps do not light up. You will have to disassemble the switch again and make sure that the cores are inserted into the correct terminals. The reason may lie in the improper connection of wires in the distribution box - you have to look into it.
A detailed wiring diagram for the two-gang switch is discussed in this article.
To make it easier to determine the working function of each wire in the future, even during installation, the cores are marked.
Do not forget about security
Any manipulations with electrical installations should begin with turning off the machine, which is located on the dashboard. After that, the presence of voltage in the network is checked again with an indicator screwdriver or a tester - and so every time before you start working with wires.
If the shield is located on the landing, then it is recommended that you hang a warning sign for the duration of the work so that someone does not accidentally turn the switch.
If you begin to comprehend the basics of wiring, do not work alone, but be sure to invite a partner for insurance: he will hold a stepladder and give it a pair of pliers
Protective gloves with insulation can also protect against electric shock, although it is not very convenient to work with wires in them. When strobing and puttying the walls, it is better to use work clothes, comfortable shoes and a mask or respirator to protect the lungs from dust.
Interesting information about how to connect wires, install a switch, connect devices will add to your knowledge of home wiring.
Nuances of connecting a backlit electrical appliance:
Details on the connection of wires in the distribution box:
Connecting a chandelier using soldering:
From choosing a place to connecting to the machine:
Having experience working with electrical wiring, you can easily cope with the installation of a two-gang switch - the main thing is not to make a mistake with the choice of circuit and stretch reliable wires. However, if there is any doubt regarding the connection or connection of conductors, it is better to seek the help of a professional electrician or perform all actions under his control.
Do you have practical skills in connecting two-gang switches? Or have questions about the topic of the article? Please ask them in the comments box, and we will try to respond to them promptly.