Installation and connection of a two-gang light switch is relevant in cases where it may be necessary to change the intensity of lighting in a room or control the illumination of various areas of the interior. You can adjust the amount of light by changing the number of working lamps using such a device. Since this product has two keys, it is able to control the operation of two groups of luminaires. As a rule, two-gang light switches are installed in conjunction with chandeliers that have more than two bulbs in their composition.
Another situation in which the use of such devices is preferable is when they are used to turn on lights from one location in different rooms or corridors.
It must be said right away that the connection diagram of a two-gang switch is in many ways similar to a similar circuit used when installation of single-key models.
Thus, the scope of such devices is very extensive, but in all cases the same scheme for their connection is used. In order to figure out how to connect a two-gang switch, you should familiarize yourself with its device and the principle of operation.
Double switch design
The classification of these devices is quite simple. There are built-in and overhead models designed for use, respectively, with hidden or open wiring. Among the additional features that these devices can be equipped with, one can highlight the backlight. Illuminated switches are easy to find in a dark room, so they are very convenient to use.
The design of a two-key product is quite simple and is in many ways similar to the internal structure of a single switch. The only difference is that there is a separate contact designed to power the second group of consumers. Structurally, a two-button switch consists of the following main elements:
- Working part. Unlike single-key models that have two terminals, this switch has three contacts. One of them is incoming and two are outgoing. The input contact is designed to connect to it a phase wire coming from the junction box. The outgoing contacts of the working part are used to connect wires to them, which are used to power consumers. As a rule, the body of the working part of the switch is marked, which makes it easier to determine the type of each terminal. This part of the device design must be installed in such a way that the common terminal is located at the bottom.
- Decorative frame.
- Two keys (can be equipped with windows for illumination).
If the design of the device provides for backlighting, then it includes a small electrical circuit that includes an LED (or neon lamp), a resistor, and sometimes a capacitor. This electrical circuit is connected to the contacts of the switch. The principle of its work is quite simple. Since the current-limiting resistor has a sufficiently large resistance, when it is short-circuited by the short-circuited contacts of the switch, no current flows in the backlight circuit. When the working contacts are opened, a small current, limited by the resistance of the resistor, flows in the backlight circuit, ensuring the burning of the LED.
Illuminated switches have become very widespread at the present time.
General connection diagram
The connection diagram of a two-gang light switch is shown in the figure.
The ground wire, which is shown in the figure, is not present in the wiring of all buildings.If, in order to connect powerful household electrical appliances, such as a hob or a washing machine, they try to ground their cases at least to the electric meter shield, then there is usually no grounding in the lighting circuits. To increase the safety of using wiring in such conditions, it makes sense to install at the entrance to the apartment residual current devices or differential automaton.
The double switch connection diagram shown in the figure has two separate lamps as a load, however, such a connection is often used to control each switch key with a chain of several lamps connected in series.
How to connect a device
The main rule that must be observed when installing all switching devices is the need to install them in such a way that when disconnected, the phase wire circuit breaks. This should be done in the first place, so that when changing the light bulb, it is enough to simply turn off the switch without resorting to the use of an introductory machine.
The fact is that a large number of cases of electric shock to a person occurs precisely during the performance of such work. Such cases, unfortunately, often occur, despite the fact that in order to create a dangerous situation, it is necessary not only to confuse the wire on which the switch should be installed, but also to connect the bulb holder incorrectly.
As for working with any elements of electrical wiring, when installing and connecting two-gang switches, you should follow the safety rules, the main of which is the need to turn off the mains voltage for the duration of the work. Since junction boxes are in most cases located at a height, an important element when working with them is the use of a reliable ladder or stand.
In order to properly install such a device, you must adhere to the following procedure:
- With the help of the input machine, the power supply to the apartment is turned off. This can also be done using an automatic machine responsible for the consumer group, which includes the necessary lighting circuit.
- Wires coming from consumers that need to be connected to the network, phase and zero from the input shield, as well as three wires coming from the switch are brought into the junction box. It should be borne in mind that, if it is necessary to connect copper and aluminum wires, terminal blocks must be used. This situation occurs quite often in old houses, where internal wiring was carried out with aluminum wire.
- All neutral conductors in the box are interconnected.
- The phase wire coming from the entrance to the apartment is connected to the conductor, which will be connected to the input terminal of the two-gang light switch.
- Each of the phase wires used to power individual consumers is connected to the corresponding outgoing wire of the switch.
- All connections are securely insulated. To insulate the connections in the junction box, it is preferable to use fiberglass tape, as one of the most resistant to temperature effects.
- Its keys are removed from the switch, after which the working part is disconnected from the frame.
- Corresponding wires are connected to the contacts of the working part. For convenience, it is desirable to use cables whose cores have different color markings. If the design of the device provides for backlighting, then the contacts of its circuit are connected to the terminals of the switch.
- With the help of sliding legs, the working part is installed in the socket.In this case, it is important to ensure that the on position of the device corresponds to the pressing of the upper part of its keys.
- With the help of special grooves or bolts, a decorative frame is mounted.
- Keys are installed.
In practice, connecting a double switch is not much more difficult than connecting a single-key device.
