How to install a two-way switch yourself

A two-way switch is not only a convenient way to select the level of light in an apartment, it plays an important role in energy conservation.

According to the operating principle, switches can be both with classic keys, which are pressed from top to bottom and vice versa, as well as with touch buttons. There are also non-contact devices.

The design is a hybrid of two single-key switches with a single cabling system and one housing instead of two.

Advantages of double switches

Double switch is convenient as follows:

1. In the cramped conditions of a small apartment, a two-key switch is simply indispensable, because not always there is a free section of wall in order to put several devices side by side.
2. Can connect any two groups of lighting. The cable of both groups can come from one lighting fixture or from different fixtures, such as a floor lamp and a chandelier.
3. In addition to the single switch, it is also available in both classic and loop-through versions, which is useful when there is a long corridor that requires the ability to turn on and off the light at different ends of the corridor.
4. It is available in a waterproof as well as IP-protected version, which is advantageous when placed outdoors, for example on the porch of a private house. One lighting group it controls is responsible for e.g. the light above the front door and the second group for the outdoor lighting in the garden.
5. Although a two-button switch is slightly more expensive than a single switch, its installation is more advantageous because there is no need to buy two devices and pay for double installation.

Design of a switch with two buttons

Two-way switch differs only in one thing - to the terminals are connected two outgoing cables to the lights instead of one, and the phase from the junction box comes to the contact one, as in the case of a single-way switch.

This process is considered simple because it only requires pliers to remove the rubber braid from the wire, that is, thereby stripping it for further manipulation. In order to determine which group of lights will be turned on from each cable, and not to confuse the composition of the bulbs in one combination, the box with the keys should be installed in the operating position only after the temporary supply voltage to the two-way switch and test its performance.

Wiring diagram for two light bulbs

The wiring diagram of the two-way switch is extremely simple and can be done not only by a professional, but also by anyone, provided that the safety requirements and minimum tools and supplies are observed. The phase conductor from the power supply switchboard through the junction box goes to the terminals on the switch.

Inside the device itself, there are wires leading to the outgoing terminals that divide the power into two components, each of which forms a separate electrical circuit that closes or opens with one of the breaker keys. Two cables are connected to the outgoing terminals, each of which, by means of concealed or open laying in the wall or slab, fits to a lighting fixture or to two different fixtures.

This device must have in its design an internal terminal box for powering the different bulbs, to which the cables coming from the two-key apparatus are connected. Thus, in the example of a light fixture with two light bulbs, when properly connected, by pressing one button, the first light bulb will light up, the second one will light up. Both buttons pressed will close the circuit on the two wires and 2 bulbs will light up at once. The neutral cable goes directly from the junction box to the light fixture, providing grounding.

Installation of electrical wires

Installation of the two-key switch is carried out in the following steps:

1. The main rule of electrical installation work - all manipulation should be done only when the voltage is off to avoid the consequences in the event of a short circuit or human contact with bare wires. Always use screwdrivers, pliers, wire cutters and other tools with dielectric handles to prevent electric shock. It is recommended that you wear rubber gloves.
2. How to install a double light switch: first of all, you must choose the most comfortable place for the operation of the switch in the wall, then using a drill-cone to make a hole in the wall, sufficient for the device of a plastic box for the switch. Then, the wires are brought to the box with a reserve of length to make a reliable connection.
3. It is desirable to determine in advance the position of the terminals on the switch itself, so that the phase conductor and the PE conductor, which ensures the trouble-free operation of the device grounding, as well as the grounding points are in the right areas of the box. In order to be able to pull the cables after connecting the device, it is recommended to make all wiring in a conduit with a diameter at least twice the cross-section of the insulated cables. Particular attention should be paid to the grounding of the device.
4. How to connect a two-key light switch: cable outlets are stripped of insulation at the ends, and if the wire is stranded, its bare ends are stranded. It is recommended to use wires with copper cores that have minimal resistance. Remember to connect the PE conductor. Then connect the phase and neutral conductors using the built-in two-pin terminal block inside the switch.

• Careful attention should be paid to the wiring diagram, draw it in advance on paper or read the ready-made in the instructions for connecting and installing the switch, on the back of the device, if it is shown there. Try to avoid the formation of a long bare section after connecting the cables to the switch terminals, and if you find any, disconnect the wire and cut it so that when you reconnect the bare section will be as short as possible.
• It will be important to trace the entire route of the cable line from the fuse box to the junction box, then to the switch and to the light fixture. The cable along the entire length should have the same cross section, number and type of conductors. Otherwise, the section of wire with different characteristics should be replaced, as the consequences of its operation can be unpredictable. Sections of the circuit from connection to connection should preferably be made in a single piece of wire without connections along the length.
• Then apply voltage and carefully, observing safety precautions, test the switched-off device. When performing this phase of work, it is advisable to use protective goggles to prevent possible sparks in the eyes in the event of a short circuit, which can occur if the supply cables are incorrectly selected and the phase cable is connected in place of the earth cable. In this case, it is necessary to re-connect the voltage as soon as possible, if the circuit breaker in the switchboard has not tripped, and to re-wire the circuit by connecting the cables in the correct order.
• Before making connections by non-professionals, it is best to refer to special literature and study the features of the types of cores in the cable, because each of them has its own color according to the function performed. At the same time, the terminals are always arranged so that the incoming cable is inserted on one side of the switch, and the outgoing - on the opposite side.
• Press the switch with the cables into the box and flatten it with the special screws in the body of the device. If the wire runs are too long and get in the way, you should not bend them, as this can damage or even burn out the cables during operation. The best thing to do here is to disconnect the wires, trim them, re-insulate them and connect them. These screws are done in a concealed version, so it is necessary to remove the plastic lugs of the switch keys, which are held on the latches.
• If attempts to remove the key lugs do not give the desired result, it is better to study the installation instructions to prevent breakage of the device. After removing the key caps, you can clearly see the 2 screws located on the sides of the keys, which, when tightened, securely fix the unit to the wall. After wedging the unit and checking its immobility in the box, the key lugs are put back in place. The two-key switch is ready for use.

The first hours after the start of operation, in order to avoid unpleasant consequences, it is recommended to monitor the heating of the circuit breaker responsible for the connected lighting device, and if it overheats, to take measures to replace it.

It is important that connections are made in the right order not only inside the device, but also in the junction box and in the light fixture itself, because all the parts of the electrical circuit are inextricably linked to each other.

The connection of all cables should be made only after thoroughly stripping the ends of the insulation, the twisting of the two wires should be neat, even and tight and the insulation should cover all metal parts of the wires. It is unacceptable that bare wire ends can touch each other even over time. This will inevitably lead to a short circuit and the need to change the wire, which is problematic to do in the conditions of completed repair and finishing work.

Despite the relative ease of installation and connection of the switch, all work is better to perform with the involvement of a professional electrician, this ensures the safe and prolonged operation of the device. Do not use old, damaged, bent wires to connect. If even on a new wire is found damaged insulation, it is advisable not to use this section in the circuit.

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