Two-key switches are used, if necessary, to control two electric lighting devices simultaneously from one point. They also help to adjust the brightness of the light in the simplest way. Agree, connecting a light switch with two keys creates additional convenience.
We suggest that you familiarize yourself with the detailed installation process and installation of a double switch. Here you will find interesting information about the device design features of the light control. With our help, you can easily carry out installation.
We thoroughly described the briefing with visual illustrations, photo selections, wiring diagrams and a video guide.
Internal device breaker
The internal device of a two-phase switch differs from a single-phase switch by the presence of two output terminals instead of one.
More specifically, it consists of the following elements:
- mechanism and decorative panel;
- one input terminal;
- two output terminals;
- two keys.
Terminals are special clamping mechanisms. To connect the wire, it is enough to strip it, insert it into the terminal strip and tighten it with the screw. The input or common terminal is located primarily separately and is labeled L.
On the opposite side are two output terminals. They can be designated as L1, L2 or 1,2. Some models may have screw terminals instead of a terminal block. It is undesirable to use them, since the fastening may gradually weaken and it will have to be tightened.
The main difference between a two-key switch and a single-key counterpart is that it controls the pair of lighting fixtures
Install the device so that when it is turned on, press the upper half of the key. You can determine the top and bottom of an element using an indicator - a special screwdriver that works to close.
To do this, take a nail or a piece of wire and touch it to one contact, apply an indicator to the other, holding the thumb on top.
The device of the switch with two keys is slightly different from the one-key. The main components of the device: mechanism, keys and decorative body
If the light inside does not light, then the switch contacts are open. When the keys are on, it should light up. It remains to mark the top of the element.
Step-by-step process description
In addition to standard models, a two-key switch can be additionally equipped with a backlight, indicator. The backlight helps to determine it in the dark, and a glowing indicator will make it clear that the electrical network is working and is closed. They also produce models with shockproof and moisture proof housings. They can be installed in a bathhouse, bathroom or on the street.
There are also walk-through switches. They have almost the same design, with the exception of an additional terminal. Such devices are connected to one or a group of fixtures and allow you to control lighting from opposite ends of the room. For example, going into the bedroom, you can turn on the light, and going to bed, turn it off near the bed.
In practice, wiring accessories with one caliper and two keys or two single-key modules connected by a jumper can be used as a two-key device for controlling a lighting device. The difference in their installation is represented by the following photo selection:
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Two-gang switch mechanism
Modular two-key switch
Preparing wires for connection in the installation box
Connecting the two-key point mechanism
Jumper for connecting two modules
Connection of two separate modules with a strap
Connection of integrated modules to wiring
Installation of both options in the socket
# 1: Features of choosing a place to install
There are no standards for the placement of the device by law. Their installation implies convenient use for adults and children.
And if earlier it was common practice to place the device at a height of about 2 m, now the switch is often located at the level of the lowered hand of an adult. Thus, the element becomes available to almost all residents of the house.
It’s better to place the switch so that it is accessible to everyone except the smallest
The only place where the placement of the switch can have any restrictions is a bathroom or a bathhouse. Here you need to consider the placement of the washbasin and the open shower. When using the device, it must not fall under water drops.
# 2: Preparing for installation
Whatever electrical work you have to do, the first thing that is important to do is turn off the power to the network. Not for a second should we forget that electricity is dangerous. In addition to the effects of current, poorly wired electrical wiring can cause damage to electrical appliances or a fire in the house.
Rules of conduct when working with electric networks:
- be sure to disconnect the network;
- Do not touch connected devices with wet hands;
- Do not use metal brackets to secure the wiring;
- Do not overload the electric network;
- it is better to replace the damaged wire with a new one, and not repair it;
- work can only be done with a tool with insulated handles;
When working with electricity, do not touch water or gas metal pipes.
Getting started with an independent connection, you must:
- Take safety precautions
- familiarize yourself with the laws of wire marking;
- Check the network for labeling.
It is unlikely that any landlord will want to invite an electrician to replace and connect a switch. In addition, to perform this task, there is no need for complex instruments and tools.
To install you will need:
- mounting knife;
- insulating tape;
- hammer and chisel;
- pliers;
- indicator screwdriver, as well as curly and straight.
If the installation has to be carried out in a new place, and the house has hidden wiring, a drill with a “crown” nozzle or a perforator may come in handy.
Not a single electric installation work without a screwdriver indicator
# 3: Definition of electrical wires by color marking
Without knowledge and compliance with the marking, installation is absolutely impossible. It is used to create a safe environment and reduce time spent on work.
Correct labeling from the manufacturer will help to avoid problems with the identification of conductors.
The following notation is used to form the correct compounds:
- zero - always and without exception, blue;
- protection is also strictly the same color - yellow-green;
- phase - is predominantly brown or red.
These are just the basic combinations. In addition, alphanumeric marking is used to avoid confusion in identification.
If during the work it became clear that there are no visual signs, then it is necessary to independently mark the wiring using a multi-colored heat shrink tube or color insulation.
# 4: Identification of conductors with a multimeter
Blindly trust marking is not worth it. These designations have repeatedly changed their standards. Therefore, getting down to business, it is necessary to additionally check the nature of the conductors. To do this, use an indicator screwdriver and a multimeter.
If a single-phase electric network without a grounding system is carried out in the building, then an indicator will help to determine the phase or zero. Having disconnected the electric power, they clean the conductors and remove them so that they do not touch each other.
Turning on the power supply, bring a screwdriver to the wires. The light in the indicator will flash, when you touch the phase conductor, and from touching zero it will not light up.
Multimeter - a multifunctional control and measuring device that performs the work of at least three control devices: voltmeter, ohmmeter and ammeter
To analyze a network in which there is a third, protective conductor, use a multimeter. Setting the range for alternating current to a value of more than 220 volts, bring one tentacle to the phase, the other is fixed on any of the conductors. Upon contact with a neutral wire, the device will detect a voltage within 220 volts, with a protective one a little lower.
# 5: Removing an old electrical switch
To have access to the fasteners, you need to remove the keys and the decorative panel. To do this, use a screwdriver or a thin knife to pry the first key and carefully remove it. So do the second. Next, remove the decorative cover. In some models they are unscrewed.
The basic safety rule when working with electrical wiring and wiring devices is to disconnect the supply voltage for the period of work
Then the mechanism itself is taken out - it can be fastened with clamping feet or screws. Disconnect the conductors and, if necessary, dismantle the old socket.
The process of dismantling is clearly demonstrated in the photo gallery:
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Step 1: Disconnect the switch keys one at a time
Stage 2: Removing the locking element from the frame
Stage 3: Access to the frame for dismantling
Stage 4: Removing the switch block from the socket
# 6: Installation of elements with closed and open wiring
The installation of switches in newly built dwellings boils down to connecting the element to a previously conducted electrical network. In the old house, in which the old wiring already requires replacement, you have to make new shtabs and lay the cable.
And with open placement of electrical wiring, each cable is brought to the switch in insulating corrugated pipes, cable channels.
The subsequent selection of the circuit breaker model and the method of its installation depend on the method of laying the wires in the house. A device that is suitable for open wiring consists of a flat socket, an internal mechanism, an insulating decorative cover. The structure does not hide in the recess of the wall, but completely protrudes above the surface.
The device of switches for open and closed wiring differs only in the shape of the socket. For overhead devices, it is a thick plate of dielectric material
Installation begins with the installation of a sock - a flat bottom. Carry it out using suitable fasteners. For different wall surfaces, screws or dowels, screws, screws can be used.
Further, after connecting the wires, the mechanism of the switch is fixed, a decorative insulating cover is put on. In it, the manufacturer has already thought out a hole for supplying a conductor. The lid itself is put on, hiding the mechanism, and secured with latches.
To install a double switch in rooms with hidden wiring, use a socket box (mounting boxes) in the form of a small bowl. A hole is cut out in the wall or a small indentation of the appropriate size is made.
Clamps help to fix the mounting box in the wall reliably: when tightening the screw they slightly spread out and abut against the wall surface
During installation, make sure that the device locks smoothly, without distortions. Podrozetniki can be installed side by side - any required number - and fixed with plaster mixtures. Then, towards the socket, hollows are hollowed out with a depth sufficient to lay the wire.
Podrozetniki have special mounts that help them cling to their "neighbors"
# 7: Options for connecting electrical wires
The weakest links in the electrical circuit are the junction points of the wires. Not surprisingly, most malfunctions occur there.
The simplest in its own way, the method of connecting the wires with twists with additional fixation with electrical tape can not be called reliable. With poor performance, this is the most common cause of open circuit (+)
When connecting a switch, there is no need to consider all connection methods, here are the most basic ones:
- Manual twist - A very common method that requires subsequent isolation.
- Terminal block - It is widely used as a connecting link. It consists of copper clips clad in a plastic case.
- Soldering - Although it helps to create high-quality adhesion, the complexity of the process does not contribute to its popularity.
It should be said about the heat shrink tube, which perfectly helps isolate the joints and even strengthens them a little.
The heat shrink tube is tightly compressed around the wire when heated, creating reliable protection
# 8: Connection diagram and step-by-step actions
With the old system of conducting electrical networks, power is supplied to the house from the electrical panel via a two-wire cable. The ground loop is located on the transformer to which the neutral conductor is connected.
Despite its simplicity, this method has a significant drawback - a low level of security.
In the two-gang switch, the phase is connected with one wire, and each lamp is connected to a separate terminal
In the working case of the switch, one of the phase conductors of a three-core cable is connected to a common terminal strip (L). To do this, lead the wire into the terminal hole and tighten the screw. Two other phase electrical wires are connected to separate contacts, and then lead to the mounting box and connected to the phases of the luminaires.
When connecting a multi-tube chandelier to a two-gang switch, the lamps are divided into two groups
The wiring connection must be in a junction box. It hides sloppy weaves from sight and serves as an insulator.
To properly connect the electrical wires, you must do the following:
- Conductors coming from the fixtures and the two-phase switch, as well as the power supply cable, are put into a box, and the insulation coating is removed from the 2-3 cm section.
- Connect the phases of the main power cable and the switch.
- The incoming neutral wire is connected to the neutral wires of the fixtures.
- The phases extending from the switch are alternately connected to the phase conductors coming from the lighting devices.
Only a phase wire is led to the switch. It is strictly forbidden to connect it to a neutral wire. Otherwise, the ordinary replacement of a light bulb can be a dangerous procedure.
Any wire is better to fail with a margin, laying the excess behind the structure. It is not permissible to leave open wires, even inside the elements. All exposed areas must be carefully insulated. Do it better with textile tape.
You can familiarize with common schemes for connecting a double switch in a popular article on our site.
Connection example from a nearby outlet
Consider the option of connecting a control device for two lamps according to the scheme below:
Scheme for connecting a switch that controls two lamps from a nearby outlet
The location near the outlet and the switch is a common situation for small domestic apartments. Let's figure out how to connect a double switch in this case:
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Step 1: Prepare the power and lighting point
Step 2: Connecting the Outlet Mechanism
Step 3: Install the outlet in the installation box
Step 4: Securing the working part of the outlet
Step 5: Connect the zeros of the switch in the socket
Step 6: Connect the phase conductors to the breaker block
Step 7: Install the frame for the power outlet and electrical point
Step 8: Attaching the Switch Keys and Testing
Installing a two-phase breaker
To control several lighting fixtures from different ends of the room, use a walk-through switch with two keys. It is similar in internal design to two single-key walk-throughs, combined in a common decorative case. It contains two groups of terminals that open the current supply from one pair of electrical wires to another.
When making a loop-through connection, it is important not to mix the pairs of conductors so that both switches close the contacts of one of the two electrical circuits
How to install:
- The phase conductor from the mounting box is laid to the terminals 1 and 2 (right), which are interconnected according to the scheme.
- Four phases are already leaving the switch, which lead to the box, and then to the second switch.
- Two phases depart from switch No. 2 (without intersecting). They lead to the box, where they are connected to two independent conductors leading to the lamps.
Carrying out the installation, you can first carry out one pair of wires, and then the second, so as not to confuse them, otherwise the circuit will not work.
Connection to the power supply system
It is possible to determine that the electrical wiring is carried out according to the new system through the laid cable. It will be three-core with single-phase power or five-core with three-phase power. One of the single-phase supply wires will be the phase marked in brown or red, the other is neutral (zero) marked in blue, and the third will be the protective conductor marked in yellow-green.
To facilitate identification, use alphanumeric designations:
- A, B, C - phase;
- N is neutral or zero;
- PE - protective.
The difference between this connection scheme is an additional protective conductor PE, which is led directly to the luminaires.
The wiring diagram for TN-S wiring accessories involves connecting to a grounding system
After attaching the wires to the working mechanism, they are drawn closer to the case, and then installed in the socket. Fasten to the mounting box using clamping feet or bolts. Put on a decorative case and keys.
Before assembling the entire structure, turn on the light and make sure that the lighting system is working
You can watch the available video on installing a simple electrical circuit here:
When installing the electrical network or its elements, it is necessary to correctly follow the above instructions. If there are doubts about how to properly connect the light switch with two keys to the network, it is better to contact a professional.
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