Wiring diagram for a two-key switch and step-by-step installation instructions

To optimize the process of controlling lighting fixtures in one or even two rooms, you can not use two different devices, but install one switch with two keys.

A connection diagram for a two-key switch will help you realize your plans, demonstrating the sequence of connecting electromechanical devices and artificial light sources with the wires connecting them to each other.

The article provides working diagrams for connecting the switch, lists tips for distributing wires, and also describes step-by-step instructions for installing a double switch. The information presented will be an excellent help to a home craftsman who plans to do all the work himself.

Why choose double switches

There are two popular circuit solutions that have long been successfully used when equipping electrical systems for private houses and apartments.

Option #1. Installation of a DV (two-button switch) in the bathroom area, if the toilet and bathroom are separated by a wall. Thus, one key controls the light bulb in the toilet, the second - in the bathroom.

Today, this option remains relevant and is actively used in standard housing, where the electrical wiring diagram has not fundamentally changed.

However, to expand control capabilities, instead of a two-key model, sometimes install a three-key switch, if the bathroom is supposed to control not one, but two lamps or groups of lamps.

Installation of DV instead of two separate devices is preferable from the point of view of saving materials for installation. In addition, it is more convenient to use one switch: by operating the keys, you can turn on and off the lights in different rooms with one movement of your hand

Option No. 2. The second common use of a two-key switch is to control a chandelier. The design of the lighting device makes it possible to connect light bulbs to two different keys, thereby adjusting the light level.

If one key controls 2 light bulbs, and the second – 4, then you can use three lighting modes: dim (2), light (4) and intense (6).

If bright lighting is required for reading, games or family dinner, then turn on all the light bulbs; to create a calm atmosphere for evening relaxation, dim light from one lamp is enough

A large number of modern chandeliers, especially LED ones, are controlled from a remote control. Multi-colored multi-mode Chinese models are considered especially advanced in this direction. But the option with a switch is still more reliable - the remote control can fail, but electromechanics rarely fail.

With DV you can control not only one, but also two lighting fixtures (or groups) installed in the same room. For example, if you connect a chandelier and a pair of sconces to different keys.

So, the two-key functions are very useful:

• control of multiple light sources;
• segment control of one but multi-track device (chandelier);
• the ability to adjust the degree of illumination in the room;
• saving of installation elements.

If you appreciate the capabilities of a two-key model and want to replace your old single-key model with it, you will have to change the connection diagram and, most likely, you will need to start with the wiring.

Connection diagrams for dual models

Before starting installation, it is necessary to divide the spotlights or chandelier bulbs that are planned to be connected to one DV into two groups. To create different lighting modes, they must be unequal (for example, 2 + 6 or 1 + 2).

More than two groups cannot be connected to one two-key switch; for a similar purpose, a three-key switch or separate electromechanical devices are used.

Using the simplest connection diagram, you can correctly distribute the wires. But first you need to study the color and alphanumeric designations, so that in the future it will be easier to “communicate” with the diagrams (+)

Mandatory elements of any DV connection diagram include the electrical device itself, the junction box and circuit breaker, which is installed on the electrical panel.

You will also need new wires, if the old ones do not meet modern standards, aluminum wiring remains in houses built in the mid-20th century.

One of the differences in connection diagrams concerns grounding systems. In older buildings, an outdated TN-C system is used.

Its difference is that the neutral and grounding conductors are connected in one PEN wire, thus, only two wires pass from the machine to the apartment instead of three. With a TN-C grounding system, the connection diagram looks like this.

Two wires are supplied from the electrical panel: blue (zero) and red (phase). In the distribution box, the phase goes to the red wire of the switch, where it is mounted in a common terminal, and the zero is immediately transferred to the light bulbs of the lighting fixture (one or more) (+)

If you need to connect a chandelier with several arms in a TN-C system, then the diagram looks like this.

This load distribution increases the number of wires in the distribution box: 2 from the machine, 3 from the switch and 3 from the chandelier, that is, a total of 8 wires (+)

However, the diagram changes fundamentally if you should connect not a chandelier, where all the lamps are concentrated in one place, but connect two light bulbs. Each lighting fixture requires a separate wire.

The working zero from the panel is divided into two groups of lamps, the phase still goes to the switch.From the switch, two phase wires are spread across both groups of light bulbs (+)

The modern TN-S grounding system does not require combining the ground with zero, so three standard conductors are laid from the panel.

The distribution of wires remains the same, but in the distribution box there is an increase in the number of connections, since the ground along with the zero is sent to the groups of lamps (+)

After determining the type of grounding system, all that remains is to select a suitable diagram and transfer it to the circuit breaker installation drawing, while specifying the installation locations of all participating devices.

When planning, we remember that the installation height of electrical installations for private use according to the PUE is from 0.8 m to 1.7 m, the distance to the gas pipe is at least 0.6 m, to the door frame is at least 0.15-0.20 m.

Step-by-step guide for installing DV

Before starting work, you should review the safety rules, purchase all the necessary devices and wires, and also prepare tools for installing devices and connecting wires.

You will need a wall chaser, a drill and a hammer drill if there is a need to install new wiring. Work gloves, protective clothing and goggles (mask) will not be superfluous when performing “dirty” work.

Installation of a protective device in an electrical panel

There is a possibility that a separate machine for one lighting group is already installed on the panel. But this is only possible if the house is new or has recently undergone major renovations. Previously, it was not customary to combine socket and lighting groups into separate circuits.

Separate lighting lines for rooms provide more options when installing new lamps or during renovation work: you can completely turn off the lights in one room without affecting the rest of the rooms

We strongly recommend for work on installation of the machine Call a qualified electrician, since independent manipulation of the protective equipment in the panel is prohibited.

All work subsequently related to electrical wiring must begin precisely from the general apartment electrical panel or cabinet, in particular, by turning off the circuit breaker of the circuit of interest (in our case, the lighting circuit).

Wiring options: hidden and external

In city apartments and modern cottages, hidden wiring is used, since it provides more opportunities for finishing, and is also safely hidden behind a layer of insulation in the wall.

In wooden houses they sell open wiring type, because laying wires inside logs is difficult and expensive - each cable must be placed inside a metal pipe.

For outdoor use, they produce wires in a special braid and accessories - ceramic rollers. Particularly popular are retro-style collections with rotary switches and twisted wires.

To organize an electrical network in an ordinary apartment, you need to make grooves in the walls in all distribution boxes, sockets and switches.

The grooves, according to the PUE, must run strictly horizontally (at a height of at least 2 m from the floor) or vertically.

At the same stage installing a junction box and a socket box, fixed with plaster. Grilling is the most time-consuming, labor-intensive and difficult stage.

After it, cleaning of the room is mandatory: you need to take out the trash, vacuum and wash the floor. Dust particles should not get into the junction box or inside the switch mechanism, that is, into the connection points of the wires.

Connecting wires in the distribution box

The distribution box is installed directly above the switch or in another place convenient for maintenance. It cannot be hidden under the cladding on the wall, as intervention may be required at any time.

The photo shows how to twist wires. This is the simplest, but not the safest method of connecting wires. Now there are more advanced methods, for example, using terminal blocks - convenient self-clamping devices. Soldering and welding are used extremely rarely.

Connecting and installing the switch

To independently connect and install a two-key switch, you will need screwdrivers, pliers, round nose pliers, a knife, wire cutters, and a level.

It is better to protect your hands with gloves for electrical work with a protective insulating layer. In addition, an indicator screwdriver or tester will be useful.

It was a kind of preparatory stage. After core stripping You can start connecting the wires to the switch.

The switch models and wires may be different, but the connection diagram remains the same.The connection in the distribution box can only differ in the addition of ground from the incoming power and the same ground wires from the lamps.

As you can see, there is a lot of work involved in installing a DV, and even if you just need to replace and reconnect the device, you can save money by doing everything yourself. Calling an electrician will cost from 200 to 500 rubles (the cost of replacing the switch only).

Compliance with safety regulations

Electric shock can result in irreversible consequences, so before each procedure for installing a switch or socket, you should follow a number of simple rules:

• the first step should always be to turn off the power at the electrical panel - circuit breakers are installed for protection;
• It should become a habit to regularly check the voltage in the network using a tester or indicator;
• You should use only serviceable tools with insulated handles and high-quality, unworn materials;
• Clothing and shoes should be comfortable and not create discomfort during work.

When working with a wall chaser, circular saw, chipper, hammer drill or drill, it is advisable to additionally use a protective mask and respirator.

Entry into the work area must be prohibited for unauthorized persons. If children or animals live in the apartment, it is better to leave them in another room for a while under the supervision of adults or send them to visit.

Conclusions and useful video on the topic

From the video materials presented below, you can learn how to independently connect a two-button light switch, how to correctly connect the wires and install electrical devices.

How to connect wires with terminals:

Installation of a double block “switch + socket”:

How the chandelier is connected to the Far East:

Living in a modern home is impossible without the use of electrical appliances and devices, so the skills of “communicating” with electricity can come in handy at any time.

Having learned the theory and practiced a little at home, you can easily change a switch, install an outlet, or divide your home electrical network into several easy-to-maintain circuits.

Do you have personal experience connecting a two-key switch? Do you want to share your accumulated knowledge or ask questions on the topic? Please leave comments and participate in discussions - the feedback form is located below.