Two-Way Switch Wiring Diagram: The Best Way To Connect It

To optimize the control of lighting fixtures in one or even two rooms, you can install a single switch with two keys instead of using two different devices.

How to do this, a two-button switch connection diagram demonstrating the connection sequence of electromechanical devices and artificial light sources with connecting wires between them can help.

The article contains working diagrams of switch connection, lists tips on wire assignment as well as a description of the wiring. The information given will be a great help to the home handyman planning to do all the work himself.

To read:

  • Why choose the double push-button switches
  • Wiring Diagrams for Double models
  • Step-by-step guide for installing the DV
    • Installing the Safety Device in the Control Panel
    • Wiring variations: concealed and outdoor
    • Wire connection in the distribution box
    • Wiring and installation of the switch
  • Heeding safety rules
  • Conclusions and useful video on the subject

Why two push-button switches are chosen

There are two popular circuit solutions long and successfully used when equipping private homes and apartments with electrical systems.

Option 1. Installation of a two push-button switch in the bathroom area if the toilet and the bathroom are separated by a wall.

Today, this variant is still very much alive and in typical housing, where the wiring has not fundamentally changed.

But in order to increase the control possibilities the 3 push-button version is sometimes used instead of the 2 push-button version if more than one lamp or groups of lamps are to be controlled in the bathroom.

Two-way switch wiring diagram: the best way to connect it

The installation of the DV instead of the 2 separate devices is preferred from the viewpoint of saving installation materials. In addition it is more convenient to use one light switch: the keys can be used to turn the light on and off in different rooms with just one movement of the hand

Option 2. The second common use for a switch with two keys is to control a chandelier. The light fixture is designed in such a way that the light bulbs can be connected to 2 different keys in order to adjust the light level.

If one key controls 2 light bulbs and the other 4, then 3 lighting modes can be used: dim (2), bright (4) and intense (6).

Two-way switch wiring diagram: the best way to connect it

If you want bright light for reading, playing games or having dinner with the family, switch on all the lamps; to create a quiet atmosphere for an evening out, a dimmed light from a single lamp is enough

Many modern chandeliers, especially LED ones, are controlled by remote control. Especially advanced in this direction are considered multi-color multi-mode Chinese models. But the version with a switch is still more reliable - the remote can fail, and electromechanics rarely fails.

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

The functions of the push-button are very useful:

  • control several light sources;
  • segment control of one but multiple light sources;
  • the possibility to adjust the room light level;
  • saves the mounting elements.

If you have appreciated the possibilities of the 2 push-button version and you want to replace the old 1 push-button version, you will have to modify the wiring and you should probably start with the wiring.

Double models

We should divide the spot lights or chandelier bulbs that you want to connect to one DT into two groups before starting the installation. They must be unequal (e.g. 2 + 6 or 1 + 2) to create different lighting modes.

More than two groups cannot be connected to a single two-key switch, for this purpose use a three-key switch or separate electromechanical devices.

Two-way switch wiring diagram: the best way to connect it

Use the simplest wiring diagram, you can correctly distribute the wires. But beforehand it is necessary to study the color and alphanumeric designations in order to make it easier to \"communicate\" later on with the circuits (+)

A mandatory element of any wiring diagram for DV includes the electrical device itself, the junction box and the circuit breaker which is installed on the electrical panel.

Also new wires will be required if the old ones do not meet modern standards - houses built in the mid-20th century still have aluminum wiring.

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Hanging or internal two-key switch

Distribution box to connect wires

Auto lighting group protection device

Pipes for creating an electrical circuit

One of the differences in the wiring arrangements concerns the earthing systems. Older buildings use the old TN-C system.

The difference is that the neutral and earth conductor are connected in a single PEN conductor, so that only two conductors instead of three go from the fuse to the apartment. In the TN-C grounding system, the wiring diagram is as follows:

Two-way switch wiring diagram: the best way to connect it

Two wires, a blue (zero) and a red (phase), are fed from the starter panel. In the switchboard, the phase goes to the red wire of the switch, where it is connected to a common terminal and the zero is connected to the light bulbs of the light fixture (one or more) (+)

If a chandelier with several horns is to be connected in a TN-C system, the circuit is as follows.

Two-way switch wiring diagram: the best way to connect it

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

But the circuit changes fundamentally if you do not want to connect the chandelier where all lights are concentrated in one place, but connect two lamps. Each light fixture requires a separate wire.

Two-way switch wiring diagram: the best way to connect it

The operating zero from the switchboard is divided into two groups of fixtures, the phase still goes to the switch. From the switch, the two phase wires are distributed over both groups of lights (+)

The modern TN-S grounding system does not require the ground to ground connection, so three standard conductors are laid from the switchboard.

Two-way switch wiring diagram: the best way to connect it

The distribution of conductors remains the same but in the switchboard the number of connections increases because the earth together with the zero is sent to the lamp groups (+)

After knowing the type of earthing system, the suitable circuit is chosen and transferred to the switch installation drawing, checking the mounting positions of all devices involved.

When planning, remember that the height of installation of electrical installations of 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 jamb at least 0.15-0.20 m.

Step-by-step guide to installing the DV

Before starting work, you should repeat safety rules, acquire all necessary devices and wires, and prepare tools for installing appliances and connecting wires.

A chisel, drill and perforator are required if new wiring will be needed. Working gloves, protective clothing and goggles (mask) are not superfluous during \"dirty\" work.

Installation of a protective device in the electrical panel

It is possible that there is already a separate fuse for one lighting group on the panel. But this is only possible if the house is new or has recently undergone a major renovation. In the past it was not usual to combine the socket and light groups into separate circuits.

Two-way switch wiring diagram: the best way to connect it

Separate room lighting lines provide more possibilities during the installation of new fixtures or during renovation work: the light in one room can be switched off completely without affecting the other rooms

It is strongly recommended to have a qualified electrician install the breaker, as it is not possible to handle the safety equipment in the switchboard yourself.

All further work related to the wiring must start exactly from the general electrical switchboard or cabinet, in particular with the disconnection of the circuit breaker of interest (in our case, the lighting circuit).

Wiring options: concealed and outdoor

In urban apartments and modern cottages, concealed wiring is used because it gives more possibilities for finishing, moreover it is safely covered by insulation in the wall.

In wooden houses, the exposed type of wiring is used because placing wires inside the logs is complicated and expensive - each cable has to be placed inside a metal pipe.

Two-way switch wiring diagram: the best way to connect it

Wires for the outdoor version are made in special braids and fittings - ceramic rollers. Very popular are the retro style collections with rotary switches and stranded wires

To install a power supply in a normal apartment, grooves in the walls must be cut in all junction boxes, sockets and switches.

Routing must be horizontal (at least 2 metres above the floor) or vertical according to Electrical Code.

In this phase we put the junction box  and the socket, fixing it with plaster. Drilling is the longest, most time consuming and difficult stage.

After this stage it is compulsory to clean the room: it is necessary to remove the garbage, vacuum and wash the floor.

Wiring in the switch compartment

The distribution box should be installed directly above the switch or in a suitable place for maintenance. It must not be hidden under the wall cladding as intervention is required at any time.

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Which wires are brought into the box

Removing insulation and stripping wires

Wires ready to be connected

The simplest connection method is twisting wires

The photo shows, This picture shows how to make twisted wires. This is the simplest but not the safest method of connecting wires. There are now more advanced methods, for example, using terminal strips, which are handy self-clamping devices. Soldering and welding are very rare.

Wiring and installation of the switch

To connect and install a two push-button switch you need screwdrivers, pliers, round pliers, knife, wire cutters, level.

Perfect electric gloves with an insulating layer are best. A screwdriver or tester is also useful.

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Step 1 - preparing the recess for installation

Step 2 - Disassembly of the switch

Step 3 - trimming the wires

Step 4 - stripping the wires

This was a kind of preparatory step. After stripping the wires you can proceed to connect the wires to the switch.

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The common phase wire, which has a red or brown insulation, is fixed in the terminal block according to the diagram. On the reverse side there are indicators (e.g., L)

The standard switches use a screw-type connection. That is, after the wire is inserted into the terminal, it must be clamped by tightening the screw

The remaining two wires lead to the two lights or groups of lights. These wires are connected to the terminals marked by numbers or arrows

After making sure that the wires are fixed correctly, according to the chosen connection scheme, we insert the mechanism into the socket or simply fix it on the wall

It is necessary to align the device relative to the horizontal axis. To do this, the level is used and the position of the device is corrected with light movements

Usually the internal mechanism is fixed on a metal frame, which is screwed to the wall with 2-4 screws. Then the position is checked once again

At the last stage the decorative exterior of the plastic parts is set in place - the frame is clicked and the keys are inserted

The initial test should be made before inserting the mechanism in the wall. In the final step another test

Step 5 - connecting the correct phase

Step 6 - fixing contacts

Step 7 - connecting outgoing phases

Step 8 - assembly mechanism in place

Step 9 - Checking the horizontal position

Step 10 - attaching the switch

Step 11 - mounting the decorative part

Step 12 - testing the switch.

Models of switches and wire may vary, but the wiring remains the same. The connection in the distribution box may differ only in adding a ground wire from the incoming supply and the same ground wire from the light fixtures.

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


Even though electrocution can have serious consequences, you should follow some simple rules before each installation of a switch or socket:

  • The first step should always be to disconnect the power at the electric panel - for protection and install automatic machines;
  • It should become a habit to regularly check the voltage in the network with a tester or indicator;
  • only serviceable tools with insulated handles and quality, unworn materials should be used;
  • clothing and shoes should be comfortable and not create discomfort during work.

When working with a floor saw, circular saw, bailer, rotary hammer or drill it is advisable to additionally use a protective mask and respirator.

An outsider must not enter the work area. If there are children or pets in the apartment, it is better to temporarily leave them in another room under adult supervision or send them away.

Conclusions and useful videos on the subject

In the following videos you can learn how to connect the two-key light switch yourself, how to wire it properly and make electrical installations.

How to connect the wires with terminals:

Installing a double block \"switch + socket\":

How a chandelier is connected to a DV:

Living in a modern house is impossible without using electrical appliances and devices, so skills to \"communicate\" with electricity can come in handy at any time.

Learning the theory and gaining some practice at home allows you to change the light switch, install the socket or split the home electric circuit into manageable loops.

You have personal experience of the two push-button switch? Would you like to share your accumulated knowledge or ask questions about the topic? Please leave comments and participate in discussions - the feedback form is below.

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