Pass-through switch: connection diagram for 2 keys + tips for selection and connection

A modern two-key pass-through switch can increase the level of comfort when controlling lighting equipment in almost all premises, including residential, technical, industrial, etc. In addition, it is safe and, if used correctly, will help reduce energy consumption. Not a bad prospect, don’t you agree?

Are you thinking about installing a pass-through switch with 2 keys yourself, but don’t know where to start? We will help you understand this issue - in our article we will analyze in detail its features, the nuances of choice, as well as connection diagrams and the procedure for performing electrical installation work with your own hands. To make it easier for beginners to master the material presented, we have provided the publication with visual photos and step-by-step video installation instructions.

Design and tasks of a pass-through switch

Two-key pass-through switches are similar in appearance to conventional ones used to control groups of lamps, chandeliers, sconces and other lighting fixtures. But both one and the other are used to solve everyday problems of consumers.

Walk-through and traditional two-gang switches are used to control:

• two independent lamps/chandeliers;
• two groups of lamps on one lighting fixture.

But ordinary two-key switches make it possible to turn on/off lighting fixtures from one place, and walk-through ones from different places.Which is their main task and advantage.

This feature and the presence of two keys will make it possible not only to turn on the lamps at one point in a room and turn them off in another, but also to use only part of the light bulbs of the device.

If necessary, lighting fixtures in adjacent rooms and parts of the building can be brought into working condition. For example, illuminate not only the stairs, but also the basement to which it leads. This will eliminate the need to move by touch in dark rooms and will save electricity.

Technological two-key pass-through switches are successfully used in any premises. This statement is also true for small apartments, especially if there is zoning and a desire to optimally use the capabilities of existing lighting systems

In residential premises, such switches are used most often, since they are usually equipped with several independent lighting systems.

Using two-key switches can be beneficial even in a small room. For example, in a Khrushchev house with walk-through rooms or simply equipped with two lighting lines.

How are they different from single-key switches?

Electrical installation products for one key, both walk-through and conventional, allow you to control only one lamp or a single group of lamps. But the two-key analogue has two.

Installing any pass-through switches differs from replacing conventional ones. And the main difference is that the owners of the premises will have to make more important decisions. For example, determine the location and method of equipment installation. And this needs to be taken seriously to avoid mistakes.

As a result, both types of products can be used most effectively in different operating conditions.

Product design features

A pass-through two-key switch is structurally composed of 2 single-key analogues. And therefore it has 2 times more contacts for connecting wires.

So, if walk-through switches equipped with a single key have only 3 of them (and ordinary ones have 2), then two-key switches have 6:

• input - 2;
• weekends - 4.

To avoid installation errors, manufacturers often indicate the connection diagram or mark the inputs/outputs on the device body.

You can often hear that such a large number of contacts is needed to ensure that the switch operates on the “flip” principle. But this formulation does not entirely correspond to reality. Since switching off occurs when the contacts that are part of two-key switches and control one line are simply moved to different positions.

If the specified structural elements are returned to one position by switching the key, then the light bulbs will turn on.

That is, the keys do not have the usual fixed “on”/“off” positions that users are used to, like traditional switches. Although both types of equipment have controls that move in the same way.

The photo shows a two-key pass-through switch. Its main feature is a large number of inputs/outputs. In this case, they are marked with arrows by the manufacturer to reduce the likelihood of errors when connecting

A larger number of contacts requires the use of more wires to ensure the functionality of two-gang switches.If compared with single-key analogues, then they will need exactly 2 times more.

Preparatory work before connection

In almost all cases, when installing two-key electrical installation products, additional wiring and installation of additional equipment will be required. And all this, most likely, will have to be purchased.

So, at the preparation stage you will need:

• Two three-wire wires required length for each switch. It is important that its cross-section is at least 2.5 mm². It is also important that copper is used as the manufacturing material. We recommend that you read the rules choosing wires for home wiring.
• Junction box. It is needed because the cable from the pass-through switch, for safety reasons, cannot be laid directly to the lighting fixtures. It should be remembered that there will be many connections, so the volume of one standard box is unlikely to be enough. Therefore, even before starting work, you should think about purchasing paired products.
• Installation box, which is also called a socket box. Such devices are used to accommodate the pass-through switches themselves.

The wire is laid open or in a closed way. But in any case, before starting installation, the purchased electrical cable should be checked for functionality.

The photo shows a model of the lighting control system, which allows you to get an idea of ​​​​what should come out during the installation of two-key switches

When checking the cable, you first need to perform an external inspection, and then ring it using special equipment, for example, a multimeter.

If you ignore this rule, you can suffer significant losses. This is especially true for cases where the wire will be mounted into the wall.

If it is possible to ground the pass-through switch, then it should be used. This applies to cases where a PE bus is provided. It is usually available in new buildings.

When performing connection work, safety precautions must be observed. So, before starting the procedure, you should turn off the power to the room..

Connection diagram and order

Regardless of the brand and other features of two-key electrical installation products, a number of important rules will have to be followed during installation.

The picture shows a connection diagram for two-key pass-through switches. In this case, the Latin letter N is the international designation of the neutral wire (marked in blue). And the letter L marks the phase wire. On diagrams, and often in reality, it is indicated in orange

So, initially it is necessary to prepare a place for installing socket boxes and a distribution box. But this is not difficult, since all you need to do is install a core drill of the required diameter into the hammer drill. We recommend that you read the detailed instructions for installation of socket boxes.

It should be remembered that 2 wires consisting of 3 wires (in the form of ends 10-15 cm long) should come to the distribution box from each two-key pass-through type switch:

• To connect the keys of the first switch with the mains phase - for which in each case, terminals are used, which in electrics are designated by the symbols L1, L2.
• Connecting the keys of the second switch with the phase wire of the desired lamp or group of them - in this case, terminals are also used, which are designated by the abbreviation L1, L2.
• Connecting both used switches to each other - the remaining wires are connected in pairs. This procedure is carried out in a junction box. During this operation, it is necessary to connect the terminals of each key of one pass-through switch with similar terminals of the second.

We must not forget that the neutral wire of the supply wire must be connected to the neutral wire of the electrical appliance. If you plan to control a group of lamps, then the network zero is connected to all of their neutral conductors. We reviewed the best connectors for connecting wires in the article about self-clamping terminal blocks.

Correct connection is the key to the safe operation of switches and lamps, and it largely depends on the connectors. Therefore, it will be practical to use convenient and reliable WAGO terminal blocks. They are self-clamping and safe, so the influence of the human factor will be minimal

When performing electrical installation work, it is important not to get tangled with cables. This warning is relevant due to the presence of a large number of cores. They should be marked, especially in cases where the wires are the same color.

In addition, all operations should be performed sequentially, that is, without switching to another job before completing the one started.

Detailed instructions connecting a pass-through switch for 2 keys we gave in our other article.

How to make the right choice

When purchasing two-key pass-through switches, you should give preference to products from well-known manufacturers.

For example, in the post-Soviet space, as well as in Europe, the products of the popular German brand Legrand are popular.

It is worth paying attention to switches belonging to the Celiane and Velena series. The exclusive products of this manufacturer belong to the Exclusive Celiane line.

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In addition, the following companies are ranked among the leaders in the field:

• Wessen and its popular W 59 Frame switch series;
• Lezard;
• Makel.

There are various types of pass-through switches. But sensory ones are more popular among consumers.

Two-key switches can become part of the system "smart House". Since many manufacturers equip their products with motion sensors. As a result, the electronics will take care of turning off the lighting.

Conclusions and useful video on the topic

The first video will help you avoid mistakes and excessive spending when choosing and purchasing pass-through switches:

The following video shows in practice how to connect switches to a lighting system:

Two-key pass-through switches can make living more comfortable and safe. And also, if placed correctly, the equipment will help save energy. At the same time, there is no doubt about its quality - such switches are intended for long-term use.

Tell us about your personal experience in choosing two-key pass-through switches, places for their installation and operating features. Comments can be left in the special block located below.There you can also ask our experts and other site visitors any questions you have, take part in the discussion, and point out inaccuracies or errors identified while reading the article.