For the convenience of controlling lighting and electrical appliances in large apartments, a pass-through switch is often used. Such devices are designed to provide the most comfortable operation of electricity consumers. In private apartments, their installation is used to control lighting devices on stairs, in corridors, bedrooms and other places where it may not be enough to install one device for the convenience of turning on the light in the room. This is often associated, for example, with the need to return to the opposite end of the corridor or get out of bed in order to turn on or off the light in the room.
Devices can serve as an alternative to such switches, controlled remotely with a remote control. However, their use is associated with a number of significant disadvantages, such as the need to periodically replace the remote control battery, as well as its possible loss.
To figure out how to connect a pass-through switch, you must first understand its internal structure and principle of operation.
Device design
The classification of light switches through passage directly depends on their design and functional purpose. By the number of independent switched electrical circuits, such devices are divided into single-key, two-key and three-key.
The simplest pass-through switch is a product that has three terminals for connecting wires, one of which is an input and two are outputs. The working contact of this switching device has only two positions, in one of them one line is closed, and in the other - the second. When the switch key is pressed, its contact group changes its position, thus opening one of the circuits and at the same time closing the second. This allows you to control the lighting simultaneously from two places.
Some models of such devices also have an intermediate contact position in which both of them are in the open position. The three-position switch belongs to a separate group of products with its own specific tasks and is rarely used in lighting circuits.
Another type of device that is designed to control electrical appliances from three or more places are cross switches.
Their design is different in that it contains a pair of interconnected contacts, the switching of which occurs simultaneously when a key is pressed. Such products can be made in three- and two-key versions. They are designed, respectively, to control the work of three or two groups of consumers.
Wiring diagrams
Lighting control from two, three or more places can be implemented according to a scheme using a pass-through switch, the connection of which is a fairly simple task.
In order to provide lighting control from two places, it is necessary to use a switching circuit, which includes two such products. Changing the position of the contacts of any of them leads to turning on or off the voltage on the lighting device. You can implement this circuit using the following connection of the elements of the electrical circuit.
As can be seen from the figure, the circuit for connecting the feed-through switches has some differences from the similar circuit for conventional switching devices. Most of all, it resembles the connection of a conventional double switch, however, there is a fundamental difference, which consists in the fact that in any position of the closing contacts, one of the two switched circuits is closed. Thus, two switches form a single lighting control system.
This technical solution allows you to apply voltage to the input of the consumer of electrical energy by changing the position of the contacts of any two switching devices.
The pass switch, the diagram of which is shown in the figure, allows you to control the lighting from two places. In practice, situations often arise that require the use of more complex devices that provide the ability to control the operation of an electrical network from three or more places.
To implement various schemes for controlling consumers of electricity, double or triple, as well as cross switches, can be used.
Connection order
Installing a walk-through switch is not too difficult. This is almost as easy to do as installing conventional switching devices.
The sequence of preparatory actions that must be done during its installation is the same as when installing any elements electrical wiring:
- As a rule, the laying of wires for the installation of any wiring elements is carried out during large-scale repair work, including laying cables in strobes, as well as preparing and installing mounting boxes for switches. To ensure a reliable connection of the device contacts to the wires, they must protrude beyond the edge of the box by at least 60 mm.
- If the wiring and installation of the installation boxes have already been carried out, then they should be prepared for the installation of switches. To do this, you need to release the ends of all wires (their number depends on the design of the switch) from the insulation by 50-150 cm.
- The first thing to do is to turn off the voltage on the electrical wiring elements using circuit breakerinstalled at the entrance to the apartment. Before proceeding with any actions with electrical wiring elements, it is necessary to make sure that there is no voltage using an indicator screwdriver or a tester.
- The wires are connected to the terminals using the markings on the body of the product. In this case, the incoming wire is indicated by the letter L (L1 and L2 if the switch is two-key), and the outgoing wires are indicated by arrows. Sometimes a wiring diagram is applied to the back of the case. The order in which the wires are connected does not really matter, it can be done in any order.
- The working part of the switch is inserted into the box and fixed with sliding benches or clamps.
- A plastic frame is being installed on the front of the device.
- The key (or keys) is set.
- At the last stage, it is necessary to make a control inclusion of each device to make sure that the circuit is working.
Connection Features
The main features of connecting walk-through switches are:
- The number of wires required for their operation. It should be noted that a three-wire wire is suitable from the junction box to such a device, phase voltage is supplied to the switch through one of its three wires, and the other two are outgoing wires.
- Particular attention should be paid to the order in which the two switches shown in the diagram are connected to each other. A junction box must be used for this. However, in practice, it is often more expedient to lay a two-wire wire directly from one device to another, which allows significant savings. In this case, only one wire can come from the junction box to the switch instead of three.
In order to control lighting from three or more places with the ability to control different groups of lighting fixtures, you should use circuits that include two-button walk-through and cross switches.
The figure shows the connection diagram of one group of lighting devices, which can be controlled from five different points. The first and last element of the presented series connection is a feed-through switch. The number of cross switches that can be used in such a circuit is limited only by considerations of practical expediency and ease of use.
The cross switch device is quite simple. It has two pairs of contacts to which an incoming and outgoing two-wire wire is connected. When the key is pressed, the previously closed contacts are simultaneously opened and they are cross-connected with each other. This allows you to change the state of each of the two wires laid between the walk-through switches, without pressing a key on either of them.
Jumpers between the contacts of such a device, which are shown in the figure, are needed for a more visual demonstration of its operation. In practice, such a product in most cases has only 4 contacts, which greatly facilitates the process of connecting it.
To be able to control two groups of consumers at the same time, you must use two-gang switches. The principle of their operation does not differ from that already considered, however, the connection scheme is naturally more complex.
A two-gang pass-through switch can be considered as two single devices placed in one housing.
If it is necessary to control groups of consumers from three or more places, it is necessary to use two- or three-gang cross switches.
As can be seen from the figure, each two-key device has six terminals for connecting wires. They are located in such a way as to eliminate the double interpretation of the location of the contacts of each individual electrical circuit. And yet, you should pay attention to the color marking of the wires. According to generally accepted rules, the insulation of the grounding conductor is painted yellow-green, and the zero worker is blue. The phase conductor can be painted in any color, but most often black or brown insulation is used.
As for the installation method of the pass-through switch, then, like other electrical wiring devices, it can have an internal or external installation method. Each of them has its own advantages and disadvantages, however, in most cases, internal installation is used, as a more reliable, aesthetic and safe option.
Thus, the process of installing a pass-through switch seems to be a task that is quite within the power of any person. The main thing at the same time is to clearly present the connection diagram of lighting devices, as well as the place of the mounted device in it.
