Walk-throughs were created to conveniently control lighting in long corridors, on stairs, in walk-through rooms and in other places. They are installed between floors, when descending into the basement, near the doors of rooms with several entrances. While in your home, it is convenient to switch between utility rooms. Or control the lights on the porch and backyard. The checkpoint switch makes it possible to control lighting from different places, saving people from inconvenience. This also saves electricity.
A conventional switch contains a button for two positions and a pair of contacts. Wires are connected to them. In contrast, the built-in switch of the pass-through switch consists of three contacts: one common and two changeover contacts. Each of them is also connected to a wire. To control the lighting from several places, for example from two, a switching device with 4 contacts is required. In addition, there must be one lead to each one. So, you can control not only lighting, but also any other electrical appliances, although the installation of the circuit is complicated.
How does a one-rocker switch work?
The principle of operation is that one circuit is opened by a changeover contact, and the other is closed. The connection diagram of the pass-through switch is always on its reverse side. One of the contacts is common (1), and the other two are changeover contacts (2, 3). From two such devices located in different places, it is possible to assemble the simplest and most common scheme for controlling a luminaire from two different points.
The terminals 2 and 3 of the PV1 and PV2 switches that match the numbers are interconnected by wiring. Input part 1 from PV1 is connected to the phase, and PV2 is connected to the luminaire. The other end of the lamp is connected to the neutral power wire. How the loop-through switch circuit works is checked by turning it on. For a start, voltage is applied. In this case, the lamp sequentially lights up or goes out with independent switching of any of the switches. If one of them breaks, the circuit stops working. But at the same time, another line is being prepared for inclusion.
How to connect the simplest pass-through switch?
Before installation, draw a diagram of all connections.
(RK) is installed first. All wires will be collected and connected in it. Power is supplied here from the control panel. For this, a 3 x 1.5 mm three-core cable is laid. It is the most common for all wiring diagrams. Here, two conductors are supplying, and the third is for grounding electrical appliances. In addition, 2 socket boxes are installed in which the switches will be placed. Three-core cables are laid from each glass and from the lamp to the RK.
After all wires and cables are in place, connections are made. First, a wire of phase L is connected between the output of the machine and the input of PV1 (No. 1). Then the corresponding output contacts (2-2, 3-3) of the switches are connected to each other. Next, they are installed in a socket box. Two terminals of the cartridge to the input PV2 (No. 1) and to the blue neutral conductor from the control panel. If it is connected from its output contact, if single-pole - from the zero bus. The end of the grounding conductor is insulated. Or it is connected to the luminaire body if it is metal.
When all connections are completed, a light bulb is screwed into the socket. Then the circuit of the pass-through switch is checked by turning on the machine in the dashboard. The lamp may light up immediately. Or after switching on PV1 or PV2. You can extinguish it by pressing the key of any of the switches. Important! The switches have no fixed on and off positions.
Cross switch
Connecting loop-through switches at three locations requires additional installation of a cross-connect device. It consists of 2 single-key devices with internal jumpers, assembled in one housing.
A cross switch (PC) is installed between the two conventional ones. It only applies to them. Its distinctive feature is the presence of four terminals (2 inputs and 2 outputs). To control from four points, you need to add another such device to the circuit. The PCB should be connected to the changeover contacts of the pass-through switches in such a way that a working power supply circuit of the luminaire is created.
Complex contact groups require a lot of wires and connections. It is preferable to collect several simple circuits. They work reliably and are easy to use. Note! All main connections are made in junction boxes. No twists should be done on the lead wires.
Which model should you choose?
Which pass-through switch to use depends primarily on the type of wiring. For open, overhead models are selected. Under the hidden socket will be required. Suitable sizes should be chosen so that they can be connected together. It is important to install the normal and crossover switches with the same appearance. Devices are rotary, keyboard, lever, touch. Contacts are selected for the appropriate load. Switching should be easy. In this case, the devices must be securely fastened.
Installation of a three-point switching system
To do this, you need to perform the following actions:
- Draw a connection diagram.
- Mark and grind grooves and grooves for wiring and boxes.
- Install distribution parts. They are selected in large sizes so that 12 connections can be made inside.
- Install socket boxes.
- Lay the cable from the box to the connection points.
- Connect wires to switches and terminals in boxes. Mark the wires. Collect the circuit sequentially, checking the correctness of the connections.
- Set the switches to their places.
Connecting double-rocker switches
The device consists of 2 one-button independent switches. They are collected in one body. They work according to the same principle of flipping contacts. But the number of inputs is 2, and outputs - 4. The difference is that 2 switches are located at different points. Their keys work for different lights.
Installation of two-rocker switches for control from two locations
The sequence of actions should be as follows:
- A diagram is drawn up, without which it is difficult to make connections.
- Junction boxes and socket boxes are installed.
- 2 lighting groups are mounted.
- Three-core cables are laid based on the connection to the 6 contacts of each switch and to the luminaires.
- According to the drawn up diagram, the cable cores are connected in the junction box, to the lamp holders and to the switches.
The two-key pass-through switch can be replaced with a circuit of four one-key switches. But it will be irrational. As more junction boxes will be required and cable consumption will increase.
Control of two lighting systems from three locations
A two-key pass-through switch can be cross. It is installed in the kit. That is, it also includes two two-button limit switches if you want to control the lighting from three points. It will have 4 entrances and 4 exits.
Installation is carried out as follows:
- For mounting the circuit, a standard box with a diameter of 60 mm is not enough. Therefore, its size should be larger. Or you need to install 2-3 pieces in sequence. ordinary.
- There are 12 wire connections for the connection. To do this, you will need to lay 4 three-core cables. The cores should be labeled correctly here. 6 contacts are suitable for two limit switches, and 8 contacts for a cross.
- A phase is connected to PV1. Then you need to make the necessary connections. On the back side of the device, a two-key pass-through switch diagram is shown. It must match properly with external connections.
- PV2 is connected from luminaires.
- Four outputs of PV1 are connected to the inputs of the cross switch, and then its outputs are connected to 4 inputs of PV2.
Conclusion
The checkpoint switch is convenient. No extra walking up stairs and long corridors is required to turn a light on or off. Sometimes it is simply necessary. In addition, electricity is saved through fast switching times. It is important to choose the right devices and correctly install the electrical connections.