Pass-through switches (switches) were created for convenient lighting control in long corridors, on stairs, in walk-through rooms and in other places. They are installed between floors, when going down to the basement, near the doors of rooms that have several entrances. Being in your home, it is convenient to switch the light in the garage, utility rooms. Or control the lanterns on the porch and backyard. The pass switch makes it possible to control lighting from different places, saving people from inconvenience. It also saves electricity.
A conventional switch contains a two-position key 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 by wire. To control lighting fromseveral places, for example from two, a 4-pin switching device is required. In addition, there must be leads to each one by one wire. So, you can control not only lighting, but also any other electrical appliances, although the installation of the circuit is more complicated.
How does a one-button switch work?
The principle of operation is that a changeover contact opens one circuit, and at the same time another closes. The connection diagram of the pass 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, you can assemble the simplest and most common scheme for controlling a lamp from two different points.
The terminals 2 and 3 of the switches PV1 and PV2 that match in numbers are interconnected by wiring. The input part 1 from PV1 is connected to the phase, and PV2 - to the lamp. The other end of the lamp is connected to the neutral power wire. How the pass switch circuit works is tested by turning it on. To begin with, voltage is applied. In this case, the lamp sequentially lights up or goes out when any of the switches is switched independently. If the circuit of one of them breaks, the circuit stops working. But at the same time, another line is getting ready to turn on.
How to connect a simple pass switch?
Before installation, draw a diagram of all connections.
The junction box (JB) is installed first. It will collect and connect all the wires. Power is supplied here from the control panel. For this, a three-core cable 3 x 1.5 mm is laid. It is most common for all connection schemes. Here, two cores are supply, and the third is for grounding electrical appliances. In addition, 2 sockets are installed in which the switches will be placed. Three-core cables are laid from each glass and from the lamp to the RC.
After all the wires and cables are in place, connections are made. First, the 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 the socket. Two lamp holder terminals are connected to the PV2 input (No. 1) and to the blue neutral wire from the control panel. If the machine is bipolar, it is supplied from its output contact, if single-pole - from the zero bus. The end of the ground wire is insulated. Or connected to the lamp body if it is metal.
When all connections are completed, a light bulb is screwed into the socket. Then the circuit of the through switch is checked by turning on the machine in the shield. The lamp may light up immediately. Or after turning on PV1 or PV2. You can turn it off by pressing any of the switches. Important! There are no fixed "on" and "off" positions in the switches.
Cross switch
Three-way feed-through switches require additional installation of a cross-connect device. It consists of 2 single-key devices with internal jumpers assembled in one case.
Cross switch (PP) is installed between two conventional switches. It only applies to them. Its distinguishing feature is the presence of four terminals (2 inputs and 2 outputs). To control from four points, you need to add one more such device to the circuit. Connect the PCB to the changeover contacts of the feed-through switches in such a way that a working power supply circuit for the lamp is created.
Complex contact sets 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 can be made on the lead wires.
Which model to choose?
Which pass switch to use primarily depends on the type of wiring. Overhead models are selected for the open. Under the hidden socket boxes will be required. Appropriate sizes should be chosen so that they can be connected to each other. It is important to install the normal and cross switches with the same appearance. Devices are rotary, keyboard, lever, touch. Contacts are selected for the appropriate load. Switching should be easy. Devices are required to reliablyfasten.
Installation of the three-point switching system
To do this, you must do the following:
- Draw a wiring diagram.
- Mark and drill strobes and recesses for wiring and boxes.
- Install distribution parts. They are chosen in large sizes so that 12 connections can be made inside.
- Install sockets.
- Lay the cable from the shield to the connection points.
- Connect wires to switches and terminals in boxes. Mark wires. Assemble the circuit sequentially, checking the correctness of the connections.
- Set switches in place.
Connection of double-gang switches
The device consists of 2 single-key independent switches. They are collected in one building. They work on the same principle of throwing contacts. But at the same time, the number of inputs is 2, and the outputs are 4. The difference lies in the fact that 2 switches are located at different points. Their keys work for different lamps.
Installation of two-gang switches for control from two places
The sequence of actions should be:
- A diagram is being drawn up, without which it is difficult to make connections.
- Distribution boxes and sockets are being installed.
- 2 lighting groups are mounted.
- Three-core cables are laid for connection to 6 contacts of each switch and to fixtures.
- According to the drawn up scheme, the cable cores are connected tojunction box, lamp sockets and switches.
The double-gang switch can be replaced by a circuit of four single-gang switches. But it will be irrational. Because more junction boxes will be required and cable consumption will increase.
Control two lighting systems from three locations
Two-key switch through passage is cross. It is installed as a kit. That is, it also includes two two-key limit switches, if you want to control the lighting from three points. It will have 4 inputs and 4 outputs.
Installation is as follows:
- A standard box with a diameter of 60 mm is not enough for mounting the circuit. Therefore, its size should be larger. Or you need to sequentially install 2-3 pcs. ordinary.
- There are 12 wire connections for connection. This will require laying 4 three-core cables. Here it is necessary to correctly mark the cores. Two limit switches are suitable for 6 contacts, and for the cross - 8.
- Phase is connected to PV1. After you need to make the necessary connections. On the back of the device is a diagram of a two-key pass-through switch. It must match correctly with the external connections.
- PV2 is connected from fixtures.
- Four PV1 outputs are connected to the inputs of the cross switch, and then its outputs are connected to 4 PV2 inputs.
Conclusion
The pass switch is convenient. No extra walking up stairs and long corridors is required to turn a light bulb on or off. Sometimes it is simply necessary. In addition, energy is saved due to fast switching. It is important to choose the right devices and correctly install the electrical connections.
