Connecting pass-through switches. Connecting pass-through and crossover switches. We mount wires and installation elements of the circuit
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When performing work on the installation of 220V electrical lighting networks in domestic and industrial premises, there is often a need to control several lighting devices from one point. For these purposes, a switch with two keys is used. Devices of this design provide switching on and off of lighting devices with two or more lamps. Sometimes, the layout of the electrical wiring of the lighting network provides for the control of several groups of lamps or individual lamps on one lamp. A two-key one is also suitable for these purposes.
For proper operation of the double switch, it is necessary to connect it correctly. In this case, a certain sequence of actions should be followed to ensure personal safety and the safety of others. Recommendations for safe installation of two light bulbs are discussed below.
Preparatory work
Preparation for installation of electrical switching devices (in this case, switches) involves understanding their structure, purpose, design, operating principle and the availability of tools for their installation in domestic and industrial conditions.
The number of switched-on lighting devices is regulated by a switch that has an additional outgoing contact and a separate control button. It usually does not differ in size from single-key ones. This is done for the convenience of replacing them with each other. The main difference is their switching “stuffing”.
A device with two keys has a working part that includes three contacts. One of the contacts is incoming, and the other two are outgoing. Outgoing contacts have independent on/off control.
During installation, it is positioned so that the outgoing contacts are located at the top. This is due to generally accepted standards for the on/off position.
The phase wire coming from the junction box is connected to the terminal of the incoming contact. The phase wires of consumers are installed on the terminals of the outgoing contacts: individual lamps of one lamp, individual lamps, separate groups of lamps.
The neutral wire (working zero) to consumers comes out of the distribution box and does not pass through the switch.
According to their design, two-key models are divided into models for installation directly on the wall (for open wiring), and models for internal installation in the wall (for hidden wiring).
Connection diagram for a two-button switch for two light bulbs
To correctly connect to the electrical network, you should understand the electrical diagram of its installation.
A modern electrical network provides for the presence of a grounding conductor in the supply networks of all electrical consumers. There is no such conductor in the electrical wiring networks of Soviet-era houses. And in many private buildings it is not always available, especially in lighting networks. This can be explained by the relatively low electrical power of household lighting fixtures.
Therefore, it would be objective to consider the connection diagram of a two-key switch for wiring without a grounding conductor.
This diagram shows an example of connecting two lamps of one lamp, or two independent lamps. In this case, the phase wire comes to the input terminal of the switch and, through independent outgoing contacts, is sent to consumers by two separate wires.
For greater clarity, a diagram of the connection of two independent groups of lamps, or lamps connected in series, is shown.
When using such a scheme, the connection of the working part of the device does not change and is carried out similarly to the previous example.
What tools and materials will be needed to install a double switch?
To perform installation you will need the following tool. Considered for models of two standard versions.
switch for open wiring:
- Electric drill.
- A drill with a diameter of 6 mm (for wood) or a drill with a diameter of 6 mm (for a concrete or brick wall).
- A Phillips screwdriver for clamping the wire into the terminal contacts and securing the switch housing.
- A screwdriver is an indicator for determining the presence of voltage in the network.
- Knife for stripping the insulating layer of the wire. (in the absence of a special tool for stripping insulation from cable and wire products). A knife is also needed to prepare the input and output holes in the switch housing for wires (cables).
- Pliers for crimping flexible wires. If the wire is solid, pliers may not be needed. But you can also use crimp lugs that match the wire cross-section (for flexible wire).
- Dowel with plug 6x40 (standard size indicated, it may vary depending on local conditions).
- Marker or felt-tip pen for marking “phase/zero” on the wires (for safety reasons).
To ensure safety from electric shock, all tools must have insulated handles to ensure that the metal parts of the tool are insulated from the hands of the installer. A high-quality tool indicates the insulation class or the maximum voltage value in the network of which such a tool is allowed to work.
Switch for hidden wiring.
To install a switch in a network with hidden wiring, you will need the same set of tools as in the previous example, but with a significant addition. You will need a hammer drill with special equipment - a crown for drilling standard holes in concrete and brick walls. Since the working part is recessed into the wall, you cannot do without a hammer drill.
You will also need a special construction mixture to fix the plastic switch housing in the drilled hole. Construction plaster, plaster, etc. are suitable for this purpose.
Connection instructions
Let's look at the installation process using the example of a switch for hidden wiring. This process is preferable since the aesthetics of the home interior require hidden wiring.
1. Drill a hole in the wall using a hammer drill and a special crown.
2. Using a chisel or screwdriver, remove the destroyed wall elements.
3. Check that the hole matches the dimensions of the plastic switch housing.
4. Punching a groove for electrical wiring. (Down to the baseboard, as in this example, or to the junction box).
5.Cutting a template hole in the plastic switch housing for electrical wiring.
6. Wetting the prepared hole with water for better contact with the building mixture-fixer.
7.Applying the building mixture into the hole and installing the housing.
8. Installation of the plastic case.
9. Removing excess mixture solution.
10. Leveling the surface of the solution.
11. Final position of the switch body after the solution has hardened.
12. The next stage is connecting the working part of the switch and installing it in the housing.
For safe operation, we turn off the voltage of the network into which we connect the device. We first determine the phase and neutral wires using a voltage indicator. We mark the wires so as not to get confused in the future.
After installation of the plastic housing is completed and the mixture has hardened, we insert the phase wire into the switch housing. We connect the phase wire to the terminal of the incoming contact of the device.
We connect two outgoing phase wires, respectively, to the outgoing terminals of the contacts. We get the following.
13. All that remains is to install the switch keys and it is ready for use.
Provided that the lamps are already connected, we apply voltage to the network and check the operation.
To make the connection process more clear, below is a video on this topic.
How to install and connect a two-key switch with your own hands: video
Possible errors and ways to solve them
When connecting the working part, you can confuse the phase and neutral wires; to avoid this, you need to mark them in a timely manner.
The position of the switch keys is set as follows as standard:
Installing switches is not a particularly labor-intensive, although multi-step process. If you follow the above recommendations and their consistency, problems should not arise. It is necessary to remember the main rule of electricians. Before starting work (installation, repair of electrical appliances and equipment), turn off the power supply and check that there is no voltage at the workplace. It is very important to take measures to prevent the voltage from being switched on in the mains by mistake. To prevent anyone from turning on the circuit breaker that you turned off before starting work by mistake, you should hang a sign on it that says “Do not turn on, people are working!” or lock this machine in the box with a padlock (if there is one). Safety first!
This article discusses what a pass-through switch circuit should look like from two places, allowing you to control the lighting of the room (turn it on and off) from different points. In addition to the fact that different groups of lamps can be connected to different switches, sometimes you need to turn on the light in one place, and after passing through the room, turn it off in another. This is implemented using cross switches.
There are many places in an apartment or house where the ability to turn off the lights from several points is useful. The most typical case is a long corridor or garage, where a couple of switches eliminates the need to first turn off the lights and then walk to the opposite exit in the dark.
Another example is in the bedroom, it would be convenient to place one switch at the entrance and the second at the bedside table. It is convenient to turn on the light when you enter, and when you go to bed, turn off the light without getting out of bed.
Marking and appearance of the pass-through switch
Also, this principle of turning on/off the light is very useful for the entrance of an apartment building, when the lighting of the entrance and stairs can be turned off on your floor, having already reached the apartment (but it must be taken into account that in this way all the lighting will be turned on or off on all floors at the same time).
And if you want to control each individual light bulb from several places, then this will require installing a separate control circuit and switches for the lamps on each floor.
Controlling a light bulb from two places (pass-through switch diagram from two places)
The correct name for the type of switch you need is a "through switch". Although it looks like a typical one-key switch, it is called a switch for a reason. This device, in both positions of the key, does not break the electrical circuit, but switches from one contact to another.
In a typical circuit with two switches installed in the open circuit between the light bulb and the phase, two wires are laid between the switches and pressing a button can turn the lighting on or off, regardless of the position of the second switch.
That is, if the circuit is open, then pressing the key of any of the switches will close the circuit, and a second switch on the same or on a second switch will open it.
Assembling such a circuit is not difficult at all; it is enough to find on each switch a common terminal that does not switch, at one of the switches a phase wire is connected to this terminal, at the second switch a wire from a light bulb or lamp is connected to the common terminal.
And connect the remaining two terminals on each switch between the switches in any order. The zero goes straight to the light bulb, as it should be. So, in the end, after assembling this circuit, you will have five wires running through the junction box. Sometimes such switches are made double, that is, one housing with two independent keys and six terminals.
Light control from three or more places (pass-through switch diagram from two places)
If the diagram of a pass-through switch from two places is already more or less clear, then to implement the same task, but with three switches, you will need, in addition to the already familiar pass-through switches (2 pcs.), one cross switch. Externally, it can only be distinguished by four wire terminals, and is a typical single-key switch. There are also double cross switches with two keys and, accordingly, eight terminals.
In the case of lighting control from three points, pass-through switches are placed at the beginning of the switching circuit and at the end, and a cross switch is placed between them. This can be seen in the standard diagram of how crossover and pass-through switches are connected.
A crossover switch is so named because it has two power lines passing through it. And this device switches them crosswise with each keystroke. A typical example of using a circuit of three switches is the entrance and stairwells of a three-story building. Pass-through switches are installed on the first and third floors, and cross switches on the second.
Now you can turn on the light when entering the entrance or leaving any apartment on the staircase; any of the switches will close the circuit. And when you leave the entrance or when you go up to the desired floor, again, use any of the switches to independently turn off the light bulb.
It should be noted that if there are four or more lighting control points, then in this circuit the number of cross switches in the middle of the circuit simply increases.
So, having understood the difference between special switches and household lighting switches, you know exactly how the pass-through switch circuit is assembled and switched from two places. As you can see, it is not at all difficult to control one light bulb from many places. Now, if you want to control each lamp separately from several places, then you will have to install a lot more circuits.
Long gone are the days when all circuits for switching on electrical devices were adjusted to the switching that was available. However, sometimes switches and sockets were difficult to get. But today is a completely different time; there are many functional and technically advanced devices on sale. You can do the wiring in such a way that it will be as convenient as possible to turn on and off electrical appliances. In this article we will look at how to connect two switches to two light bulbs, and most importantly, we will decide in which cases it is reasonable to use such a circuit.
Advantages and uses of two-switch control circuits
Surely everyone knows the classic scheme by which one lamp is connected. To do this, you need one switch, which must be located in a convenient and accessible place. With its help, the lights in the rooms will turn on and off. This can be inconvenient at times, as the room may be too long and you will walk most of the way in the dark.
The article will look at how to connect two switches to two light bulbs and control them from two or even three places at the same time. The main use cases for control using two switches:
- In premises and equally in buildings with two entrances. This could be a barn, garages, outbuildings for animals or birds. If you install a switch at each entrance, you won't have to walk through the dark every time to turn the light on or off. After all, sometimes it happens that you enter one door and exit through the opposite one. Therefore, you need to consider how to connect two switches to two light bulbs and control them from different places.
- This scheme will be very useful if you have long galleries, corridors, alleys and paths in the garden. You can use lighting when moving in almost any direction. You can turn it off immediately after completing the section.
- Even in apartment buildings you can install such wiring. For example, in the entrance between the floors of a two-story building. In this case, using two switches will be both economical and convenient. But before you make two switches, you need to consult with your neighbors.
- It will be very useful to use two switches in the bedroom. Place one switch at the entrance, and place the second near the bed. In this case, you will not need to get out of bed to turn the light on or off. This will be appreciated by home owners who have a fairly large bedroom.
Features of using two switches
As can be seen from the connection diagram of two switches given in the article, no matter what position they are in, power is supplied to the lighting fixtures, and it is possible to turn it off. It is impossible to implement this circuit using conventional switches. You will have to purchase gateways, which have appeared on the market relatively recently.
Cross switches
The regular switches found in most homes cannot be wired together to work the way we want them to. You can, of course, cheat the switch.
Cross switches exist, but they are much more complex and can be used in conjunction with pass-through switches to control electrical appliances from multiple points. They can be installed instead of a pass-through type switch, but they are more expensive.
Pass-through switches
It is not much different from ordinary ones in appearance. It has a housing, three terminals for connecting wires, 1 or 2 keys. As for the crossover switches, they have 4 terminals for connecting electrical wires. If you need to control two groups of lamps on one luminaire, use only pass-through switches with two keys.
Connecting a two-key switch to two light bulbs is not difficult. Such devices have 6 terminals for connecting wiring. As for conventional switches, they have only 3 terminals. Cross connectors have 8 terminals for connecting wires.
As for the internal design features, a circuit consisting of two lines is connected to the pass-through switch. Regardless of the position of the key, one line will always be closed and the other open. It turns out that when you connect a two-key switch to two light bulbs, the circuit that passes through it does not open. This can be seen in the diagram given in the article.
Connecting switches
There is only one way to connect two pass-through switches in order to switch two electrical devices, so you cannot make a mistake. But if you don’t know, it’s better to refer to the diagram - it has certain difficulties. Further in the article there is a diagram according to which you can connect one lamp.
This is a typical diagram, which shows that pass-through switches are connected in series to the power supply circuit break, and the pass-through switches are connected with one two-wire wire. If you look closely at the diagram, you can see that the power can be opened and closed at any position of the switches.
Circuit assembly
Assembling such circuits is not difficult. For switches, the input for 0 or phase is located on one side of the case, and the two outputs are on the other, so you can safely connect two outputs, the order does not matter. Having connected switches, it is necessary to connect the remaining electrical wiring and connect the lamp. It is imperative to use a device to automatically turn off the electricity - this will protect the circuits from short circuits.
A correctly assembled double switch connection diagram allows you to control two different lighting groups from two places independently of each other. Two two-key pass-through switches will operate in two directions.
Installation instructions:
- Two two-key switches are mounted at selected locations in installation boxes (socket boxes).
- All groups of connected lighting are placed: lamps, sconces or a chandelier with several points of light. Each light source must be connected to one three-wire cable: phase (L), protective (ground), working zero (N).
- A cable of the required length (3x1.5 mm2) is selected, taking into account the fact that 6 contacts - two three-core cables - are suitable for the switches.
- In the distribution box (BK), the wires are connected according to the diagram.
- It is possible to install such a circuit using four single pass-through switches, but replacement will not be rational. Installing double pass-through switches is more profitable, as it saves cables and junction boxes.
A double pass-through switch can be converted into a single crossover switch. To do this, the contacts are connected to each other, and the keys are secured together to work together at the same time.
much simpler and can help organize control of electric lighting from two points.
You can find out how to choose and install the right ventilation system for a country house by clicking here.
Also, any pass-through switch can be used as a regular one. In this case, one of the contacts is either not connected at all, or is also connected for another independent adjustment of the existing lighting line. Now you know how to properly connect, or as electricians say, disconnect, a two-key pass-through switch.
First of all, before choosing and purchasing, you need to decide what it is - a pass-through switch, what it is needed for, and how it differs from the usual one, two and three-key switches.
A single-key pass-through switch is necessary to control one circuit or lighting line from several points located in different parts of the room or the entire house. That is, with one switch you turn on the lighting when entering a room or corridor, and with another, but at a different point, you turn off the same lighting.
Very often this is used in bedrooms. I went into the bedroom and turned on the light near the door. I lay down on the bed and turned off the light at the headboard or near the bedside table.
In two-story mansions, he turned on the light bulb on the first floor, climbed the stairs to the second and turned it off there. 
Selection, design and differences of pass-through switches
Before assembling such a control scheme, here is what you should pay special attention to:
1 To connect a pass-through light switch you need three-wire cable - VVGng-Ls 3*1.5 or NYM 3*1.5mm2
2 Do not try to assemble a similar circuit using ordinary switches. The main difference between regular and pass-through ones is the number of contacts. Simple single-key ones have two terminals for connecting wires (input and output), while pass-through ones have three! 
In simple terms, the lighting circuit can be either closed or open, there is no third option.
It is more correct to call a pass-through not a switch, but a switch.
Since it switches the circuit from one working contact to another.
In appearance, from the front they can be absolutely identical. Only the pass key can have an icon of vertical triangles. However, do not confuse them with reversible or crossover ones (more about them below). These triangles point in a horizontal direction. 
But from the reverse side you can immediately see the difference:
- the pass-through has 1 terminal on top and 2 on the bottom
- a regular one has 1 on top and 1 on the bottom
Due to this parameter, many people confuse them with two-key ones. However, two-key ones are also not suitable here, although they also have three terminals. 
The significant difference is in the operation of the contacts. When one contact is closed, pass-through switches automatically close the other, but two-key switches do not have such a function. 
Moreover, there is no intermediate position when both circuits are open at the gateway.
Connecting a pass-through switch
First of all, you need to correctly connect the switch itself in the socket box. Remove the key and the overhead frames. 
When disassembled, you can easily see the three contact terminals. 
The most important thing is to find the common one. On high-quality products, a diagram should be drawn on the reverse side. If you understand them, you can easily navigate through it. 
If you have a budget model, or any electrical circuits are a bit of a mystery to you, then an ordinary Chinese tester in circuit continuity mode, or an indicator screwdriver with a battery, will come to the rescue.
Using the tester's probes, alternately touch all the contacts and look for the one on which the tester will “squeak” or show “0” at any position of the ON or OFF key. It's even easier to do this with an indicator screwdriver. 
After you have found the common terminal, you need to connect the phase from the power cable to it. Connect the remaining two wires to the remaining terminals.
Moreover, which one goes where does not make a significant difference. The switch is assembled and secured in the socket box. 
Do the same operation with the second switch:
- look for the common terminal
- connect the phase conductor to it, which will go to the light bulb
- connect two other wires to the remaining ones
Connection diagram of the pass-through switch wires in the distribution box
Scheme without grounding conductor
Now the most important thing is to correctly assemble the circuit in the junction box. Four 3-core cables should go into it:
- power cable from lighting circuit breaker
- cable to switch No. 1
- cable to switch No. 2
- cable for lamp or chandelier
When connecting wires, it is most convenient to orient them by color. If you use a three-core VVG cable, then it has two most common color markings:
- white (gray) - phase
- blue - zero
- yellow green - earth
or second option:
- White gray)
- brown
- black
To choose a more correct phasing in the second case, follow the tips from the article "" 
Connect the neutral conductor from the cable of the input machine and the neutral going to the lamp at one point using the terminals of the car. 
Similar to the neutral wires, you combine the “ground” from the input cable with the “ground” of the outgoing cable for lighting. 
This wire is connected to the lamp body. 
The phase from the input cable must be connected to the phase of the outgoing wire to the common terminal of the pass-through switch No. 1. 
And connect the common wire from pass-through switch No. 2 with a separate wago clamp to the phase conductor of the lighting cable. 
Having completed all these connections, all that remains is to connect the secondary (outgoing) conductors from switch No. 1 and No. 2 to each other. And it doesn’t matter at all how you connect them. 
You can even mix up the colors. But it’s better to stick to the colors so as not to get confused in the future.
The basic connection rules in this diagram that you need to remember:
- the phase from the machine must go to the common conductor of the first switch
- and the same phase should go from the common conductor of the second switch to the light bulb
- the remaining two auxiliary conductors are connected to each other in the junction box
- zero and ground are supplied directly to the light bulbs without switches
Changeover switches - lighting control circuit from 3 places
But what if you want to control one lighting from three or more points. That is, there will be 3, 4, etc. switches in the circuit. It would seem that you need to take another pass-through switch and that’s it.
However, a switch with three terminals will no longer work here. Since there will be four connected wires in the junction box.
Here a changeover switch, or as it is also called a cross, cross, or intermediate switch, will come to your aid. Its key difference is that it has four outlets - two at the bottom and two at the top. 
And it is installed precisely in the gap between two passageways. Find in the junction box two secondary (not main) wires from the first and second pass-through switch.
You disconnect them and connect a changeover between them. Connect the wires that come from the first to the input (follow the arrows), and those that go to the second to the output terminals. 
Always check the diagram on the switches! It often happens that their entrance and exit are on the same side (top and bottom). For example, the connection diagram for a Legrand Valena changeover switch: 
Naturally, there is no need to stuff the changeover itself into the junction box. It is enough to lead the ends of a 4-core cable from it there. Meanwhile, you place the switch itself in any convenient place - near the bed, in the middle of a long corridor, etc. You can turn the light on and off from anywhere. 
The most important advantage of this circuit is that it can be changed indefinitely and add as many changeover switches as you like. That is, there will always be two passing ones (at the beginning and the end), and in the interval between them there will be 4, 5 or at least 10 crossover ones. 
Connection errors
Many people make a mistake at the stage of searching and connecting the common terminal in the pass-through switch. Without checking the circuit, they naively believe that the common terminal is the one with only one contact.
They assemble a circuit in this way, and then for some reason the switches do not work correctly (they depend on each other).
Remember that on different switches the common contact can be anywhere!
And it is best to call it, what is called “live”, with a tester or an indicator screwdriver. 
Most often, this problem is encountered when installing or replacing pass-through switches from different companies. If everything worked before, but after replacing one circuit the circuit stopped working, it means the wires were mixed up.
But there may also be an option that the new switch is not pass-through at all. Also remember that the lighting inside the product cannot in any way affect the switching principle itself.
Another common mistake is incorrectly connecting crossovers. When both wires are placed from pass-through No. 1 to the upper contacts, and from No. 2 to the lower ones. Meanwhile, the cross switch has a completely different circuit and switching mechanism. And you need to connect the wires crosswise. 
Flaws
1 The first of the disadvantages of pass-through switches is the lack of a specific ON/OFF key position, which is found in conventional ones.
If your light bulb burns out and needs to be replaced, with such a scheme it is not immediately possible to understand whether the light is on or off.
It will be unpleasant when, when replacing, the lamp may simply explode in front of your eyes. In this case, the easiest and most reliable way is to turn off the automatic lighting in the panel.
2 The second drawback is the large number of connections in junction boxes.
And the more light points you have, the greater the number of them will be in the distribution boxes. Connecting the cable directly according to diagrams without junction boxes reduces the number of connections, but can significantly increase either the cable consumption or the number of its cores.
If your wiring goes under the ceiling, you will have to lower the wire from there to each switch, and then lift it back up. The best option here is to use pulse relays.