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The current electricity prices make you think about saving where you didn’t even think about it before. For example, the lighting on the stairs. It doesn’t matter if it’s in a private or high-rise building, you still need to pay. Before, they just left the lights on. Today you think about turning it off, but running up / down is also joyless. It turns out there is a solution. So that the light does not burn constantly, there are schemes for controlling lamps from several places. That is, one or more lamps can be switched on and off from several points. Switches for this need special. They are called walkways. Sometimes there are names “duplicate” or “flip”. All this is one type of electrical equipment. They differ from the usual ones in a large number of contacts. Accordingly, the connection diagram of the pass-through switch is more complicated. However, you can figure it out.
What does a switch look like and how does it work?
If we talk about the front side, then the only difference is a barely noticeable arrow on the up and down key.
If we talk about the electrical circuit, everything is also simple: in ordinary switches there are only two contacts, in the feed-through (also called changeover) three contacts, two of which are common. There are always two or more such devices in the circuit, and with the help of these common wires they are switched.
The principle of operation is simple. By changing the position of the key, the input is connected to one of the outputs. That is, these devices have only two working positions:
- input connected to output 1;
- input connected to output 2.
There are no other intermediate provisions. Thanks to this, everything works. Since the contact switches from one position to another, electricians believe that it is more correct to call them “switches”. So the pass switch is also this device.
In order not to rely on the presence or absence of arrows on the keys, you need to inspect the contact part. Branded products should have a diagram that allows you to understand what type of equipment you have in your hands. It is definitely on the products of Lezard (Lezard), Legrand (Legrand), Viko (Viko). They are often absent on Chinese copies.
If there is no such circuit, look at the terminals (copper contacts in the holes): there should be three of them. But not always on inexpensive specimens, the terminal that costs one is the entrance. Often they are confused. To find where the common contact is located, you need to ring the contacts among themselves at different key positions. This must be done, otherwise nothing will work, and the device itself may burn out.
You will need a tester or multimeter. If you have a multimeter, set it to sound mode – it beeps when there is a contact. If you have a pointer tester, call for a short circuit. Put the probe on one of the contacts, find which of the two it rings with (the device beeps or the arrow shows a short circuit – it deviates to the right until it stops). Without changing the position of the probes, change the position of the key. If the short circuit is missing, one of these two is common. Now it remains to check which. Without switching the key, move one of the probes to another contact. If there is a short circuit, then the contact from which the probe was not moved is the common one (this is the input).
It may become clearer if you watch a video on how to find the input (common contact) for the pass-through switch.
How to connect the hob is written here, and about installing and turning on the water heater – in this article.
Scheme of connecting a pass-through switch from two places
Such a scheme is convenient in a two-story house on the stairs, in the passage room, in a long corridor. You can also apply it in the bedroom – turn off the overhead light at the entrance and near the bed (how many times did you have to get up to turn it on / off?).
Zero and earth (if any) start up immediately on the lamp. The phase is fed to the output of the first switch, the input of the second is connected to the free wire of the lamp, the outputs of the two devices are connected to each other.
Looking at this diagram, it is easy to understand how the pass-through switch works. In the position shown in the figure, the lamp is on. By pressing the key of any of the devices, the circuit is broken. In the same way, when the position is off, by moving any of them to another position, we will close the circuit through one of the jumpers and the lamp will light up.
To make it clearer what and with what to connect, how to lay wires, here are a few images.
If we talk about the room, then you need to lay the wires approximately as in the photo below. According to modern rules, they should all be located at a distance of 15 cm from the ceiling. They can be stacked in mounting boxes or trays, the ends of the wires are brought into mounting boxes. This is convenient: if necessary, you can replace the broken wire. Also, according to the latest standards, all connections occur only in junction boxes and with the help of contactors. If you make twists, then it is better to solder them, and wrap them well with electrical tape on top.
The return wire of the lamp is connected to the output of the second switch. White indicates the wires connecting the outputs of both devices.
How to connect everything in the terminal box is described in the video.
How to connect the chandelier yourself, read here.
3 point scheme
To be able to turn on / off the light from three places, you need to buy a cross (cross) switch for two switches. It differs from those described earlier by the presence of two inputs and two outputs. It switches a couple of contacts at once. How everything should be organized, see the picture. If you figured out what is above, this one is easy to understand.
How to assemble such a scheme? Here is the procedure:
- Zero (and grounding, if any) starts immediately on the lamp.
- The phase is connected to the input of one of the pass-through switches (with three inputs).
- The input of the second is fed to the free wire of the lamp.
- The two outputs of one three-contact device are connected to the input of a cross switch (with four inputs).
- The two outputs of the second three-contact device lead to the second pair of contacts of the switch with four inputs.
The same scheme, but from a different angle – where to connect the wires on the cases.
And here’s how to breed around the room.
If you need a circuit for four, five or more points, then it differs only in the number of cross switches (for four inputs / outputs). There are always two switches (with three inputs / outputs) in any circuit – at the very beginning and at the very end of the circuit. All other elements are cross devices.
Remove one “crosshair”, get a control scheme of four points. Add more – there will already be a scheme for 6 control places.
To finally put everything in your head, watch this video.
Read about the rules for connecting wires in a junction box here.
Two-gang pass-through switch: wiring diagram
In order to control the lighting of two lamps (or groups of lamps) from several places from one switch, there are two-button walk-through switches. They have six contacts. If necessary, find common wires according to the same principle as in a conventional device of this type, only you will have to ring more wires.
The connection diagram of a 2-key pass-through switch differs only in that there will be more wires: the phase must be supplied to both inputs of the first switch, as well as from the two inputs of the second switch, it must go to two lamps (or two groups of lamps, if we are talking about a multi-track chandelier ).
If you need to organize the control of two light sources from three or more points, you will have to put two cross switches at each point: there are simply no two-button switches. In this case, one pair of contacts is connected to one crosshair, the second to the other. And then, if necessary, they are interconnected. The last two-gang transitional switch in the circuit is connected to the outputs of both crossbars.
If you think about it, everything is not so complicated, and the wiring diagram for a 2-point pass-through switch is generally simple. Lots of wires…