The three-key walk-through switch is an electrical device designed to control a single light source from different places. Visually, it has many similarities with the usual switches, the principle of operation is the same - closing and opening the lighting circuit.
Why do we need a three-key cross-over switch?
The three-way switch allows the consumer to control one or more light sources from different places. Installation of the device is advisable in rooms with a large area, for example, in country houses and long corridors, in stadiums and concert halls and basements.
A country house with several floors is conveniently equipped with such devices. For example, going up to the second floor, you can turn off the lighting on the first. Also, a triple switch is often set to control street lighting.
Design and principle of operation
The circuit of the triple passage switch externally is no different from traditional devices. The only significant difference - the first is equipped with a working group of the contact group, placed inside the case. In the passage switch, when the key position is changed, one circuit opens, and the other closes immediately. This principle of transferring contacts allows several switches to operate in pairs, controlling a single light bulb.
The principle of operation of the circuit breaker is based on the presence of reverse electrical conductors in the switching device. The work is carried out as follows: when you change the position of the keys, one circuit is closed and the other circuit opens. Due to such features of the device, it would be more correct to call the device not a switch, but a switch. Also, experts refer to it as a backup, cross and cross over switch.
Lighting control from two places
One light source or a whole group can be controlled simultaneously from several remote locations. Often, cross devices are installed on personal plots, in large country houses and long corridors. To connect, you will need a standard circuit for connecting a backup electrical device.
Three sections of the circuit are involved in controlling lighting from two places:
- The cable from the network (220 V) is from the circuit breaker located in the switchboard to the box.
- A wire from one cross-device to the switch box.
- The wire from the second cross device to the opening box.
Three electrical wires are placed in the control box. To control lighting from two places, a two-gang switch of passage switches is used.
Three-point lighting control
You can also install this kind of design in any convenient place. In the circuit, a backup device is connected between ordinary pass-through switches. They can be used at any request of the customer, for example, on a personal plot, in flattering marches, long corridors.
You can build such a device with your own hands, not owning specific knowledge and skills. This requires minor design changes to the two-key crossover device. The output contacts are equipped with two jumpers, and the keys are combined into one, it is enough just to glue them together.It is important that when connecting, the mounting connectors on the keys match the pins located on the switch. It is not at all necessary to make it yourself at home; in construction stores, the seller will offer a large assortment of switches.
Usage example
For example, returning to a private house in the evening, you need to walk to the front door through a dark courtyard. In this case, it is appropriate to mount the crossover switch in several places. Near the switchboard located in the corridor, a switch box and one cross-over switch are mounted. For the second, the most suitable place is on the fence near the gate.
Lighting devices on the street can be small lampposts installed along the infield. In construction stores in the electrical goods departments there is a large assortment of street “chandeliers” with different designs.
It is preferable to lay electric cables from street lighting in trenches underground in special plastic pipes. The optimal depth is no more than half a meter. It does not make sense to take into account the depth of freezing of the soil, since copper electric cables are not afraid of low temperatures.
If one large chandelier hangs in the room, equipped with two groups of lamps or there are several sconces along the corridor, it is better to use not three-key devices, but two-key cross switches in combination with redundant ones. The connection scheme is a little more complicated, but experts note the advantages of this particular connection method.
Of the disadvantages of an electric device, only high cost can be noted. High-quality switches have an attractive appearance and a long service life, does not cause installation difficulties.
You can buy electrical devices in any construction or household store, it is better to give preference to more expensive models, since they are made of high-quality materials, in comparison with budget counterparts.
