Cross circuit breaker: purpose and device + wiring diagram and installation

An electrical cross-over switch is a device designed for use as part of electrical communications circuits. In particular, this class of devices is actively used when it becomes necessary to organize control of light sources from different points. As a rule, the scheme involves the introduction of this device as an additional component to the existing pass-through switches.

In this article, we consider the design and electrical circuit of the device itself, as well as the connection features in various versions. We will supplement the material with visual diagrams, a photo and a video on self-assembly.

Cross circuit breaker design

The device itself, the inverse switching of power lines is simple. However, due to the multi-point circuitry characteristic of such devices, implementation difficulties can become real. Therefore, it is logical to consider the design of the device, as well as the connection diagram.

The purpose of the communicator is obvious - the connection of electrical circuits for domestic (commercial) purposes, where the voltage level does not exceed 250 volts. The standard version of the devices is designed for operation inside dry, warm rooms, suitable for the established standard of protection class (IP20).

Outwardly, it does not stand out from the traditional designs of light switching devices. However, the internal reversing switch system has a slightly different circuit design

The installation of cross switches is carried out in the traditional way (similarly mounting a conventional switch light) with the mounting box mounted on screws, or internal mounting is done with the base fixed to the wall with metal tabs.

The body of the device is usually made on the basis of shock-resistant non-combustible technopolymer. All structural parts for outdoor installation are resistant to ultraviolet radiation.

Modern products are distinguished by the use of high quality materials for external framing. Technical plastic is not affected by ultraviolet and light rays.

The mechanics of cross-switches for current 10A are equipped with quick-clamping contact groups. Instrument mechanics for current 16A has screw terminals. For ease of connection, the terminals (phase and zero) are usually marked with a different color.

The terminals of the switches are designed for connecting conductors made using single-core or multi-core pull technology. Single conductor cross section up to 2.5 mm²stranded up to 4 mm² (for 16A switches).

The electrical circuit of the device

If we consider the circuitry of cross-switching devices, it should be noted that there are different designs of devices in terms of the number of contact groups. Simple and frequently used devices (single-key) have 2 floating (moving) contacts and 4 stable (fixed) contacts.

Circuit configuration switch with two keys. Manufacturers, as a rule, apply the switching diagram directly on the back wall of the plastic base of the device. The user can only do everything according to the scheme

A more complex design of cross-circuit breakers (two-three-key designs) is already marked by the number of communication groups of up to 4-6 movable and up to 8-12 fixed contacts.

A distinctive feature of this type of devices is their "dependent" installation. In other words, cross-functional circuit breaker designs are not installed without a pair of conventional switches.

That is why, choosing an intermediate action device, you should pay attention to the number of working contacts. For intermediate switches, the number of working terminals is always at least four.

The terminal block of the switch, but not from the group of those devices that are designed for switching in the reverse switching mode. This is the appearance of the rear wall of the passage switch, where no more than 3 working contacts

Thanks to the use of such devices, it becomes possible to create more flexible and convenient operating schemes for controlling light devices. Particularly relevant is the practice of using cross-devices in the infrastructure of industrial enterprises.

Analysis of the schematic of the contact groups of the device

If you take the classic (single-key) design of the device manufactured, for example, by ABB, and deploy it to the user with the back side, approximately the following picture will open.

There are 4 pairs of terminals on the base board, each of which is marked with the corresponding symbols - in this case, “arrows”. By a technical designation of this kind, the manufacturer gives the user information about the correct connection of the device.

This is how the terminal wiring of the device with the reverse locking function looks. Differences from the design shown above are obvious. Based on these signs, the desired device configuration is usually chosen

Incoming “arrows” indicate the general (cross over) contact group. Outgoing “arrows” mark a permanent contact group.

Schematically, the interaction of the groups looks like the following figure:

The colored lines conditionally show how the contact groups are located inside the intermediate switching device. Each pair of working terminals is marked with symbols indicating the input and output groups

Conductors from the first come to the terminals of the general (cross over) group of the contactor passage switchinvolved in the electrical circuit. Accordingly, from the terminals of the second (permanent) group of the contactor, conductors come out that connect to the through switch number two, also prudently included in the circuit.

This is a classic variation using two walk-through and one reversing devices.

The scheme for introducing one cross device in a circuit between two devices of continuous operation. Typically, this solution is typical for the circuitry used in domestic premises

A device designed to play the role of a reversing switch can actually be used in one of two modes of switching an electric circuit:

1. Direct switching - An analogue of two devices through passage.
2. Cross switching - main destination.

The configuration of the first option, in fact, is represented by the functionality of a direct connection with the possibility of communication or disconnection.

The second configuration method (by setting jumpers) puts the device into operation according to the inversion switching scheme.

The reverse switching device supports configuration (jumpers) for one of two possible mode functions. Thus, the cross-type switch acts as a kind of universal device

Thus, the intermediate switches look functionally not just as switches of artificial light sources, but as universal switches. This factor expands the functionality of such devices, making them convenient for use in various installation options.

Mounting features and circuit connection

Mount inverted switches using standard methods and methods used in construction or in the electrical industry. Convenient location of the device is preliminary planned.

Then, taking into account the selected mounting point and binding to the general electrical circuit, draw a wiring diagram for the intermediate switch and working with it in a pair of walk-through switches.

As part of the project development procedure, the method of laying conductors is determined - surface or internal.

Example of installation of a passage switch according to the installation variant of internal wiring. In exactly the same way, the cross device is mounted, with the only difference being that four cable conductors are connected to it

Taking into account the chosen method, the installation infrastructure is prepared (strobes, holes, mounting plugs, junction boxes).

On the finished infrastructure, electrical wiring lines are pulled, wires are routed in the distribution boxes, the ends are routed directly to the connection to the through and intermediate switching devices.

Option # 1 - the nuances of connecting an intermediate device

The ends of the conductors withdrawn from the junction box for connection with an intermediate switch (4 in total) must be prepared. In particular, insulation is removed in the section from the end along the wire, approximately 10-12 mm long.

By the way, many branded circuit breakers have a special marker on the chassis, by which it is easy to measure the required length of the insulation stripping.

The chassis of the proprietary device, where the design provides for the manufacture of a special measuring cut-out. Thanks to this marker, the user will always strip the wire strictly according to the instructions

Now it is necessary to identify two conductors emanating from the first passage switch installed in the circuit. Typically, all conductors are marked for ease of identification even at the stage of wiring the circuits.

These two wires are connected at two input terminals (in this case, spring type) of the intermediate switching device. The remaining two are wired to the output terminals.

Marking with arrows on the chassis reduces the risk of incorrect connection of the device. The current rating and the permissible operating voltage level are also indicated here.

The chassis prepared in this way needs to be put in place - installed inside building socket (for internal installation) or fix directly to the wall surface (external surface-mounted installation).

Fastening the switch chassis by directly screwing in the screws. Meanwhile, the installation of the internal type often involves mounting side metal spacers

Under conditions of internal installation, the chassis is usually fixed with spacer brackets or direct screw fasteners. With overhead mounting of switches, direct screw mounting is traditionally used. Further, a frame is placed on the chassis and a cover key is put on the control lever of the switch.

Option # 2 - circuit solutions for several devices

Intermediate installation switches are an integral part of circuit solutions, where the principle of control from more than three points remote from one another is implemented.

Theoretically, there can be many such control points for artificial light sources. However, options for three or four, with a maximum of five positions, are practically being implemented. Since with each new input of the device the general wiring diagram is complicated.

Communication circuit of the lighting circuit, where two cross-circuit breakers are paired with two walk-through switches. This is a control option from four independent positions.

For an example, we can consider a four-position wiring when two pass-through and two reversing switching devices are used from the main components. In such a scheme phase wire fail on the movable contact of the through switch.

When a current is supplied to the network, it passes through the closed contact group of the loop-through device and is supplied to the movable contact of one of the two cross-over switches.

Further, from the output terminal of the reversing device, the current flows to the second switch of the same type - to its movable contact group and through the output terminal it enters the permanent contactor of the second pass-through switch.

If the cross over switch of this switch closes the circuit, from its output current flows to the light device. Through the filament of the lamp the common circuit is closed on the zero bus. Lamps are on. Now, if for the sake of experiment (and in practice, too) one by one to set any of the devices to the “off” state, the lamp lamps will go out in each of the four cases.

Schematic of a multi-switch with the participation of reverse-acting devices. Theoretically, with this solution, an unlimited number of devices can be used. Or a number limited only by the structural nuances of the premises

But if you turn off all four at the same time, this peculiar communication group will simply switch to another switching line and the lamp lamps will remain energized - they will continue to burn.

The experiment with reversing devices clearly shows the functionality of the cross four-position switch circuit. In any of the four positions, control of the light device is available.

Conclusions and useful video on the topic

Video on the practice of controlling light fixtures using a cross switch.

How to install and separate the line of wires from the passage switches to the cross and how to connect the devices:

The advantages of using PV are obvious, both from the point of view of user convenience and in terms of energy savings. That is why the considered electrical appliances are rapidly gaining popularity both in everyday life and in the industrial and economic sphere.

Do you want to supplement the above material with useful comments, wiring diagrams or installation recommendations? Or maybe you noticed inaccuracies or inconsistencies in this article? Please write your comments and tips in the comments section.