The knife switch is a special switching device. It is used for switching an electric circuit, for transmitting electricity. Such systems operate using a manual drive. For example, when inspecting or repairing an electrical system, devices of this kind cannot be dispensed with. The cross over switch is generally one of the simplest modifications of the switches of this group.
Application and classification
If we talk about the number of contacts, then these devices can be:
1) Multipolar.
2) Three-pole.
3) Bipolar.
4) Unipolar.
In addition, you can find a cross over switch with a side or central lever.
To place this device often use special protective boxes. At the same time, the control lever is displayed on the outside.
These devices are easily used not only in industrial electrical, but also for domestic purposes. Any changeover switch is universal.
What should I look for when buying?
In order to make the right choice, it is necessary to determine from the very beginning why this switch will be used. After that, you can already move on to other parameters. In addition, it is important to know what is the power of electrical appliances included in a particular network.
Experts mention several parameters that you should pay attention to when visiting specialized stores. This is the operating position, the established uptime, the category of placement according to GOST and climatic design, the rated voltage, the rated breaking current and the number of poles.
How to decipher the marking?
If two numbers are visible on the package, then the second indicates the rated current, and the first indicates the number of poles. If the cross over switch has the letter b in the marking, which means that the side lever is used. C is a designation for the central. When there are two letters, and the second of them is n, this indicates the front connection of the wires. Finally, n and p are the switch and the switch, respectively.
A little bit about the design
The knife-type contact system is an indispensable component of any switches of this type. In addition, there are fixed parts in the form of spring brackets. Metal knives enter them when the system closes. Thanks to this, the cross over switch does not break the contact when used.
Additional Information
The absence or presence of arc chambers - possible designs for devices with a lever drive or side handle. If it is located in the center, then special cameras are always absent. But there are spark arresting contacts. Thus, when the equipment is turned off, it does not depend on how fast the lever rotates. If the current of the device is more than 200 Amperes, for example, there is a changeover switch 400A, then the device is amplified using steel springs.
In addition, the model can be connected to fuses, which provide additional protection. For example, you can find a crossover circuit breaker 250A with just such a design.