A vacuum circuit breaker is a device designed for operation as part of high-voltage electrical networks. It got its name from a design feature – a vacuum chamber, due to which momentary extinguishing of an electric arc is achieved.

The device is used as switches designed to shut down equipment in case of emergencies or as part of current operation. Let’s take a closer look at what a vacuum switch is and what it is for.

Advantages of vacuum circuit breakers:
High mechanical strength;
High switching life at rated current and breaking current;
Reliable and stable switching on and off with normalized parameters;
Possibility of manual operational shutdown in the absence of operational power supply;
The material and design of the pole prevent the accumulation of dust on its surface;
Does not require adjustments during the entire period of operation.

Indoor vacuum circuit breakers use epoxy molded poles. Outdoor circuit breakers have solid-cast poles in organosilicon insulation. The poles are equipped with state-of-the-art vacuum chambers, which are specially designed and optimally suited for use in cast poles.

Contacts of vacuum chambers are made of special alloys. The burning of the arc that occurs when the contacts are separated when the load is turned off is supported by metal vapors due to the evaporation of the electrode material. The electric arc is gently extinguished during the natural transition of the current through zero, therefore, the possibility of overvoltage during switching of most types of loads is excluded.

Vacuum circuit breakers use a universal electromagnetic drive. Powerful permanent magnets are used to hold the switch in the on or off position. Fixation occurs due to the use of the “magnetic latch” principle, namely, the closing of the magnetic circuit on or off by an armature, which is mechanically connected to the moving contacts of the vacuum chambers.

To control the drive, an electronic control unit is used, which is equipped with a vacuum high-voltage circuit breaker. The control unit can be built into the circuit breaker body or made in a remote version. Shutdown occurs due to the energy of pre-charged capacitors.

The circuit breakers also use spring drives, which, in addition to the rated closing / opening of the circuit breaker, provide the possibility of manual closing and opening.