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Vacuum circuit breaker arc extinguishing principle

By:Nader Updated:September 08,2020 18:25PM

Vacuum circuit breaker is a vacuum (a vacuum degree of 10-4mm Hg or less) with good arc-proof insulating properties and performance characteristics, the part of the circuit breaker contacts mounted within the housing and a vacuum circuit breaker made. Vacuum circuit breaker having a small size, light weight, low noise, easy to install, and easy maintenance. In particular, the circuit for frequent operation.

Vacuum interrupter arc ignition is instantaneous due just to divide the vacuum circuit breaker, the contact surface of the metal vapor evaporation, and the arc caused by the free form. Vacuum interrupter chamber large arc pressure of the arc column, but also a great difference in mass density, and metallic vapor arc column (charged particles) will quickly spread to the outer contact, to aggravate the effects of free plus the arc is the arc column elongated, attenuation, resulting in better cooling, quickly extinguish the arc, the insulating dielectric strength rapidly recovered, thereby preventing reignition after the zero crossing of the alternating current nature.

Vacuum interrupter is a vacuum interrupter of the circuit breaker and the insulating member. The main movable contact, stationary contacts, movable end running arc, moving the end flanges, the end flanges static, ceramic column, stainless steel support flange, shields, conductive rod movement, the glass bulb and bellows, cleaned after the glass sealing process, vacuum welding, arc welding, the exhaust gas from other process program package. All major components are sealed in a glass bulb, the bulb is not only function as a sealing flange through movement, but also play an insulating effect. A resilient member dynamic sealing bellows system through the vacuum interrupter chamber can be accomplished under the action of opening and closing operation of the actuator mechanism, but does not destroy the degree of vacuum.

Manufacturing a vacuum interrupter as a whole, is not removable, the whole should be replaced after damage.

Dielectric strength of the vacuum arc extinguishing medium is based on the use of a high vacuum (typically less than 10-4mm Hg pressure rare gas) and arc product (charged particles and metal vapor) In this gas has an extremely high diffusion velocity, the principle of the arc current zero, contact gap dielectric strength can be quickly restored achieved together. Metal vapor and charged particles during arcing shield is condensed in the strong diffusion with three runs Archimedean spiral arc grooves an arc current generating a transverse magnetic field in its flow through the line between the contacts , when the arc current rapidly moving in the tangential direction on the main contacts, thereby lowering the temperature of the main surface of the contact, the main contact reduces burning, stable breaking performance of the circuit breaker to increase the life of the circuit breaker .