VACUUM CIRCUIT BREAKER IN MALAYALAM

Vacuum Circuit Breaker
A breaker which used vacuum as an arc extinction medium is called a vacuum circuit breaker. In this circuit breaker, the fixed and moving contact is enclosed in a permanently sealed vacuum interrupter. The arc is extinct as the contacts are separated in high vacuum. It is mainly used for medium voltage ranging from 11 KV to 33 KV.
Vacuum circuit breaker has a high insulating medium for arc extinction as compared to the other circuit breaker. The pressure inside the vacuum interrupter is approximately 10-4 torrent and at this pressure, very few molecules are present in the interrupter.
Their service life is also much greater than any other circuit breaker, and almost no maintenance are required.
Construction of Vacuum Circuit Breaker
It is very simple in construction as compared to any other circuit breaker. Their construction is mainly divided into three parts, i.e., fixed contacts, moving contact and arc shield which is placed inside the arc interrupting chamber.
The outer envelope of vacuum circuit breaker is made up of glass because the glass envelope help in the examination of the breaker from outside after the operation. If the glass becomes milky from its original finish of silvery mirror, then it indicates that the breaker is losing vacuum.
The fixed and moving contacts of the breaker are placed inside the arc shield. The pressure in a vacuum interrupter at the time of sealing off is kept at about 10-6 torr. The moving contacts of the circuit breaker are move through a distance of 5 to 10 mm depending upon the operating voltage.
The metallic bellows made of stainless steel is used to move the moving contacts..
Working Vacuum Circuit Breaker
When the fault occurs in the system, the contacts of the breaker are moved apart and hence the arc is developed between them. When the current carrying contacts are pulled apart, the temperature of their connecting parts is very high due to which ionization occurs. Due to the ionization, the contact space is filled with vapour of positive ions which is discharged from the contact material.
The density of vapour depends on the current in the arcing. Due to the decreasing mode of current wave their rate of release of vapour fall and after the current zero, the medium regains its dielectric strength provided vapour density around the contacts reduced. Hence, the arc does not restrike again because the metal vapour is quickly removed from the contact zone.
Advantages of Vacuum Circuit Breaker
The vacuum circuit breaker has a long life.
• Unlike Oil Circuit Breaker (OCB) or air blast Circuit Breaker (ABCB), the explosion of VCB is avoided. This enhances the safety of the operating personnel.
• No fire hazard
• The vacuum CB is fast in operation so ideal for fault clearing. VCB is suitable for repeated operation.
• Vacuum circuit breakers are almost maintenance free.
• No exhaust of gas to the atmosphere and Noiseless operation.
Disadvantage of Vaccum Circuit Breaker
1.The main disadvantage is the high cost for the vacuum arrangement.

[@eldhoraju3932]

3.3kv to 11kv using vcb (HT) .33kv to above sf6

[@Travelogist_Since_]

Nice 👍

[@musthafamhd756]

Jp sir❣️

[@adithya5039]

Vacuum interrupter itum same ano

[@basicsofelectricalandelect193]

Vaccum interrupter is the part of VCB

[@firosirsha1150]

Sf6 കുറിച്ച് പറഞ്ഞ് തരാമേ?

[@jaguarczcz2769]

Compressor upayogikkuna cb yee patti oru video cheyyamo

[@ufeed-j1e]

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