Vacuum Circuit Breaker
A vacuum Circuit Breaker is a type of Circuit Breaker where the arc extinguishing happens in a vacuum medium. The activity of turning on and shutting of current carrying contacts and interrelated arc interference happens in a vacuum chamber in the breaker which is known as a vacuum interrupter.
A vacuum that is utilized as the circular segment extinguishing medium in an circuit breaker is known as a vacuum circuit breaker since vacuum invigorates high protecting because of superior arc extinguishing properties. This is reasonable for most standard voltage applications on the grounds that, for higher voltage, vacuum innovation was grown anyway not monetarily practical.
The activity of current-conveying contacts and related circular segment interference occur inside a vacuum office of the breaker, which is known as a vacuum interrupter. This interrupter incorporates a steel curve chamber inside the focal point of evenly positioned clay covers. The upkeep of vacuum strain inside a vacuum interrupter should be possible at 10-6 bar. The vacuum circuit breaker execution essentially relies upon the material utilized for flow conveying contacts like Cu/Cr
Working Principle
The vacuum circuit breaker working principle is, when the electrical switch contacts are opened inside the vacuum, then, at that point, a circular segment can be produced among the contacts through the metal fumes ionization in the contacts. Be that as it may, the circular segment can be extinguished effectively as the electrons, particles and metallic fumes are created all through the curve rapidly gather over the exterior of the CB contacts, so the dielectric strength can be immediately recuperated.
The main component of a vacuum is that once the circular segment is produced inside the vacuum, then, at that point, it tends to be quenched rapidly due to the fast improvement rate in the dielectric strength of the vacuum.
Construction
The vacuum Circuit Breaker contains a steel arc chamber in the middle evenly organized ceramic encasings. The strain inside the vacuum interrupter is kept up with beneath 10-4 torr.
The material utilized for current-conveying contacts assumes a significant part in the exhibition of the vacuum electrical switch. Amalgams like, Copper-bismuth or copper-chrome is the best material to make VCB contacts.
Vacuum Circuit Breaker
From the figure displayed over, the Vacuum Circuit Breaker comprises of fixed contact, a moving contact, and a vacuum interrupter. The moving contact is associated with the control system by hardened steel roar. The curve safeguards are upheld o the protecting lodging with the end goal that they cover these safeguards and is kept from gathering on the protecting nook. The chance of a hole is disposed of because of the extremely durable fixing of the vacuum chamber for that a glass vessel or ceramic vessel is utilized as the external protecting body.
Working
The sectional perspective on a vacuum Circuit Breaker is displayed in the figure beneath when the contacts are isolated because of a few unusual circumstances, a curve is struck between the contacts, the bend is delivered because of ionization of metal particles and relies especially upon the material of contacts.
The circular segment break in vacuum interrupters is not the same as different sorts of circuit breakers. The partition of contacts causes the arrival of fume which is occupied in the contact space. It comprises of positive particles freed from the contact material. The fume thickness relies upon the ongoing in the bend. At the point when the flow diminishes, the pace of fume discharge diminishes, and after flow zero, the medium recaptures its dielectric strength on the off chance that the fume thickness is decreased.
At the point when the current to be intruded on is tiny in a vacuum, the curve has a few equal ways. The absolute current is partitioned into many equal bends that repulse one another and spread over the contact surface. This is known as a diffused arc segment which can be intruded on without any problem.
At high upsides of current, the circular segment gets packed in a little district. It causes fast vaporization of the contact surface. The interference of the curve is conceivable on the off chance that the bend stays in a diffused state. On the off chance that it is immediately taken out from the contact surface, the arc segment will be re-strike.
Arc segment termination in vacuum breakers is enormously affected by the material and state of the contacts and the strategy of thinking about metal fume. The way of the circular segment is continued to move with the goal that temperature at any one point won’t be high.
After the last arc segment interference, there is a quickly developing of dielectric fortitude which is impossible to miss of the vacuum breaker. They are reasonable for capacitor exchanging as it will give a re sans strike execution. The little current is intruded on before regular current zero, which might cause hacking whose level relies upon the material of contact.
Advantages
- Vacuum offers the most extreme protecting strength. So it has very superior arc extinguishing properties than some other medium.
- The vacuum Circuit Breaker has a long life.
- Dissimilar to Oil Circuit Breaker (OCB) or air blast Circuit Breaker(ABCB), the blast of VCB is kept away from. This improves the wellbeing of the working staff.
- No fire danger
- The vacuum CB is quick in activity so great for shortcoming clearing. VCB is reasonable for rehashed activity.
- Vacuum circuit breakers are nearly support free.
- No fumes of gas to the environment and Silent activity.
Disadvantages
- The fundamental inconvenience of VCB is that it is uneconomical at voltages surpassing 38 kV.
- The expense of the breaker becomes over the top at higher voltages. This is because of the way that at high voltages (over 38 kV) multiple quantities of the electrical switch are expected to be associated in series.
- Besides, VCBs creation is uneconomical whenever delivered in little amounts.
Applications
The Vacuum Circuit Breaker is today perceived as the most dependable flow interference innovation for medium voltage switchgear. It requires least upkeep contrasted with other Circuit Breaker innovations.
The innovation is essentially reasonable for the most part medium voltage applications. For higher voltage vacuum innovation has been grown, yet it isn’t monetarily plausible. Vacuum circuit breakers are utilized in metal-clad Switchgear and furthermore in porcelain housed circuit breakers.
Types of Circuit Breakers
In this article, we will be going through Circuit Breakers, We will Look at different Types of Circuit Breakers which are categorized as Low Voltage Circuit breakers, Medium to High Voltage Circuit breakers, Circuit Breakers based on Operations, and Gas Circuit Breakers. In Low Voltage Circuit Breaker we will be Going Through MCB and RCCB. In Medium to High, we will be going Through ACB, Oil Circuit Breaker, Vaccum Circuit Breaker, Sulphur Hexafluoride Circuit Breaker, and HDVC Circuit Breaker. Based on the operation of circuit breakers we will be going through Dead Tank Circuit Breakers, Spring-operated Circuit Breakers, and Pneumatic Operated Circuit Breaker. At last, in the Gas Circuit Breaker, we will go through the SF6 Circuit Breaker.
Table of Content
- Low-Voltage Circuit Breaker
- Miniature Circuit Breaker (MCB)
- Residual Current Circuit Breaker (RCCB)
- Medium to High Voltage Circuit Breakers
- Air Circuit Breaker (ACB)
- Oil Circuit Breaker
- Vacuum Circuit Breaker
- HDVC (High Voltage Direct Current) Circuit Breaker
- Dead Tank Circuit Breaker
- Spring-Operated Circuit Breaker
- Pneumatic Operated Circuit Breaker
- Gas Circuit Breakers
- Sulphur Hexafluoride (SF6) Circuit Breaker