In this article we will learn about the Classification of circuit breaker and working application of circuit breaker. We will also discuss about different types of circuit breaker Air circuit breaker, Oil circuit breaker, Air blast circuit breaker. Vaccum circuit breaker etc.
Classification of Circuit breaker And Working Application of Circuit Breaker
Circuit Breaker working and Application
Now we are going to discuss about the classification of circuit breaker and working application of circuit breaker.
Arc is a phenomenon occurring when the two contact of circuit breaker separate under heavy load or fault or short circuit condition. This arc are depends on :
- Nature and pressure of medium.
- External ionizing and deionizing agent.
- Voltage between electrode and its variation with time.
- Nature,shape and separation of electrode.
Now we will study in detail about the classification of circuit breaker and working application of circuit breaker.
Method of Arc interruption
There are two method of quenching arc
1. In this the arc is interrupted at current zero position that occur 100 times a second in case of 50 HZ power system frequency.
- High Resistance interruption
In this the arc is increased by elongating and splitting the arc so that arc is fully extinguished.
It is a piece of equipment to break a circuit automatically under fault condition. It breaks a circuit either manually or by remote control under normal condition and under fault condition .
Classification of Circuit Breaker and Working Application of Circuit Breaker
These are different type of circuit breaker
- Air break circuit breaker
- Oil Circuit Breaker
- Minimum Oil Circuit Breaker
- Air blast circuit breaker
- SF6 circuit breaker
- Vacuum Circuit Breaker
Comparative study of different type of conventional circuit breakers
Bulk Oil Circuit Breakers
Advantages of Bulk Oil Circuit Breakers
- Simplicity of construction
- High rupturing capacity
- Suitability for automatic as well as manual operation
- Possibility of locating current transformers in bushings
Disadvantages of Bulk oil circuit breakers
- Fire hazard
- Explosion hazard
- Necessity for periodic inspection of the quality and quantity of oil in the tank.
- Large volume of high grade mineral oil which is not only costly,but is scarcely available in our country.
- Necessity of storing large quantity of oil in the generating stations and substations.
- Unsuitability for indoor installation.
- Unsuitability for repeated cycles of operation in connection with automatic reclosing.
- Greater wear and tear of the contacts resulting in their frequent replacement.
- Comparatively large quantities of steel required for the construction of the tank.
- Larger size and greater weight. These are classification of circuit breaker and working application of circuit breaker.
Minimum Oil Circuit Breakers Working Application
Advantages of Minimum Oil Circuit Breakers
- Comparatively smaller quantity of oil.
- Comparatively less weight and size.
- Lower Cost.
- Suitable for both automatic and manual operation
- Easier access to the contacts
Disadvantages of Minimum Oil Circuit Breaker
- Fire and explosion hazards do exits in this type of circuit breaker although to a lesser extent than in bulk oil circuit breakers.
- Totally unsuitable for repeated cycles of operation.
- Requires a more frequent inspection and replacement of oil.
- Greater contact damage.
- Difficulty in locating current transformers.
- Comparatively lower rupturing capacity.
Air blast circuit breakers Working Application
Advantages of Air blast circuit breakers
- No explosion or fire hazard.
- Very fast in operation.
- Suitable for rapid reclosing
- Very high rupturing capacity.
- Opening unloaded transmission lines or highly capacitive systems not present much difficulty.
- Less contact damage.
- Very easy access to the contacts.
- Comparatively less weight
Disadvantages of Air blast circuit breakers
- They require the installation of a complete compressed air system consisting of electric motor, air compressor, air tight tubes, etc.
- Their construction is much more complicated.
- Their cost is higher.
- Requires highly trained personnel for their maintenance.
- They are more sensitive to RRRV (rate of rise of recovery voltage). These are also descibe title which is classification of circuit breaker and working application of circuit breaker.
Circuit Breaker Rating
It is the characteristics value that define the working condition for which the circuit breaker is designed. A circuit breaker should have following rating
- Rated voltage & current
- Rated frequency
- Rated breaking capacity
- Rated making capacity
- Rated operating duty
- Rated short-time current
- Rated Current
It is designed limit of current in rms voltage above nominal system voltage for which the circuit breaker is designed.
It is designed limit of current in rms ampere which it shell be capable of carrying continuously without exceeding the limit of observable temperature rise.
The frequency at which the circuit breaker is designed to operate at standard frequency is 50 HZ.
When the contact of breaker are separated, an arc is streaked between then this arc delays the current interruption process and also generate heat which may cause damage to system or circuit breaker. It is also usefull to describe of classification of circuit breaker and working application of circuit breaker.
Air blast circuit breaker Working Application
In this circuit breaker compressed air of 20-30 Kg/cm2 is used for arc quenching medium. They arc suitable for 132KV and above they are following types.
- Air blast type
- Cross blast
Advantage of Air blast circuit breaker
- High speed operation
- Elimination of fire hazards.
- Suitability for frequent operation.
- Facility for high speed reclusive.
- Short arcing time
- Less burning of contacts.
Disadvantages of Air blast circuit breaker
- Problem of current chopping.
- Problem of restriking voltage
- Need of Air-compressor plant
- Produce high level noise
SF6 Circuit Breaker Working Application
It use inert, nontoxic and non inflammabl heavygap for arc medium.
Electro negativity of SF6 Gas
It has high affinity for electron when a free electron comes and collide with a natural gas molecule,the electron is absorbed by the neutral gas molecule and negative ion is formed. This concept is called electro negativity of SF6 gas. These are also describe above title which is classification of circuit breaker and working application of circuit breaker.
Characterstics of SF6 Gas
- It is good dielectric strength
- Excellent arc quenching property
- It is insert non toxic, heavy and noninflammable.
Advantage of SF6 circuit breaker
- Noise less operation
- Reduced moisture problem
- Minimum current chopping
- Performance is independent is independent of ambient condition.
- Elecrcal clearance is reduced
- No carbon particl formed.
Application of Vacuum Circuit Breaker
- Reactor switching
- Transformer switching
- Capacitor band switching
Hence these are Classification of circuit breaker and working application of circuit breaker. From above article we have learn about application of different kind circuit breaker and their advantages and disadvantages. We have studied about the working of different kind circuit breaker.