As we know about circuit breaker is to protect electrical equipment from abnormal condition such as over load current or short circuit.For Low voltage circuit breaker,i already explain on my last post.Please read my post about miniature circuit breaker (MCB),molded case circuit breaker (MCCB) and residual current circuit breaker (RCCB) for more detail information.
For high voltage circuit breaker,the main contact mechanism normally designed with various method to avoid from damage and provide a better quenching around the contacts surface.The main purpose is to extinguishing any arcs formed as faster as possible.
Types of high voltage circuit breaker
In market now,we can choose two(2) types of design available for high voltage circuit breaker for our application are oil types ( oil filled breaker) and non oil types( air,vacuum and magnetic air). The design is always improve and upgrade by manufacture with new technology and add more efficient value to protect our equipments.
1) Magnetic-air circuit breakers
This breaker use a combination of powerful magnetic field with a special design with two part of force for arc chute to make the arc weak until the system voltage is unable to maintain the arc any longer.
2) Oil Circuit breaker
This type is an effective for quenching the arc and providing an open break after current has dropped to zero.There is used standard transformer oil as a arc quenching medium.
There have two(2) design of oil circuit breaker such as live tank for low voltage and dead tank for high voltage.It have several improvement adding like separated chamber and oil seal to avoid oil leaking.It suitable for system voltage up to 362 kV.
3) Air-Blast circuit breaker
This type is one of innovation from oil circuit breaker concept design as a voltage increase.There capability depend on insulating quality and arc-quenching.
Basic design for air-blast circuit breaker is used of dry and clean compressed air injected into the contact compartment.
4) Vacuum circuit breakers
This type of breaker very familiar for high voltage switch gear for 11 kV until 32 kV system voltage and up to 3500 ampere rating.In other term for this breaker is vacuum-bottle interrupters.
There use a vacuum concept to extinguish the arc and combination design with high speed spring charge to reduce arc during open or closed the main contact.
There are typically made with specified metal enclosed or metal clad for more durability as a switch gear for distribution system.
5) Gas circuit breakers
This breaker used a sulfur hexa-fluoride (SF6) as a medium for arc extinguish and high value of insulating.These breaker normally can found at the outdoor distribution system and suitable for system voltage up to 800 kV and 4000 ampere for current rating.