Air Circuit Breaker
The type of circuit breaker, which operates in air (where air-blast as an arc quenching medium) at atmospheric pressure, is known to be an Air Circuit Breaker. Air circuit breaker has completely replaced by oil circuit breaker. In different countries, still it is a preferable choice to use an Air circuit breaker up to 15KV because, there is no chance of oil fire like in oil circuit breaker.
Advantages of Air-Blast Circuit Beaker(VCB)
- Air blast circuit breaker is a suitable option to use where frequent operation is required because of lesser arc energy
- The risk of fire is eliminated in the operation of Air blast circuit breaker.
- It is small in size, because of the growth of dielectric strength is so rapid (which final contact gap needed for arc extinction is very small).
- Speed of circuit breaker is much higher during operation of the air blast.
- Arc quenching is much faster
- The duration of the arc is same for all values of current.
- Stability of operation can be maintained and depends on speed operation of circuit breakers.
- It requires less maintenance.
Application and Uses of Air Circuit Breaker
- It is used for protection of plants
- It is used for common protection of electrical machines
- It used for protection of transformers, capacitors and generators.
- Air circuit breaker is also used in Electricity sharing system and NGD about 15kV
- Also used in Low as well as High voltage and Currents applications .
OIL CIRCUIT BREAKER
The oil circuit breaker is the one of the oldest type of circuit breakers. The operation of oil circuit breaker is quite simple
ADVANTAGES OF OIL CIRCUIT BREAKER (OCB)
As an Arc extinguishing medium oil has the following advantages:
1. Oil produces hydrogen during arching. The hydrogen helps extinguish the arc.
2. The oil provides insulation for the live exposed contacts from the earthed portions of the container
3. Oil provides insulation between the contacts after the arc has been extinguished
TYPES OF OCBS
It has two types namely BULK OIL CIRCUIT BREAKERS & MINIMUM OIL CIRCUIT BREAKERS with different ranges
MCCB is actually the need to understand MCB is clear to most of the users. MCB is for low current interruptions and has fixed current rating for trip. It will not trip at earth fault. It has low KA rating, it is suitable for simple over current application, less than 100 A and has low cost. MCCB (Molded case C.B) is for high current application normally above 100 A and also programmable/adjustable for earth fault , over/under voltage protections etc. It has high KA ratings, hence costly.
EB METERING PANEL BOARD
EB Metering panels are to be installed in EB power supply input point at the resident of site lead has to be taken after the EB meter from this panel.