Question { HP, 45932 }

Explain the working principle of Vacuum circuit breaker and
Air circuit breaker

Answer

when fault occure contacts of C.B. open. At that time arc
produce between fixed and moving contact.

C.B. is required to extanguised that arc.

In vaccume C.B. contacts of C.B. placed in highly vacuumed
bottel (i.e there is on any gas or air). For continuty of
arc oxigen is required. There for arc will be vanished.

In air C.B. there is arc spliter to quanche and to
langthand the arc. Due to long length arc resistance
increased and there for flow of current. So that arc
extinguished.