Busbar protective relay

BUS BAR  

Bus bar is simply a set of conductors for different phases at same voltage with some incomings and outgoings circuits. The different types of bus bar schemes are as under.  1. Single bus bar, single breaker scheme. 2. Double bus bar, single breaker scheme.  3. One & half Circuit breaker scheme.  4. Ring bus bar scheme.  ----->SINGLE BUS BAR, SINGLE BREAKER SCHEME  In single bus bar for supply two isolator and one circuit breaker is used. It’s simplest scheme of supply. Continuity of supply is affected in case of Fault and maintenance. This scheme is used at unimportant grid stations.   ------> DOUBLE BUS BAR, SINGLE BREAKER SCHEME  In this scheme single circuit breaker and double bus bar is used, one is main bus bar, whereas, other is reserved bus bar. Normally main bus bar in circuit. In case of fault, repair or extension, reserve bus bar can be used. In this scheme any bus bar can be used as main bus bar, because the capacity of both is same.  -----> ONE &HALF CIRCUIT BREAKER SCHEME In this scheme three circuit breakers are used for the protection of two lines, therefore it is called one and half breaker scheme .it is reliable and flexible scheme. In this scheme any bus bar or circuit breaker can be spared for maintenance purpose without affecting the continuity of supply. This scheme is useful there, where two or more circuits exit.  ----> RING BUS BAR SCHEME In this scheme due to bus bar and circuit breaker having connected in series, adopt the shape of ring, therefore it is called Mesh Scheme or Ring Bus Bar. There is one circuit breaker for one circuit. These are arranged as that two breakers control every circuit. Both breakers trip in case of fault .for the repair of breaker the ring is opened, but the circuits work without failure of supply.