Sectionalized Single Busbar System
In this scheme, the main bus is sectionalized by a bus coupler breaker & two nos. isolators by which the main busbar can be done separately as when required. The shutdown of one portion of the busbar can be taken for any maintenance work purpose. It is shown in the below fig.
The advantage & disadvantage of sectionalized single bus system is given below:-
Advantage:
- The operation of this system is a simple as that of the single busbar system.
- Maintenance cost is low.
- For maintenance or repairing of the busbar, only one-half of the busbar is required to be de-energized, hence the possibility of a complete shutdown is thereby avoided.
- It is possible to utilize the busbar potential for the line relays.
Disadvantage:
- The main disadvantage, when a circuit breaker of any circuit of this system fails, power can not be given the said circuit until rectification of the circuit breaker.
- For regular maintenance work at busbar, one of half busbar is required to be de-energized, hence feeders & transformer of that portion will be kept in off condition.
- If at any stage, a circuit is required to be added to the existing system, half of the busbar is to be de-energized during the period the work is carried out.