Sectionalizing the buses offers added advantage. One section can be completely shut-down for maintenance and repairs, while the other continue to supply.
Secondly, by adding a current limiting reactor between the sections, the fault MVA can be reduced, thereby circuit-breaker of lesser capacity may be permitted.
Ring bus :
Ring bus provides greater flexibility. The supply can be taken from one adjacent section. The effect or fault in one section is localized to that section alone. The other section continues to operate.
Another method of economic use of circuit breaker in a substation is mesh arrangement .
In mesh arrangement, the CBs are installed in the mesh formed by the buses.
The circuits are tapped from the node points of the mesh. circuit breakers are utilized to control eight circuits, In the event of a fault on any circuit, 2 CB have to open, resulting in opening of the mesh.
