A group of the main bus repair or failure does not affect the loop powered

Each line or main transformer circuit breaker using two groups were the main bus access main electrical wiring. Its advantages are high reliability, a group of the main bus  mcb circuit breaker  or failure does not affect the circuit power supply; either a circuit breaker repair or failure, it can be connected in parallel with another  electric meter  continues to supply. The disadvantage is that the circuit breaker in larger quantities larger investment.