Figure 9.9 Double busbar switching arrangement (after Fletcher [4, chap. 9])
Here:
• each circuit is provided with a dedicated circuit breaker CB (1) and
can be selected to connect to either of the two independent busbars
by appropriate switching of busbar selector disconnectors (2)
• the busbars can be coupled by means of a bus coupler circuit breaker
CB (3), the line disconnectors (4) being normally included at transmission
voltages to facilitate maintenance, but this feature may be
omitted in many cases, without loss of operational functionality
• service continuity can be maintained with a busbar out of service;
however, Fletcher points out that a single circuit outage is necessary
for fault repair or maintenance in the CB area