A power transmission/reception line circuit breaker includes a vertical-type first circuit breaker tank and a plurality of branch lead-out ports arranged at an interval H. A busbar-side device is connected to each branch lead-out port other than an uppermost branch lead-out port to which a line-side device is connected and a busbar. A busbar link line circuit breaker includes a vertical-type second circuit breaker tank having a length shorter than that of the first circuit breaker tank by the interval H and a plurality of branch lead-out ports arranged at the interval H. A busbar-side device is connected to each of the branch lead-out ports.