It is necessary to group circuit br

It is necessary to group circuit breakers and relays into two systems facing in opposite directions, each circuit breaker being at the start of a section, considered in the direction of its own grading system. In fact the arrangement may be regarded as the equivalent of two radial feeders fed, respectively, from either supply point, the two 'component feeders' being superimposed in the actual line (see Fig. 8.4B).