Why is MV switch-fuse so well adapted to public distribution applications?

In MV ring network configuration, the typical MV switchgear of the MV/LV substation specified by the utilities is a compact and often non extensible 3 functions switchgear RMU consisting in two load-break switch units plus one protection unit connected to the MV/LV transformer. The protection unit may be a switch-fuse combination or a circuit-breaker. For such public distribution applications, protection of MV/LV transformers by MV switch-fuse combination offers an optimized solution.