ZHW-126 plug and switch system, also known as composite insulated combined electrical apparatus or half gas insulated switchgear, integrates components such as circuit breakers, disconnecting switches, grounding switches, built-in current transformers (with external current transformers being busbar-piercing type), and incoming and outgoing line bushings into a grounded metal enclosure. This assembly is filled with SF₆ gas at a certain pressure, serving as both the insulating and arc-quenching medium. The product features a three-phase separate tank structure. It is suitable for three-phase AC 50Hz power systems with rated voltages of 72.5 to 126kV, capable of breaking and closing load currents and short-circuit currents of power lines. It performs functions such as power line liaison, switching, control, measurement, system regulation, and safe isolation during line and equipment maintenance.