It works high voltage switches and circuit breakers similar. General interrupter device equipped with a simple, but its structure is relatively simple. The picture shows a puffer type high-voltage load switch, their work is: When opening, in opening action of the spring, the spindle is rotated clockwise, on the one hand by the slider-crank mechanism so that the piston moves upward, the gas compression; another Transmission system via two four-bar linkage consisting of the main knife to open, and then push the knife so that the arc interrupter contacts open, the cylinder of compressed air to blow out the arc through the nozzle. Closing, through the spindle and drive system, the main knife and arc knife while turning it clockwise first arc contact closure; spindle continues to rotate, then close the main contacts. In the closing process, while the opening spring energy storage. Since breaking load switch can not short-circuit current, so often the limiting high-voltage fuse used in combination, the use of current-limiting fuses current limiting, not only to complete the task of breaking the circuit and can significantly reduce the short-circuit current caused by heat and electric power. Counters in the home, called metal armored away switching equipment in the home. Belong to high voltage electrical installations, the maximum operating voltage of 3.6 / 7.2 / 12kV, three-phase AC 50Hz single busbar in the system or dual-bus sub-system indoor power distribution equipment. For receiving power and network with 3.6-12kV of, and exercise control power circuit protection, monitoring and measurement. The home switch cabinet is mainly used by power plants, small and medium generator power transmission, power system of secondary substations, transmission, and distribution of industrial and mining enterprises, as well as large high-voltage motor starter and so on. Drawer storey modulus of 160mm, unit circuit rated current of 400A and a lower per MCC cabinet drawer drawers can be installed up to 11 units of a drawer or 22 half unit into the outlet according to the size of the current number of pieces with different piece structure with the specifications of connector