△ Medium-voltage switchgear structure

The medium-voltage switchgear consists of two major parts: a fixed cabinet and a removable component (referred to as a trolley). The cabinet shell and the partitions of each functional unit are connected by bolts. The high-voltage switchgear shell has an IP43 protection level.

△ Medium-voltage switchgear shell and compartment

The shell and partition of the medium-voltage switchgear are made of imported aluminum-zinc steel plates processed by CNC machine tools and adopt multiple folding and overlapping processes, so that the entire cabinet not only has high precision, high mechanical strength, strong corrosion resistance and chlorination resistance, but also adopts multiple folding and overlapping processes to make the cabinet lighter and more mechanically strong than other welded cabinets of the same type. The cabinet adopts an assembled structure and is connected with rivet nuts and high-strength bolts. The switchgear is divided into a trolley room, a busbar room, a cable room and an instrument room (low-voltage room) by partitions, and each compartment and the shell are independently grounded. The switchgear door panel, rear sealing plate, and side screen adopt electrostatic powder spraying technology to improve their surface impact resistance and corrosion resistance, ensuring surface quality and beautiful appearance.

△ Trolley

The trolley frame is made of steel plate processed by CNC machine tools and then riveted. The trolley is insulated with the cabinet body, and the mechanical interlock is safe, reliable and flexible. Trolleys are divided into vacuum circuit breaker trolleys, transformer PT trolleys, metering trolleys, isolation trolleys, etc. according to their uses. The height, width and depth of various trolleys are unified, and trolleys of the same specifications can be interchanged. The trolleys have isolation, test and working positions in the switch cabinet. Each position is equipped with a positioning device to ensure reliable interlocking, and must be operated according to the "five-prevention" interlocking operation procedure. Various trolleys are pushed in or out with high-strength push-pull levers. The operation is light and flexible, suitable for on-duty personnel. When the trolley needs to be moved out of the switch cabinet, just press the trolley push-pull lever to the horizontal position, and the trolley push-pull lever becomes a trolley track for the trolley to slide. You only need to pull the trolley lightly to easily pull out the trolley for inspection and maintenance. The entire trolley is small in size and light in weight, making it extremely convenient to inspect and maintain.

△ Cart room

A guide rail is installed at the bottom of the cart room (the width of the guide rail is the same as the width of the cart push-pull lever) for the cart to slide from the disconnected position/test position to the working position in the cabinet. There is a metal shutter curtain plate in the cart room, which is installed on the upper and lower contact boxes of the cart room. When the cart moves from the isolation/test position to the working position, the metal shutter curtain plates on the upper and lower static contact boxes are automatically opened at the same time in conjunction with the cart. When the cart moves in the opposite direction, the metal shutter curtain plates automatically close until the cart retreats to a certain position and completely covers the static contact box, forming an effective isolation. Since the upper and lower metal shutter curtain plates can be operated separately, the metal shutter curtain plates on the live side can be locked during maintenance, thereby ensuring that the operator does not touch the live body. When the trolley is operated and powered on with the switch cabinet door closed, the position of the trolley in the cabinet can be seen through the observation window, and the ON/OFF mechanical position indicator on the trolley can also be seen. The cabinet door is equipped with ON (for closing the circuit breaker) and OFF (for opening the circuit breaker) buttons.