The KYN550 load switch-fuse combination electrical cabinet is an intelligent, environmentally friendly, compact, air-insulated high-voltage switchgear developed by our company.

　　Cabinet dimensions (W×D×H) 550mm×1400mm×2200mm, using a new 550 cabinet dedicated load switch-fuse combination electrical appliance, the combination electrical appliance design is unique and novel, fuse replacement is quick and convenient, widely used in industrial and mining enterprises, residential areas, hospitals, schools, substations and other power distribution systems, is a good choice for protecting transformers, arc suppression coils, and high-voltage motors.

■ Technical Parameters

Interlock device to prevent misoperation

　　The switchgear has a reliable interlock device to provide reliable safety protection for operators and maintenance personnel, such as:

　　(1) After the truck is moved from the working position to the isolation/test position, the movable curtain plate will separate the static contact box to prevent accidental entry into the energized compartment. During maintenance, the movable curtain plate can be locked with a padlock.

　　(2) When the circuit breaker is in the closed position, the truck cannot be pulled out from the working position or pushed from the isolation test position to the working position; the circuit breaker truck must be fully locked in the test position or working position before it can be operated.

　　(3) The grounding switch can only be operated when the truck is in the isolation/test position and outside the cabinet; when the grounding switch is in the closed position, the truck cannot be retracted from the isolation/test position to the working position.

　　(4) When the truck is in the working position, the secondary plug is locked and cannot be unplugged.

Pressure relief device

　　Pressure relief devices are installed above the truck chamber, busbar chamber, and cable chamber. When an internal fault arc occurs in the circuit breaker or busbar, accompanied by the appearance of the arc, the internal air pressure of the switchgear increases, and the pressure relief metal plate installed on the top will automatically open to release the pressure and exhaust gas to ensure the safety of the operators and the switchgear.

Interlock between secondary plug and truck position

　　The connection between the secondary wiring on the switchgear and the secondary wiring of the truck is achieved through a secondary plug. The moving contact of the secondary plug is connected to the truck through a nylon corrugated tube, and the secondary static contact seat is installed on the upper right of the circuit breaker compartment of the switchgear. The secondary plug can only be plugged in and unplugged when the truck is in the test isolation position. When the truck is in the working position, the secondary plug is locked due to the mechanical interlock and cannot be unplugged. The circuit breaker truck can only trip before the secondary plug is connected. Because the closing mechanism of the circuit breaker truck is electromagnetically locked, it cannot be closed.

Energized indication device

　　The switchgear is equipped with an energized indication device, which consists of a high-voltage sensor and a portable display. The sensor is installed on the busbar or feeder side, and the display interface is installed in the low-voltage compartment of the switchgear. When it is necessary to detect whether the three phases A, B, and C are energized, the plug of the portable display can be inserted into the L1, L2, and L3 interfaces. If the display works, it indicates that the busbar or feeder is energized; otherwise, it indicates that it is not energized. It can also be used as a phase sequence detector or an electro-optical indicator, and its function is also to detect whether the high-voltage side is energized.

Preventing condensation and corrosion

　　In order to prevent the danger caused by condensation in high-humidity or climates with large temperature changes, heaters are installed in the circuit breaker and cable compartments for use in such environments and to prevent corrosion.

Grounding device

　　A 5×40mm² grounding copper busbar is installed separately in the cable compartment, which can be connected to adjacent switchgears and is in good contact with the cabinet body. This grounding busbar is used for directly grounding components, and because the entire cabinet body is made of aluminum-zinc plated sheets, the entire cabinet body is in a good grounding state, ensuring the safety of operating personnel and the cabinet body.