Low-voltage power distribution cabinet refers to the complete set of power distribution equipment used to receive and distribute electric energy in the power grid with a voltage of 1000V and below. Low-voltage power distribution cabinet is a complete set of power distribution equipment that installs switching appliances, measuring instruments, protection devices and auxiliary equipment in low-voltage circuits in metal cabinets according to certain wiring schemes to receive and distribute electric energy. It is used in power supply and distribution points below 1000V. Generally speaking, there are two categories of low-voltage power distribution cabinets: fixed low-voltage power distribution cabinets and drawer-type low-voltage switchgear.

Among them, the most common fixed low-voltage distribution cabinets are PGL and GGD, and the drawer-type low-voltage switch cabinets are MNS, GCS and GCK.

Today, we focus on the GGD type fixed low voltage distribution cabinet.

GGD type fixed low-voltage distribution cabinet is a low-voltage distribution device with single-sided operation and double-sided maintenance. The meaning of its model is: G-AC low-voltage power distribution cabinet; G-fixed installation and wiring of electrical components; D-power cabinet.

The shape of GGD type low voltage distribution cabinet is shown in Figure 1. The cabinet frame is partially welded and assembled with 8MF cold-formed steel. The frame is provided with mounting holes, which can be adapted to the assembly of various components. The cabinet door adopts an integral single-door or asymmetric double-door structure, and the rear of the cabinet adopts a symmetrical double-door structure. Rubber sealing strips are added around the cabinet door to prevent direct collision with the cabinet body. The protection grade is IP30. The cabinet door adopts galvanized rotary hinge and frame necklace, which is convenient to install and disassemble. There is a small door on the upper part of the cabinet body for installing various instruments, indicator lights, control switches, etc. The lower part, the rear upper part and the top of the cabinet body have different numbers of heat dissipation slot holes. When the electrical components in the cabinet heat up, the number increases, it is discharged through the upper slot hole, and cold air is continuously added into the cabinet through the lower slot hole, so that the sealed cabinet body forms a natural ventilation duct from bottom to top to achieve the purpose of heat dissipation. The main bus bar is arranged at the rear of the upper part of the cabinet. The ZMJ bus bar clamp is thermoformed with high resistance thermal alloy material, with high mechanical strength and good insulation performance. The long-term allowable temperature can reach 120 ℃, and is designed into a building block combination, it is very convenient to install and use. The operating mechanism of the knife switch is a universal joint type rotating mechanism, the handle can be disassembled, the operation direction is left and right rotation, the operation is convenient, and the safety is enhanced. The components of the power distribution cabinet are designed according to the module principle, the external dimensions and opening dimensions are changed according to the basic modulus E = 20mm, and the installation parts in the cabinet are galvanized and antirust passivated. The installation parts in the cabinet frame are connected by grounding knurled screws, A complete grounding protection circuit is formed; the cabinet body is sprayed with polyester orange baking paint to eliminate glare and strengthen adhesion.

GGD AC low-voltage distribution cabinet has the characteristics of high segmentation capacity, good dynamic and thermal stability, flexible electrical scheme, convenient combination and high protection level. GGD type distribution cabinet according to the size of its breaking capacity can be divided into I, II, III type, the maximum breaking capacity of 15, 30, 50kA. The main circuit design scheme has 126 kinds, can meet the needs of all aspects.