What do you know about cabinets?

At present, the common grounding scheme of integrated wiring system is to establish independent weak current grounding conductors in weak current machine room, weak current machine room and telecom machine room, and ground them together with other grounding conductors on the general grounding pile of the building to form a joint grounding body in the building. In the same cabinet, there are often several or even dozens of shielded distribution frames, which should be grounded in a star structure. The grounding of shielded distribution frame should be directly connected to the grounding copper bar of the cabinet, forming a star grounding in the cabinet. It is suggested to use a mesh grounding wire larger than 6mm2 as its grounding wire in order to improve the high frequency characteristics of the cable by using its large surface area. In order to prevent short circuit of mesh grounding wire, plastic hose should be sleeved outside the grounding wire.

The early shielded distribution frame used the front column in the cabinet as the bus bar. Because this method will be affected by the quality of the cabinet and may cause grounding connection failure, it is rare to see such a distribution frame now. In the telecom room, if there are multiple cabinets, their grounding wires should also be connected to the grounding piles in the telecom room in a star structure. This form of grounding requires buildings to have as many good grounding points as possible. For buildings that cannot meet this requirement, honeycomb structure is used to make up for it. This kind of local grounding network can be imitated by metal cable channel, double floor or parallel copper wire. Adding grounding wire can reduce the structural size of grounding circuit and weaken the influence of interference signal. However, the design of this prevention and control structure should be combined with high-pressure regulations and safety schemes. Each cabinet shall be connected to the grounding copper bar of the machine room through the grounding wire, and ensure that the grounding resistance of the distribution frame to the ground is less than 1ω. The grounding of the shielded wiring system should be completely separated from the high voltage grounding and connected to the grounding bus at the bottom of the building.