Cable tray grounding is a very important task, and its requirements mainly include the following aspects:
1. The grounding resistance should meet the specified value: According to national standards, the grounding resistance of cable trays should be less than or equal to 4 ohms. The smaller the grounding resistance, the better the grounding effect, which helps to protect equipment and personnel safety.
2. The layout of the grounding grid should be reasonable: The grounding grid is a wire network that connects various grounding electrodes and should be evenly arranged in various parts of the cable tray to ensure good grounding effect. At the same time, the grounding network also needs to be reliably connected to the grounding system.
3. The selection of grounding electrodes should be appropriate: The selection of grounding electrodes should consider factors such as soil resistivity, soil moisture, and groundwater level. In general, the grounding electrode can use buried metal rods or buried conductors to ensure a good grounding connection with the ground.
4. The introduction of grounding cables should be reasonable: copper conductors should be used for grounding cables, and the cross-sectional area should be large enough to ensure low resistance conductivity. The introduction of cables should try to avoid mutual interference with other power lines, signal lines, etc.
5. The installation of grounding equipment should be firm and reliable: grounding equipment, including grounding electrodes, grounding grids, connecting wires, etc., should be firmly fixed and able to withstand external forces and environmental conditions, ensuring long-term stable and reliable grounding function.
In short, the requirement for cable tray grounding is to ensure the safety of equipment and personnel, and to reduce the occurrence of electrical accidents. When conducting grounding work, it is necessary to strictly follow relevant specifications and standards to ensure that the performance of the grounding system meets the design requirements.