1. The cable tray system shall have reliable electrical connection and grounding (only for metal cable tray).
2. The following requirements shall be met when the cable bridge system is allowed to form the grounding trunk circuit. The connection resistance between the cable bridge ends shall be no more than 0.00033 ohm, and the grounding holes shall be cleaned of the insulation coating. In a direct grounding system at neutral point 1KV and below, the grounding of the device is connected to the neutral grounding of the system. The metal cross-sectional area of the cascade direction of the bridge should not be less than the specified value when installing the power supply switch.
3. When laying a grounding main line along the whole length of the cable tray, at least one point of the cable tray shall be reliably connected to the grounding main line.
4. For vibration sites, spring coil should be installed at the connection of grounding part.