1. Cable tray systems must ensure reliable electrical continuity and be grounded (applicable only to metal cable trays).
2. When the cable tray system is permitted to serve as a grounding main circuit, the following requirements must be met: the connection resistance between cable tray sections shall not exceed 0.00033 ohms, and insulating coatings must be removed from grounding connection points. In systems with a voltage of 1 kV or less and a directly grounded neutral point, the grounding of powered equipment is connected to the system's neutral grounding. When automatic power-cutoff devices are installed, the longitudinal metal cross-sectional area of the cable tray must be no less than the specified value.
3. When a separate grounding main line is installed along the entire length of the cable tray, each section of the cable tray (including non-straight sections) must have at least one point reliably connected to the grounding main line.
4. In locations subject to vibration, spring washers must be installed at grounding connection points.
