Lay grounding main lines (such as 40×4 galvanized flat steel or bare copper wire) along the entire length, with at least one point in each section (including non-straight sections) reliably connected to the main line. Interlayer bridging: The top layer and the lower layer of the cable tray are. Cable tray may be used as the Equipment Grounding Conductor (EGC) in any installation where qualified persons will service the installed cable tray system. There is no restriction as to where the cable tray system is installed. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned. Copper stranded wire, galvanized flat steel, or metal components used to install supports along the cable trays can serve as the main grounding conductor. Total length ≤ 30 m: ≥ 2 grounding points (one at each end).