Summary: The key to grounding metal trays lies in "starting with 2 points, adding one every 20-30 meters, using 2 anti-loose bolts for galvanized trays, and crossing 4mm² copper wire for non-galvanized trays". Strict implementation can ensure personal and equipment safety. Cable tray may be used as the Equipment Grounding Conductor (EGC) in any installation where qualified persons will service the installed cable tray system. The metal in cable trays may be used as the EGC as per the limitations. Wire mesh cable trays are widely used in commercial offices, industrial facilities, data centers, and smart building infrastructure because they provide unmatched flexibility, excellent airflow, and fast, adaptable installation. If you take what UL states literally, ANY cut to tray (ladder or wi e) would cause a loss of UL Classification.
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