Cable trays are used for equipment grounding

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 metal in cable trays may be used as the EGC as per the limitations. Cable tray wiring systems have excellent safety and dependability records. If you take what UL states literally, ANY cut to tray (ladder or wi e) would cause a loss of UL Classification. For example, when a straight section of tray is cut to length and used in conjunction with a factory fitting — this installation would also. An Equipment Grounding Conductor (EGC) refers to a safety wire or a metal conductor that transfers the so-called stray electricity back to the power source in case of a problem. Consider it as an emergency electricity exit. Grounding: Metallic trays can serve as equipment grounding conductors (EGC) if they meet NEC requirements. Fill Limits: For power cables, the fill must not exceed 40% of the tray's. [PDF]