Where cable tray systems contain only signal and communication circuits that operate at low energy levels, power grounding per NEC Section 318-7 is not appropriate, but cable tray grounding for lightning protection, noise, and electromagnetic interference is necessary. Cable tray grounding is an indispensable aspect of electrical installations that plays a pivotal role in ensuring safety, reliability, and efficiency. It involves connecting cable trays to the facility's grounding system, providing a low-impedance path for fault currents and protecting personnel. 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. 8, 11, and 12, and the National Electrical Code Sections 318-3-© and 318-7. If you take what UL states literally, ANY cut to tray (ladder or wi e) would cause a loss of UL Classification.
