If an EGC cable is installed in or on a cable tray, it should be bonded to each or alternate cable tray sections via grounding clamps (this is not required by the NEC® but it is a desirable practice). Cable tray may be used as the Equipment Grounding Conductor (EGC) in any installation where qualified persons will service the installed cable tray system. These systems provide an efficient and adaptable solution for managing a wide range of cables, including power cables, control. The following pages address the 2014 National Electrical Code® requirements for cable tray systems as well as design solutions from practical experience. Why is bonding important in cable tray systems? Bonding ensures electrical continuity between all parts of the cable tray system, preventing. that system to lose its UL Classification.