Power circuit grounding of cable trays is explained in CTI Technical Bulletins, Titles No. 8, 11, and 12, and the National Electrical Code Sections 318-3-© and 318-7. It is also covered in NEMA Standard VE-2. Cable tray may be used as the Equipment Grounding Conductor (EGC) in any installation where qualified persons will service the installed cable tray system. Tray fill limits must be calculated properly. Power and data cables require proper separation. Understanding NEC Article 392: Cable. Cable tray grounding is an indispensable aspect of electrical installations that plays a pivotal role in ensuring safety, reliability, and efficiency. Some international standards refer to grounding as earthing. For example, when a straight section of tray is cut to length and used in conjunction with a factory fitting — this installation would also. Grounding systems of independent systems between which voltages that could be dangerous to people may arise must be connected to each other conductively or with open groundings for potential equalization.