Clearances: Maintain at least 12 inches of vertical clearance above trays for installation and maintenance access (2026 NEC update). When installing two cable trays in parallel at the same height, the distance between them should be no less than 0. Grounding: Metallic trays can serve as equipment grounding. The NEC requires that cable trays must be supported by members at an interval specified by the cable tray manufacturer, but not more than 5 feet for horizontal runs to support the weight of the cables and other loads. The NEC has a requirement for ladder-type cable trays.