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. It also helps reduce the risk of. Cable Types: Only use conductors rated for open-air environments, such as Tray Rated (Type TC) or Metal-Clad (Type MC) cables. A rung spacing of 6 to 9 inches (150 to 230 mm) is preferable when the cable tray cont d for instrumentation and control applications that require additional protec eferred to support and protect numerous small. In practice, cable tray dimensions are a system of interrelated measurements —width, depth, length, and material thickness—that directly affect cable fill compliance, heat dissipation, structural loading, and long-term expandability. From an engineering standpoint, cable tray dimensions are not. Although NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the documents, nor does it independently test, evaluate, or verify the accuracy or completeness of any information or the soundness of any judgments contained in its. The B-Line series Cable Tray Manual was produced by our technical staff. The following pages address the 2014 National Electrical Code® requirements for cable tray systems as well as design.
