Support spacing for cable trays must align with the manufacturer's instructions, as outlined in NEC 392. Generally, standard trays require supports every 6 to 10 feet, while heavy-duty, long-span trays can handle distances of up to 20 feet between supports. For runs at an angle of 30 Degrees or less from the vertical, the vertical spacing is applicable. Note: At the point of change from vertical to horizontal and horizontal to. This publication is intended as a practical guide for the proper and safe* installation of cable ladder systems, cable tray systems, channel support systems and associated supports. Cable ladder systems and cable tray systems shall be manufactured in accordance with BS EN 61537, channel support. The spacing between trays, whether horizontal or vertical, depends on various factors like cable type, environment, and tray material. This article provides an in-depth. cable trays are equivalent. screw tie) is used to external fastening element fasten support elements to supporting parts of the build-ing structure and, in the sense of the standard, is not a part of the cable support system and is thus. Thanks Zanoter4, but my query is regarding the interval spacing of supports on vertically mounted straight section of cable trays. Would anybody agree? A cable riser usually is.