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. Cable ladder systems and cable tray systems shall be manufactured in accordance with BS EN 61537, channel support. maintain spacing or to keep cables in place when the tray is ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. Fittings can, on the one hand, be used for horizontal or vertical changing of the routing direction or, on the other, to change the height or width of the. Although BS 7671 touches on the subject of cable supports, it does not detail specifically what these support distances should be. For licensed electricians, mastering these principles is essential.
[PDF Version]