Cable sag results from incorrect spacing of cable tray supports or from employing the incorrect tray type that is, light-duty perforated trays in high-load applications. Complicating the problem are overloaded trays and large unsupported spans. Where cables pass through shafts, walls, slabs, or enter electrical panels or cabinets, openings shall be tightly sealed with firestopping materials in accordance with. Cable tray failures can cause operational disruptions, equipment damage, and safety risks. This guide discusses common cable tray problems, from loosening and corrosion to grounding issues and installation errors, along. 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. It was as if a different person planned and executed each and every hole — even in the same building, even on the same floor! There.