A common method is to use cable trays, which are installed on the ceiling and act as open structures to accommodate cables. These routes allow for organised routing over longer distances and offer flexibility for adjustments. 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. 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. This document deals with cables trays, cables and connector installation and segregation, cable trays earthing and E. For projects that are not 100 percent defined before design start, the cost of and time used in coping with continuous changes during the engineering and drafting design phases will be substantially less for cable tray wiring.