Step-by-step on-site guide: learn how to plan, mark, support, and install cable trays correctly, from shop drawing approval to final checks. us/ The Practical Skills Series: Cable Tray How to Install TRAYCAB Cable Trays How to fabricate a swept 90 degree bend in cable tray. Plan the Route Before You Drill No installation should start without a plan. en completely installed, without damage either to conductors or structural system use 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. This is why proper planning and execution are.