Choose a suitable location for the cable tray and measure dimensions for accurate sizing. Plan cable routes carefully, using ties or Velcro straps to prevent clutter and tangling. Cable tray manufacturing involves creating trays that are designed to hold, support, and protect electrical cables in various environments. Understanding the. The right cable tray sizing calculator helps engineers turn cable schedules into a verified tray width and fill check before material ordering and site installation. I have tried to explain them below. The first one is when you know the angle you want to create and the second is. The purpose of this article is to define the sequence and methodology for the installation of electrical cable trays, cable trunking, cable raceways and boxes, junction and pull boxes.