When solid bottom trough tray is installed outdoors, or indoors in humid locations, and EMI/RFI shielding protection is not required, it is recommended that 1⁄4”weep holes be drilled into the tray bottoms at the sides and in the middle every 3 feet to limit water. When solid bottom trough tray is installed outdoors, or indoors in humid locations, and EMI/RFI shielding protection is not required, it is recommended that 1⁄4”weep holes be drilled into the tray bottoms at the sides and in the middle every 3 feet to limit water. But before you lay the first tray or clamp down a single cable, you need a solid plan. This guide breaks down the process step by step. Plan the Route Before You Drill No installation should start without a plan. Mark the cable tray route based on your electrical cable tray design and site. When offloading tray from a flat deck trailer using an overhead crane, care should be exercised in the placement and length of the slings to prevent crushing the product (siderails). Only. Cable tray (or cable ladder) systems are a popular alternative to electrical conduit systems, as they have an outstanding record for dependable service, design flexibility and cost savings in commercial and industrial applications. The process described here takes a systematic approach to ensuring that cable tray installations meet safety, reliability, and project-specific needs while following to. Welcome to Engineerings.