This installation guide provides comprehensive instructions for the assembly, cutting, and installation of the Trough (P31) cable tray system. The Cable Tray ng standards, performance standards, test standards and application in this document have been tested extens ompetent professional en completely installed, without damage either to conductors or. ngs, etc. Structural building members should never be cut, and cable trays should not be installed in hoist way or where subject to physical. Legrand continues to be an innovator in cable management solutions and is proud to introduce Cablofil Trough Tray, a cable management system designed to maximize network reliability and minimize lifecyle costs.