179 (J) covers the listing and marking of Class 2, Class 3, and Power Limited Tray Cable (PLTC) cables and describes their intended use: A cable marked CL2 indicates that the cable is for Class 2 applications. to join two components together, clamp or fix to walls, ceilings or other supports, covers and cable retainers Used within an electrical installation to restrain cables in a manner that can withstand the forces they generate, including those. cable trays are equivalent. 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. A cable tray is a metal or non-metal structure used to lay electrical cables and wires, serving to support, protect, and guide the cables. What is the role of a cable tray in electrical engineering? A cable tray allows for the neat and aesthetic arrangement of cables, improves the reliability. NEC Table 725. 179 (J) provides cable descriptions. These guidelines are not intended to cover all details or variations in cable ladder and cable tray.