According to the National Electrical Code standard of the United States, a cable tray is a unit or assembly of units or sections and associated fittings forming a rigid structural system used to securely fasten or support cables and raceways. The cable trays consist of a thin metallic plate and electro-welded steel rods. 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. An Electrical cable tray is a type of a containment used to support insulated electrical cables used for power distribution, control, and communication.