Electrical and telecommunication wires with short to intermediate support span 5 to 12 feet are usually installed on this type of trays. It has all the standard widths that ladder trays have and as it is non ventilated it is used for less heat genarating purposes. Their open rung structure allows air circulation and simplifies large power cable installation. Its Compact size makes it easier to position around and connect to equipment. Channel Cable Tray is available in. Trays shall be supported at a maximum span of 2. See sizing cable tray page A21.