The cable tray is about 2-feet wide and the sprinklers are standard uprights. Route. association representing the major electrical equipment manufac-turers in the U. 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. 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. A properly designed and installed cable tray system will provide. Safety of a cable tray is not a matter of compliance with codes, but a matter of saving human life and billions of dollars' worth of infrastructure. Poorly fitted trays may serve as a fuse in case of a short or a top chimney in case of a fire.