Provides technical requirements concerning the construction, testing, and performance of metal cable tray systems. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned. FireMaster® products insulate cable trays carrying instrument control cables to ensure that the cables can operate long enough to allow process shut down during fires. The FireMaster® cable tray wrap consists of. The following charts give the number of 3M pillows needed to completely firestop an opening that cable tray passes through. UL Listed Systems Concrete Wall - C-AJ-4056 3 HR F-Rating, 3/4 HR T-Rating Gypsum. maintain spacing or to keep cables in place when the tray is ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. A rung spacing of 6 to 9 inches (150 to 230 mm) is preferable when the cable tray cont d for instrumentation and control applications that require. ucts; however, as an alternative DIN 4102-12 can be used. This is a test for electric cable systems that are required to maintain circuit integrity, so is therefore written around and is dependent on the cables themselves, but containmen of 90 minutes (the maximum time covered by DIN 4102-12). Cable tray installation must comply with specific technical standards to ensure electrical safety, system reliability, and long-term maintainability.