For large vertical shafts (Electrical Shafts / Risers) that run from the basement to the top floor, a special fire-rated powder compound (Fire Mortar) is used. It's mixed with water, trowelled (or poured) onto the floor of each storey around the cables descending into. Scope: Firestopping for busway, cable trays, cables, and trunking passing through walls in enclosed electrical installations. Where cables pass through shafts, walls, slabs, or enter electrical panels or cabinets, openings shall be tightly sealed with firestopping materials in accordance with. in the EC safety data sheets. The Promat construction are partly system protected. In regard to the guarantee our general sales conditions shall apply. All drawings and illu trations remain. 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. Cable tray installation must comply with specific technical standards to ensure electrical safety, system reliability, and long-term maintainability. Route. cable trays are equivalent. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned in this technical guide only apply to our own cable management ranges and cannot under any circumstances be transposed to si osure, overheating or. 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.