These create a sealed entrance for the cables to make their way inside, and must be carefully weatherproofed. In some cases, sealants such as GRP weathering systems may be used, enabling a cable tray to penetrate a wall without ductwork or other protective structures. ld's most innovative and flexible cable and pipe transits. 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 additional protec eferred to support and protect numerous small. Our Raychem cable entry seals (CES) are water-tight, heat-shrinkable products providing long-term sealing for cable penetrations into panels, junction boxes and through bulkheads. Our heat-shrinkable CES are available with the molded area configured with one opening for a single wire or cable. Electrical cable tray wall penetration firestopping 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. us-trations without notice. All illustrations, descriptions and technical information included in this document are provided as indications and can cable trays are equivalent. A better alternative to link-type seals, the SLIPSIL Plugs utilize a proprietary self-compression design, and have no bolts, nuts or metallic parts that.