Firestopping Requirements for Cable Trays and Wall/Slab Penetrations

1. Cable Tray Wall Penetration Firestopping

1. Electrical cable tray wall penetration firestopping

1. Scope: Firestopping for busway, cable trays, cables, and trunking passing through walls in enclosed electrical installations.

1. Photograph

Core Procedures

1. Where cables pass through shafts, walls, slabs, or enter electrical panels or cabinets, openings shall be tightly sealed with firestopping materials in accordance with design requirements.
2. Process flow: reserved openings → busway installation → distribution box positioning and installation → conduit installation → cable routing → grounding → waterproof step → firestopping.
3. Working conditions: floor and wall finishes in the electrical shaft completed, and shaft doors installed.
4. Sealing shall be tight and reliable, without visible cracks or voids. For large openings, install a fire-resistant backing plate before sealing.
5. Installation requirements:
   1. Layout and positioning must be reasonable to facilitate installation and maintenance.
   2. Choose appropriate fire protection materials, such as fire-rated board, firestop packs, firestop mastic, or fire-resistant mineral wool.
   3. Firestop packs should be placed in an orderly sequence. The gap area between firestop packs and cables should not exceed 1 cm2, and the packing thickness should be not less than 24 cm.
   4. All gaps inside and around metal trunking must be sealed tightly and be complete both internally and externally.
6. Cover plates should be square, of consistent suitable dimensions, painted evenly, and used to close the opening.

2. Firestopping at Slab Penetrations for Electrical Shafts

Scope: Firestopping for busway, cable trays, cables, and trunking where they pass through slabs in electrical shafts.

Photograph

Key Process Points

1. Where cables pass through shafts, walls, slabs, or enter electrical panels or cabinets, openings shall be tightly sealed with firestopping materials in accordance with design requirements.
2. An electrical shaft shall have a threshold. Cable trays and busways at floor level or at slab penetrations shall have a waterstop no less than 50 mm in height.
3. At slab penetrations, provide 20–30 mm of firestopping and install a fire-support plate at the top.
4. Sealing shall be tight and reliable, without visible cracks or voids. For large openings, install a fire-resistant backing plate before sealing.
5. Installation requirements:
   1. Layout and positioning must be reasonable to facilitate installation and maintenance.
   2. Choose appropriate fire protection materials, such as fire-rated board, firestop packs, firestop mastic, or fire-resistant mineral wool.
   3. Firestop packs should be placed in an orderly sequence. The gap area between firestop packs and cables should not exceed 1 cm2, and the packing thickness should be not less than 24 cm.
   4. All gaps inside and around metal trunking must be sealed tightly and be complete both internally and externally.
6. Cover plates should be square, of consistent suitable dimensions, painted evenly, and used to close the opening.