How to seal cable tray openings

Sealing a cable tray opening can be achieved using fireproof pillows, cable entry seals, grommets, compression seals, or heat-shrink materials, depending on environmental and safety requirements.

Fireproof Sealing

For fire safety, intumescent fireproof pillows like AF BAGS are commonly used. These are certified under EN 1366-3 and can seal cable tray penetrations up to EI 240. They consist of a non-combustible fiberglass casing filled with intumescent compounds and thermal insulators. To use them, measure the cable tray dimensions, select the appropriate size and number of pillows, and insert them into the opening. They are repositionable, making maintenance or modifications easier, and provide effective fire containment for cables up to 21 mm in diameter .

Cable Entry Seals

Cable entry seals create a watertight and dustproof barrier around cables. They come in several types:

• Grommet seals: Flexible rubber-like seals for dynamic environments where cables may move .
• Compression seals: Use mechanical pressure to tightly seal cables, ideal for industrial or outdoor applications .
• Multi-cable entry seals: Allow multiple cables to pass through a single opening while maintaining individual seals .
• Heat-shrink seals: Shrink when heated to form a tight seal around the cable, providing both electrical and environmental protection . When selecting a seal, consider the cable diameter, tray opening size, material compatibility, and the required IP rating (IP67 or IP68 for waterproof and dustproof protection).

Installation Best Practices

1. Clean the surface: Ensure the cable tray and surrounding area are free of dust, debris, or moisture to ensure a solid seal .
2. Follow manufacturer instructions: Each seal type may have specific installation steps, including compression torque or heat application .
3. Test the seal: After installation, check for leaks or gaps by exposing the seal to water or pressure, depending on the environment .
4. Use additional sealants if needed: Non-conductive putty or caulking can enhance protection against moisture, dust, and gases .

Additional Considerations

• For fire-rated installations, ensure the sealing product is certified for the required fire resistance.
• For outdoor or corrosive environments, choose materials like silicone, rubber, or stainless steel for durability .
• For high-density cable trays, multi-cable entry seals or modular plates can simplify installation and reduce the number of penetrations . By combining the appropriate seal type with proper installation techniques, you can effectively protect cable tray openings from fire, moisture, dust, and other environmental hazards while maintaining system safety and compliance.