Requirements for fireproof partitions for cable trays

Fireproof partitions on cable trays must use appropriate fire-resistant materials, be properly spaced, and installed to fully seal gaps to prevent fire spread while maintaining accessibility and compliance with standards.

Purpose of Fireproof Partitions

Fireproof partitions, also called fire-blocking sections or fire sections, are installed on cable trays to isolate fires, prevent fire propagation, and protect power systems and personnel. They are particularly critical in high-risk environments such as power plants, industrial facilities, and electrical control rooms, where equipment aging or external fire sources can trigger fires .

Material Selection

The choice of fireproof materials depends on environmental conditions and installation requirements:

• Fireproof boards: Provide high fire resistance but may be heavy and occupy space .
• Fireproof coatings and mud: Offer easy application and good heat resistance, suitable for retrofits .
• Fireproof bags or packs: Convenient for installation, effective for small gaps .
• Intumescent caulks and putty: Expand under heat to seal gaps, ideal for irregular openings .
• Lightweight fireproof sections: Easy to install and maintain, with good heat dissipation . Materials should be stable under water exposure, rodent damage, and mechanical stress.

Installation Requirements

1. Spacing and Segmentation: Fire partitions should be installed at regular intervals along the cable tray, typically at points where fire spread risk is highest, such as near control rooms, distribution devices, or wall penetrations .
2. Sealing Gaps: All gaps between the cable tray and partition must be tightly sealed. For firestop packs, the gap should not exceed 1 cm², and packing thickness should be at least 24 cm .
3. Backing Plates: For large openings, a fire-resistant backing plate should be installed before sealing to ensure stability and complete fire containment .
4. Alignment and Accessibility: Partitions must be aligned with cable tray layout to avoid obstructing maintenance or cable routing .
5. UL and Fire Ratings: Use UL-listed firestop systems or materials with appropriate F-Rating and T-Rating for walls, slabs, or penetrations. For example, concrete walls may require a 3-hour F-rating, while gypsum walls may require 1–2 hours .
6. Covers and Plates: Cover plates should be square, evenly painted, and securely fixed to close openings completely .

Maintenance and Inspection

• Regularly inspect partitions for damage, gaps, or deterioration.
• Reapply coatings or replace firestop packs as needed to maintain fireproof integrity.
• Ensure that any modifications to cable trays or added cables do not compromise the fire-blocking sections .

Summary

Installing fireproof partitions on cable trays involves selecting suitable fire-resistant materials, proper spacing, complete sealing of gaps, and compliance with fire ratings and standards. Correct installation ensures fire containment, operational safety, and regulatory compliance, while facilitating maintenance and long-term reliability of the cable tray system .