Specifications for galvanized fireproof cable trays

Galvanized fire-resistant cable trays are steel-based systems with protective zinc coatings, designed to maintain circuit integrity under fire conditions for up to 90 minutes.

Material and Galvanization

Galvanized cable trays are typically made from steel, which is coated with zinc to enhance corrosion resistance. The galvanization can be pre-galvanized (electro-galvanized) or hot-dip galvanized, with the zinc layer providing sacrificial protection against corrosion. The thickness of the zinc coating directly affects the tray's durability in corrosive environments, and small scratches or cuts are protected by the formation of a zinc oxide or zinc carbonate patina over time . Stainless steel variants may include AISI 316L with chromium and molybdenum for enhanced corrosion resistance .

Fire Resistance

Fire-resistant cable trays are tested to maintain circuit integrity during fire exposure. Common standards include DIN 4102-12, BS EN, and UL 2196. These trays can sustain fire exposure for up to 90 minutes (E90 rating), ensuring that cables remain operational during critical fire events . The fire resistance is achieved through the tray design and the use of fire-retardant coatings or materials that prevent heat transfer to the cables.

Mechanical and Structural Specifications

Galvanized cable trays are available in ladder, perforated, and wire mesh configurations. Ladder-type trays feature two longitudinal side rails with transverse rungs, welded or bolted, providing high load-bearing capacity and compliance with NEMA VE 1 standards . They are offered in heavy-duty (Series 2–5) and light-duty (NEMA 12A/12B) options, suitable for different cable loads and spans . Components include splice plates, bolts, nuts, and washers for secure assembly.

Regulatory Compliance

These cable trays are UL-listed and NFPA 70 compliant, ensuring suitability for use as equipment grounding conductors and adherence to electrical safety codes . CE marking may also apply in European installations, indicating compliance with relevant EU directives . Third-party certifications, such as LCIE, IMQ, or UL, verify both mechanical and fire performance.

Installation Considerations

• Designed for field assembly with modular components.
• Can be mounted on walls, ceilings, or supports depending on load and environment.
• Must be used within specified voltage, current, and temperature limits to maintain warranty and performance .
• Fire-resistant trays should be installed with proper spacing and supports to ensure fire endurance and mechanical stability.

Summary

Galvanized fire-resistant cable trays combine steel strength, zinc corrosion protection, and fire endurance to provide a reliable solution for industrial and commercial electrical systems. They are available in multiple configurations, comply with UL/NFPA and international standards, and are capable of maintaining cable circuit integrity for up to 90 minutes under fire conditions .