Fireproof Galvanized Cable Tray Thickness Standard

The typical steel thickness for fireproof galvanized cable trays ranges from 1. 5 mm to 3 mm, with zinc coating of at least 45 µm for corrosion protection, and additional fireproof coatings applied for flame resistance.

Steel Thickness and Zinc Coating

For galvanized cable trays, the side plates and base plates usually range from 1. 5 mm to 3 mm in thickness, depending on the load and span requirements. Heavier components such as brackets or supports, often exceeding 3 mm, require higher zinc coating standards.

The minimum zinc coating thickness for hot-dip galvanized trays is generally 45 µm, corresponding to a coating mass of 325 g/m², ensuring adequate corrosion resistance. For electro-galvanized trays, standards like GB/T 26941. 1-2011 define similar requirements.

Fireproofing Measures

Fireproof galvanized trays are typically treated with fire-retardant coatings or flame-resistant paints to slow flame spread and increase heat resistance. Installation may include fire barriers within the tray to isolate different fire zones, and fire-rated penetration sealing when trays pass through walls or floors. These measures ensure that the tray maintains structural integrity and limits fire propagation in industrial or commercial environments.

Standards and Compliance

The IE

C 61537 standard provides guidelines for mechanical strength, corrosion resistance, and electrical continuity of metal cable trays, including galvanized steel. Compliance ensures that trays can safely support cable loads while maintaining durability and fire safety. Local regulations may also specify additional fireproofing or coating requirements depending on environmental conditions, such as high humidity or corrosive atmospheres.

Practical Recommendations

Select tray thickness based on cable weight, span, and mechanical load. Ensure zinc coating meets or exceeds 45 µm for standard trays; heavier components may require ≥55 µm. Apply fireproof coatings or use flame-retardant composite trays in high-risk areas.

Inspect regularly for corrosion, deformation, or damage to coatings to maintain fire resistance and structural integrity. By adhering to these thickness and coating standards, fireproof galvanized cable trays provide both mechanical support and enhanced fire safety for electrical installations.