Fireproof or galvanized high-voltage cable trays

For high-voltage cable trays, fire-resistant trays are recommended in high-risk environments, while galvanized trays are suitable primarily for corrosion protection in low-risk areas.

Galvanized Cable Trays

Galvanized steel trays are coated with zinc to protect against corrosion. This can be achieved through electro-galvanization or hot-dip galvanization, providing sacrificial protection where the zinc corrodes instead of the steel . Galvanized trays are ideal for indoor environments or outdoor areas with moderate exposure to moisture, as they prevent rust and extend the lifespan of the tray system. However, zinc coatings have limited fire resistance, as zinc melts at relatively low temperatures, which can compromise the tray during a fire .

Fire-Resistant Cable Trays

Fire-resistant trays are specifically designed to maintain structural integrity and prevent fire spread in high-risk environments such as hospitals, high-rise buildings, and industrial facilities . These trays are often steel trays with fire-resistant coatings or specialized fireproof systems like Cablofil, which have been tested according to stringent standards such as DIN 4102-12, withstanding temperatures up to 1000°C for 30–90 minutes . Fire-resistant trays ensure that high-voltage cables remain operational during emergencies, which is critical for safety and continuity of service.

Material Selection Guidelines

• Indoor, low-risk environments: Painted or galvanized steel trays are generally sufficient for corrosion protection .
• Outdoor or high-humidity environments: Hot-dip galvanized or stainless steel trays provide better corrosion resistance .
• High fire-risk areas: Fire-coated steel trays or certified fireproof systems are strongly recommended to prevent fire propagation and maintain cable integrity .
• Aluminum trays: Lightweight and corrosion-resistant but not suitable for fire-sensitive applications due to low melting point and high thermal conductivity .

Conclusion

While galvanized trays are effective for corrosion protection, they do not provide adequate fire resistance for high-voltage installations in critical or high-risk areas. For environments where fire safety is a priority, fire-resistant cable trays are the preferred choice, ensuring both structural integrity and operational continuity during a fire. In practice, the selection should consider both environmental conditions and fire risk, sometimes combining galvanized steel for corrosion protection with a fire-resistant coating for enhanced safety.