Galvanized flat steel is laid on the outside of the cable tray

Galvanized flat steel is applied to cable trays to provide corrosion resistance, mechanical protection, and long-term durability, especially in outdoor or harsh environments.

Purpose and Benefits

Galvanized flat steel serves as a protective layer for cable trays, shielding the underlying steel from rust and oxidation. The zinc coating acts as a sacrificial barrier, preventing corrosion even if the surface is scratched or dented. This makes galvanized trays suitable for outdoor installations, industrial plants, and areas with high humidity or airborne chemicals . Properly produced hot-dip galvanized trays can last 25–50 years, depending on environmental conditions and maintenance .

Galvanization Processes

There are two main galvanization methods for cable trays:

1. Electro-galvanization: Deposits a thin, uniform zinc layer via electrolysis. It provides moderate corrosion resistance and is generally used in less harsh environments .
2. Hot-dip galvanization: Submerges steel in molten zinc, forming a thick zinc-iron alloy layer with excellent adhesion. This method offers superior corrosion protection and is preferred for outdoor, coastal, or industrial applications .

Coating Standards and Thickness

For hot-dip galvanized trays, the zinc coating thickness is critical for durability. Industry standards recommend a minimum coating mass of 275 g/m², corresponding to a zinc layer of approximately 39 µm, to ensure effective corrosion resistance during transit and storage, particularly in marine or coastal environments . The tray sheet metal typically ranges from 1.5 mm to 3 mm in thickness, providing sufficient mechanical strength for cable support .

Installation Considerations

When installing galvanized cable trays:

• Ensure mechanical strength is adequate to prevent deformation under full load .
• Maintain level, plumb, and securely mounted trays with proper splice plates and bolts .
• Use grounding jumpers at each connection to ensure electrical continuity .
• Remove sharp edges or debris to prevent cable damage .
• For outdoor or corrosive environments, hot-dip galvanized or stainless steel trays are recommended .

Summary

Applying galvanized flat steel to cable trays enhances corrosion resistance, structural integrity, and service life, making it a reliable choice for both indoor and outdoor electrical installations. Hot-dip galvanization is the preferred method for harsh environments, and adherence to coating thickness standards ensures long-term performance .