Installation of Finnish stepped cable trays

Finnish stepped cable trays should be installed with proper support spacing, alignment, and material selection to ensure safety, mechanical stability, and compliance with standards.

Material Selection

Choose the tray material based on the environment: painted or galvanized steel for indoor use, hot-dip galvanized or stainless steel for outdoor applications, and aluminum or fiberglass-reinforced plastic for corrosive or high-humidity areas. Ensure the tray's mechanical strength matches the weight and number of cables to prevent deformation or failure under full load .

Layout and Routing

• Align with building structure to avoid unnecessary crossings or detours .
• Shortest and straightest path is preferred to reduce cable loss and simplify maintenance .
• Segregate power and signal cables using separate trays to minimize electromagnetic interference .
• Maintain horizontal deviation ≤2mm per meter and vertical deviation ≤3mm per meter to ensure level and plumb installation .

Support and Spacing

• Establish the required elevation from the floor to the bottom of the tray using a laser or nylon string .
• Supports should provide sufficient strength for the tray's working load and be spaced according to manufacturer recommendations, typically maximum 600mm from bends or outputs .
• Use wall brackets, suspended supports, or center suspensions to secure trays to ceilings, walls, or steel structures .

Bends and Accessories

• Use horizontal or vertical bends, T-pieces, crossovers, and reductions to change routing direction or dimensions .
• Ensure the bending radius of accessories is equal to or greater than the minimum bending radius of the largest cable in the tray .
• Install splice plate connectors at approximately ¼ of the gap length between supports, avoiding midpoints or directly above supports .

Safety and Maintenance

• Do not use cable trays as walkways or ladders to prevent injury and damage .
• Ensure electrical continuity every 18 meters and proper grounding.
• Leave at least 300mm clearance above or between trays for cable installation and maintenance .
• Personnel should be trained in safe handling, lifting, and installation practices, including the use of gloves and steel-toed footwear during unloading and assembly .

Fireproofing and Compliance

• Follow IEC 61537 and local electrical standards for tray systems .
• Consider fireproofing measures and separation of high-voltage and low-voltage cables to maintain system reliability and safety . By following these guidelines, Finnish stepped cable trays can be installed safely, efficiently, and in compliance with technical standards, ensuring long-term reliability and ease of maintenance.