Proper ladder-type cable tray installation involves careful planning, material handling, support setup, cutting, grounding, and inspection to ensure safety, compliance, and long-term reliability.

Planning and Pre-Installation

Before starting, review approved shop drawings to determine tray routes, lengths, and locations. Ensure the installation area is clean, free of debris, and civil works are completed. Coordinate routes with other services to avoid clashes and maintain a minimum clearance of 150 mm from mechanical or electrical systems for future maintenance and cable pulling .

Material Handling and Storage

• Inspect all received materials against approved submittals; reject damaged or non-compliant items .
• Store trays and ladders horizontally on flat surfaces with timber supports at 1-meter intervals, covered to protect from moisture and sunlight .
• Keep accessories organized and free from dust, oil, or corrosion .

Support Structure Installation

• Use threaded rods, 'L' angles, or slotted 'C' channels to support trays, maintaining a maximum distance of 1.2 meters between supports to prevent sagging .
• Provide additional supports at bends, branches, and offsets (typically 150–250 mm from fittings).
• Trapeze or swing-type hangers are commonly used for ceiling-mounted trays, ensuring proper alignment and load distribution .

Cutting and Fixing

• Cut trays and ladders to required lengths using appropriate tools (hack saw, jigsaw, or skill saw for aluminum) and remove burrs to prevent cable damage .
• Treat cut edges with zinc-rich paint to prevent corrosion.
• Fix trays neatly in straight lines, ensuring expansion provisions at building joints and fire-rated walls .

Grounding and Fire Safety

• Install copper earth links at every joint to maintain electrical continuity .
• Apply approved fire sealant where trays cross fire-rated walls or floors.
• Ensure all supports and fittings comply with manufacturer specifications and local electrical codes.

Cable Laying and Labeling

• Lay cables neatly using cable ties or straps, leaving slack for expansion and maintenance .
• Provide identification labels for power and ELV services.
• Install tray covers in areas exposed to sunlight or mechanical risk.

Inspection and Quality Control

• Conduct inspections after installation to verify alignment, support spacing, grounding, and compliance with shop drawings .
• Maintain records of inspection requests and approvals for QA/QC verification.

Labor and Productivity

• Typical installation requires 1 electrician, 2 highly skilled laborers, and 1 helper per group, with a productivity rate of approximately 0.08 hours per meter . By following these steps, ladder-type cable trays can be installed safely and efficiently in Gabon, ensuring compliance with international standards such as IEC 61537 and local building regulations .