Proper cable tray installation in electrical wells requires careful planning, correct tray selection, secure support, and adherence to safety and code standards.Planning and Preparation
Before installation, review the approved shop drawings to determine tray layout, length, and routing within the electrical well . Inspect all materials to ensure they match the approved submittal and are free from damage. Store trays and ladders horizontally on a flat surface with timber supports at intervals of about one meter, protecting them from moisture and sunlight . Ensure all tools and equipment comply with contract and safety requirements.
Tray Selection
Choose the appropriate tray type based on cable type, load, and environment. Ladder trays are ideal for power cables due to ventilation and easy cable entry, while ventilated troughs support smaller control or instrumentation cables . Materials may include galvanized steel, aluminum, or fiberglass-reinforced plastic (FRP) for corrosion resistance and non-conductivity in wet or chemical-prone environments .
Support and Mounting
Install trays using center-hung supports or brackets, ensuring proper spacing to prevent sagging. Typical support spacing ranges from 1.5 to 3.6 meters, depending on tray type and load . Secure mounting is critical; use approved clamps, brackets, and connectors. Align trays straight and level, and handle materials carefully to avoid coating damage .
Installation Procedure
- Route Marking: Mark the tray path in the electrical well, considering clearance, cable separation, and future maintenance access .
- Tray Assembly: Connect tray sections using manufacturer-approved fittings, ensuring continuity and proper alignment .
- Cable Laying: Deposit cables into trays from each side if using center-hung supports, maintaining separation and avoiding overfilling .
- Bonding and Grounding: Ensure all trays are properly bonded and grounded according to NEC/IEC standards to prevent electrical hazards .
- Inspection: Verify alignment, support spacing, and secure connections before final handover .
Safety Considerations
Use scaffolding or working platforms as required within the electrical well. Follow lifting and handling protocols for trays, especially when using forklifts or cranes, to prevent crushing or damage . Conduct a pre-start meeting with the site engineer, H&S officer, and supervisor to review hazards and controls . Only qualified personnel should perform installation, following local electrical codes and manufacturer guidelines . By following these steps, cable tray systems in electrical wells can be installed safely, efficiently, and in compliance with code requirements, ensuring organized cable management and ease of future maintenance .
