Cable tray hangers should be installed with minimal deviation from design alignment, maintaining proper spacing and level to ensure structural integrity and cable safety.

Installation Tolerances and Deviations

Cable tray hangers are critical for supporting cable trays and ensuring that cables remain secure and undamaged. Deviation in hanger installation refers to misalignment, uneven spacing, or sagging that exceeds recommended tolerances. Excessive deviation can lead to cable stress, improper load distribution, and potential safety hazards .

Recommended Practices

1. Hanger Spacing:
   • For standard cable trays, hangers are typically spaced according to the tray type and load. For example, solid-bottom or ventilated trays often require hangers every 1.5 to 3 meters (5–10 feet) for medium loads .
   • Mesh or ladder trays may require closer spacing, especially for heavy or instrumentation cables.
2. Alignment and Leveling:
   • Hangers should maintain the tray in a level plane to prevent sagging. Minor deviations are acceptable but should not exceed the manufacturer's specified tolerance, often around ±10 mm per meter of tray length .
   • Vertical deviations should be minimized to avoid stress on cable terminations and connectors.
3. Corrective Measures:
   • If a hanger is misaligned, it should be adjusted or replaced to restore proper tray alignment.
   • Use shims or adjustable supports where minor deviations occur to maintain level and spacing.
4. Load Considerations:
   • Ensure that the installed hangers can support the maximum expected cable load plus a safety factor. Overloading can exacerbate deviations and cause permanent sag .
5. Environmental Factors:
   • Consider thermal expansion, vibration, and corrosion. Stainless steel or galvanized hangers may be required in corrosive environments to maintain long-term alignment .

Compliance and Safety

• Installation should comply with BS EN 61537 or equivalent standards, which define the mechanical and electrical requirements for cable tray systems .
• Only competent personnel familiar with electrical installation practices should perform hanger installation to ensure safety and adherence to design specifications .

Summary

Proper cable tray hanger installation requires accurate spacing, level alignment, and adherence to load specifications. Deviations should be minimized and corrected promptly to prevent cable damage, maintain system integrity, and comply with safety standards. Regular inspection and maintenance are recommended to ensure long-term performance and safety of the cable support system .