Cable tray installation with hanger

Proper cable tray installation with hangers ensures safe, stable, and code-compliant support for electrical cables.

Planning and Preparation

Before installation, plan the tray route considering clearance, load capacity, and cable separation from other services like HVAC or plumbing. Mark the path using a chalk line or laser level and identify points for bends, tees, or elevation changes. Ensure the area is clear of obstructions and that all necessary tools and PPE (gloves, safety glasses, hard hat) are available.

Selecting Hangers and Supports

Cable trays are supported using threaded rods, trapeze hangers, or Unistrut channels. Beam clamps are preferred over drilling into steel beams to avoid structural damage. Use lock nuts to prevent loosening due to vibration in industrial environments.

Support spacing typically ranges from 1. 5 to 3 meters, depending on tray type and cable weight. Heavier loads require closer spacing, around 1.

5 meters.

Installation Steps

Attach Hangers: Install threaded rods or trapeze hangers at marked support points. Secure with nuts and washers, ensuring the support is level. Mount Strut or Channel: Connect a horizontal Unistrut or trapeze channel between hangers to create a shelf for the tray.

Place Tray Sections: Lift tray sections onto the supports. Align them straight and level. Join Sections: Use splice plates or couplers to connect tray ends.

Insert mushroom-head bolts from inside to prevent cable snagging and tighten nuts on the outside. Secure and Ground: Fasten trays to supports with hold-down clips or bolts. Install copper bonding jumpers across splices if the splice plate is not rated for grounding continuity.

Connect the system to the building's main earth ground.

Material and Load Considerations

Materials: Steel (galvanized or stainless), aluminum, or fiberglass depending on environment. Load Capacity: Maximum load per hanger is typically 318–340 kg (700–750 lbs) with a maximum support spacing of 3. 6 meters.

Corrosion Protection: Use hot-dip galvanized finishes in wet areas to prevent rust.

Safety and Compliance

Follow NE

C or local electrical codes for tray fill ratios (usually max 50%) and support spacing. Ensure trays are not used as walkways or ladders to prevent injury and system damage. Deburr all cut edges to prevent cable insulation damage.

Store trays properly before installation to avoid deformation or corrosion. By following these steps and guidelines, cable tray systems will remain stable, safe, and maintainable, supporting cables effectively while minimizing long-term maintenance issues.