How to install cable tray positioning elbows

Cable tray support elbows should be installed with proper spacing, secure mounting, and adherence to NEC and NEMA VE 2 standards to ensure safe and reliable cable routing.

Step 1: Plan the Route and Identify Elbow Locations

Before installation, mark the cable tray path on walls, ceilings, or supports using a chalk line or laser level. Identify where elbows (90° or 45° bends) are required for directional changes. Ensure the route avoids obstructions like HVAC ducts or pipes and allows sufficient clearance for cable installation and maintenance ( ).

Step 2: Determine Support Points

Elbows require additional support compared to straight sections. Position supports according to NEMA VE 2 guidelines:

• Place supports near the ends of the elbow and at intervals along the curve to prevent sagging.
• Avoid placing connectors at the center of spans; instead, locate them between the support point and the quarter-point of the span ( ).
• Standard support spacing for straight runs is typically 1.5 to 3 meters, but elbows may require closer spacing depending on load ( ).

Step 3: Select and Install Support Hardware

Use appropriate mounting brackets, wall arms, ceiling struts, or threaded rods rated for the tray load. Ensure the hardware can handle the maximum load per hanger, typically 318–340 kg (700–750 lbs) for center-hung supports ( ). Secure the supports firmly to the structural surface using anchor bolts or other approved fasteners.

Step 4: Install the Elbow Fitting

• Align the elbow with the adjoining straight tray sections.
• Use splice plates or connectors to join the elbow to the straight sections, allowing for longitudinal movement to accommodate thermal expansion ( ).
• Ensure the elbow is level and properly oriented to maintain smooth cable routing.

Step 5: Bonding and Grounding

• Install bonding jumpers at each elbow and expansion joint to maintain electrical continuity ( ).
• Ground the tray system at least every 15 meters (50 ft) and at both ends.
• For conduit drop-outs connected to the elbow, use a grounding bushing and bonding wire bolted to the tray.

Step 6: Final Checks

• Verify that the elbow and supports are secure, level, and free of sharp edges that could damage cables.
• Ensure the cable tray fill does not exceed the maximum fill ratio (usually 50%) and that cables can be pulled smoothly through the elbow without kinking ( ).
• Confirm compliance with NEC Article 392 and manufacturer specifications. By following these steps, cable tray elbows will be structurally supported, code-compliant, and safe for cable installation, ensuring long-term reliability and ease of maintenance.