Cable tray and elbow connection

Cable tray elbows should be connected using proper fittings, supported according to NEMA VE 2 standards, and aligned to maintain cable integrity and electrical continuity.

Connection Procedure

1. Select the Appropriate Elbow Fitting Cable tray elbows are available in horizontal, vertical, and adjustable angles. Choose the elbow type that matches the required change in direction while maintaining the minimum bend radius for the cables inside the tray .
2. Align and Join Sections
   • Position the elbow between the straight tray sections.
   • Ensure the ends of the trays are flush and properly aligned to prevent gaps or misalignment that could damage cables.
   • Use tray connectors or splice plates provided by the manufacturer to secure the elbow to the straight sections .
3. Secure with Fasteners
   • Bolt the elbow to the straight tray sections using appropriate hardware (nuts, bolts, and washers).
   • Some installations allow inside or outside tray clip placement, depending on space and interference with rungs .
   • Ensure fasteners allow for longitudinal movement if expansion or contraction is expected.

Support Requirements

• Support Spacing: Place supports near the elbow, typically between the elbow and the quarter-point of the span of the straight tray sections. Avoid placing connectors at the center of spans or directly on supports .
• Trapeze or Swing Supports: Common methods include trapeze hangers or swing supports, which allow for vertical and horizontal adjustment to maintain level alignment .
• Expansion Considerations: For long runs or outdoor trays, provide expansion connectors at intervals (e.g., every 30 m) and at building expansion joints, with bonding jumpers to maintain electrical continuity .

Bonding and Grounding

• Install a bonding jumper at each elbow if it coincides with an expansion joint or as required by the system design.
• Ground the tray system at least every 15 m and at both ends to ensure electrical safety .
• Conduit drop-outs connected to the tray should also be bonded using a compression lug or grounding bushing.

Best Practices

• Maintain the minimum bend radius for cables to prevent damage.
• Ensure neat cable routing inside the elbow to avoid overcrowding.
• Verify that all connections are tight, level, and aligned before laying cables.
• Follow manufacturer instructions and applicable codes (NEC, NEMA VE 2) for installation compliance . By following these steps, cable tray elbows can be installed safely, maintain structural integrity, and ensure reliable electrical performance.