How to install cable tray elbows with partitions

Cable tray elbows should be installed with proper support, alignment, and bonding to ensure structural integrity and compliance with electrical standards.

Support and Positioning

Cable tray elbows must be supported according to NEMA VE 2 standards and manufacturer instructions. Supports should be positioned so that connectors between straight sections and elbows are not at the center of spans but between the support point and the quarter-point of the span to prevent sagging or stress on joints. Trapeze or swing supports are commonly used, with vertical hangers projecting through cross members to allow horizontal adjustment and proper leveling of the elbow.

Installation Steps

Prepare the Support System: Install vertical hangers and cross members, ensuring holes are slightly larger than the all-thread rods to allow adjustment. Attach the Elbow: Position the elbow section on the support system. Use tray clips (inside or outside the tray) to secure the elbow while allowing minor horizontal movement.

Level and Align: Adjust the cross members and nuts to ensure the elbow is level and aligned with adjoining straight sections. Connect to Straight Sections: Use manufacturer-supplied connectors to join the elbow to straight tray sections, ensuring a tight fit without over-stressing the tray. Bonding and Grounding: Install bonding jumpers at each elbow and expansion joint to maintain electrical continuity.

Ground the tray at intervals of 15 m (50 ft) and at both ends.

Cable Management Considerations

Maintain the minimum bend radius for cables exiting the elbow to prevent damage. Ensure cables are neatly laid within the tray, following spacing and layering guidelines to avoid overcrowding. For long runs or outdoor installations, provide expansion connectors at intervals of 30 m (100 ft) or as specified by NEMA VE 2.

Safety and Compliance

Follow the latest NEC and NEMA VE 2 standards for installation. Avoid placing connectors directly on supports or at the center of spans to prevent mechanical stress. Ensure all tray components are mechanically secure and capable of supporting the intended cable load, with maximum support spacing typically around 3.

6 m (12 ft) for standard trays. By adhering to these guidelines, cable tray elbow partitions can be installed safely, maintaining both structural integrity and electrical safety.