Construction cable tray splicing

Cable tray splicing is achieved using splice plates that join sections securely while maintaining structural integrity and grounding continuity.

Types of Splice Plates

1. Flexible Horizontal Adjustable Splice Plates These allow horizontal direction changes when standard fittings do not fit. They are supplied in pairs with hardware and do not require bonding jumpers. Supports must be installed within 24 inches (600 mm) on both sides of the splice per NEMA VE2 standards. They are suitable for tray widths up to 36 inches, with side rail heights of 4–7 inches depending on the model (Eaton) .
2. KwikRail Splice Plates Designed for the KwikRail cable tray system, these plates use a two-bolt connection with standardized 1/4" hardware. The splice plate engages into the tray's side rail groove and is fully tightened to maintain structural integrity. Torque nuts to 8 ft-lbs to ensure proper engagement .

Installation Steps

1. Preparation
   • Determine the desired angle or alignment for the splice.
   • Field cut the cable tray or ladder to fit the installation, marking cut lines carefully and removing any affected rungs .
2. Positioning the Splice Plate
   • Align the splice plate with the side rails of the cable tray.
   • Engage the top of the splice plate into the retention groove and ensure full contact with the side rail .
3. Securing the Connection
   • Insert bolts through the splice holes and tighten to the recommended torque.
   • Verify that the splice maintains the tray's structural integrity and alignment .

Grounding and Bonding Considerations

• Metallic cable trays can serve as the Equipment Grounding Conductor (EGC) if installed by qualified personnel.
• Each splice should maintain electrical continuity; grounding clamps can be used to bond alternate tray sections to the EGC.
• For aluminum trays, avoid bare copper conductors to prevent electrolytic corrosion; use insulated conductors with insulation removed at bonding points .
• Ensure the tray side rails meet the minimum cross-sectional area requirements for grounding based on the system's fault current rating .

Best Practices

• Maintain proper support spacing near splices (typically within 24 inches).
• Use appropriate tools: wrenches, metal cutting tools, and drills; no specialized tools are required for most splice plates .
• Verify alignment and load capacity after splicing to prevent mechanical stress or cable damage.
• Consider material compatibility (aluminum vs. steel) to avoid corrosion and ensure long-term reliability . By following these guidelines, cable tray splicing can be performed safely, maintaining both mechanical strength and electrical continuity across the system.