How to secure cable tray wiring

Secure cable trays by properly connecting sections, fastening with appropriate hardware, and ensuring grounding and support stability.

Step 1: Connect Cable Tray Sections

After wiring, ensure all tray sections are firmly joined. Common connection methods include splice plates, bolted connections, quick-connect systems, fish plates, and clamps. Splice plates are flat metal plates bolted to the ends of two tray sections, providing strong, reliable connections suitable for straight runs and heavy loads. Quick-connect systems allow faster installation but may be brand-specific and cost more upfront. Proper connections prevent sagging, maintain system stability, and facilitate future maintenance (ApexTray) .

Step 2: Fasten Trays to Supports

Cable trays must be secured to their supports using bolts, threaded rods, or suspension frames depending on the installation type. For ceiling installations, use threaded rods with expansion nuts; for wall-mounted trays, use bolts and brackets designed for horizontal or vertical support. Ensure all fasteners are tightened to withstand the weight of fully loaded trays and vibrations (ApexTray) .

Step 3: Use Cable Management Accessories

Install cable ties, clamps, or separators to maintain cable spacing and prevent movement within the tray. For instrumentation or control cables, consider trays with closer rung spacing or solid bottoms to prevent sagging and protect sensitive cables (ABB Technical Guide) .

Step 4: Grounding and Bonding

Cable trays often serve as an equipment grounding conductor (EGC). Use a specialized grounding wire with a multi-tooth or serrated washer to ensure electrical continuity at each connection point. This prevents static buildup, EMI, and reduces the risk of electric shock. Ensure all tray sections are electrically continuous and bonded according to NEC 392.60 requirements (ExpertCE, ApexTray) .

Step 5: Verify Stability and Compliance

After securing trays and wiring, check for level alignment, proper support spacing, and absence of sagging. Ladder trays typically require supports every 4–6 feet, while ventilated troughs may need closer spacing for smaller cables. Confirm that cable fill does not exceed NEC 392.22 limits to prevent overheating and maintain safety (ExpertCE, NEC Article 392) .

Step 6: Optional Covers

For additional protection, especially in high-traffic or dusty environments, install tray covers. Solid or ventilated covers protect cables from physical damage and reduce electromagnetic interference while maintaining airflow for heat dissipation (NEC Article 392) . By following these steps—connecting sections securely, fastening to supports, managing cables, grounding properly, and verifying compliance—you ensure a safe, durable, and code-compliant cable tray installation.