How to pierce cable trays

Piercing cable trays involves carefully drilling or cutting holes to allow cable routing or mounting, while maintaining tray integrity and safety.

Tools and Safety Equipment

Before piercing a cable tray, ensure you have the proper tools and personal protective equipment (PPE):

• Tools: Power drill with metal bits, hole saws, step drill bits, angle grinder (for larger openings), deburring tool or file, measuring tape, and marker for layout .
• PPE: Safety glasses, gloves, and a hard hat to protect against metal shards and debris .

Steps to Pierce a Cable Tray

1. Plan the Location: Determine where the hole is needed for cable entry, conduit, or mounting hardware. Avoid cutting near tray joints or structural supports to maintain strength .
2. Mark the Spot: Use a marker or center punch to indicate the exact location. A center punch helps prevent the drill bit from slipping on metal surfaces .
3. Drill the Hole:
   • For small holes, use a standard metal drill bit.
   • For larger openings, a step drill bit or hole saw is recommended.
   • Drill slowly to avoid overheating and maintain control .
4. Deburr the Edges: After drilling, use a file or deburring tool to remove sharp edges. This prevents cable insulation from being damaged and reduces the risk of injury .
5. Check Structural Integrity: Ensure the tray remains strong and stable. Avoid piercing too close to bends or joints, which could weaken the tray .
6. Install Cables or Accessories: Once the hole is clean and smooth, route cables or attach mounting hardware as needed. Use grommets or bushings to protect cables from sharp edges .

Additional Tips

• Avoid Overloading: Ensure the tray can still support the weight of cables after piercing. Follow manufacturer specifications for load and support spacing .
• Use Proper Fasteners: If attaching accessories, use bolts, clamps, or splice plates compatible with the tray type .
• Follow Codes: Adhere to NEC or local electrical codes regarding tray modifications and cable routing . By following these steps, you can safely pierce cable trays for cable routing or mounting without compromising the tray's structural integrity or electrical safety.