Cable tray jumpers are installed to ensure electrical continuity and grounding across tray sections, particularly at expansion joints or painted trays.

Step 1: Identify Where Jumpers Are Needed

Cable tray jumpers are required when:

• The tray has expansion joints or adjustable fittings
• The tray is painted or powder-coated, which can block electrical continuity
• The installation is in a high-vibration environment
• UL-rated splice plates are insufficient to maintain grounding continuity Always check that the connection resistance is below 0.0003 ohms to ensure safety and compliance ( ).

Step 2: Gather Materials and Tools

• Bonding jumper cable: Typically 2 AWG soft drawn tin-plated copper stranded cable with flame-retardant PVC insulation ( )
• Bolts and lugs: Usually 5/16” square holes on the tray channel
• Tools: Wrenches, screwdrivers, and possibly a torque wrench for secure connections

Step 3: Prepare the Cable Tray

• Ensure the tray sections are properly aligned and supported
• Remove any paint or debris at the connection points if necessary to ensure good metal-to-metal contact
• Identify the channel ends where the jumper will be bolted ( )

Step 4: Install the Jumper

1. Position the bonding jumper across the discontinuity (e.g., expansion joint or splice plate)
2. Bolt each lug of the jumper directly to the tray channel using the designated 5/16” square holes
3. Do not attach the jumper to the splice plate bolts or pins; only connect to the tray channel ( )
4. Ensure the jumper is secure and free of tension, allowing for tray movement if applicable

Step 5: Verify Electrical Continuity

• After installation, measure the resistance across the jumper to confirm it is below 0.0003 ohms
• Check that all bolts are tight and that the jumper is not in contact with sharp edges that could damage insulation

Step 6: Final Inspection

• Confirm that the jumper does not interfere with cable placement or maintenance access
• Ensure compliance with NEC or local electrical codes regarding grounding and bonding By following these steps, cable tray jumpers will provide reliable grounding, maintain electrical continuity, and help pass site inspections without compromising safety ( ).