Horizontal leveling of cable tray supports is achieved by using adjustable hangers, threaded rods, clamps, and flexible splice plates to ensure the tray is uniformly supported and aligned.

Step-by-Step Horizontal Adjustment

1. Prepare the Supports and Tools

• Use threaded rods, clamps, and washers as primary support elements. Pre-thread nuts on the rods to facilitate adjustment .
• Tools needed include a wrench, drill, and optionally a metal cutting tool if field modifications are required .

2. Establish the Desired Elevation

• Hang a few supports along the tray run and use a carpenter's string or baling wire from end to end to mark the horizontal level .
• This string acts as a reference line to ensure all supports are aligned at the same height.

3. Position the Cable Tray

• Place the tray section onto the supports, ensuring the threaded rods pass through the clamp holes. Use round washers between the nuts and the clamp to distribute load evenly .
• Adjust the tray vertically by turning the nuts until the bottom of the tray reaches the desired horizontal level. The upper nuts are then tightened to secure the clamps in place .

4. Use Flexible Horizontal Adjustable Splice Plates (if needed)

• For horizontal direction changes or minor alignment corrections, install flexible horizontal adjustable splice plates between tray sections .
• Determine the desired angle, field cut the tray if necessary, and attach the splice plates with the provided hardware. Ensure supports are within 24 inches (600 mm) on both sides of the splice .

5. Check Support Spacing and Load

• Ensure supports are spaced according to manufacturer recommendations and NEC guidelines, typically 4–6 feet for horizontal runs .
• Verify that the tray is level across all supports and that the load is evenly distributed to prevent stress or sagging .

6. Final Securing

• Once the tray is level and aligned, tighten all nuts and clamps securely. Double-check the horizontal alignment along the entire run using a level or string line .

Best Practices

• Shorter vertical rods allow less horizontal adjustment, so plan rod lengths carefully .
• Precut rods and pre-thread nuts at the factory when possible to save time and ensure accuracy .
• Always follow manufacturer specifications for tray type, support spacing, and load capacity .
• Use bonding jumpers only if required; many flexible splice plates do not require them .

By following these steps, cable trays can be horizontally leveled and securely supported, ensuring safe and reliable cable management.