Cable tray hangers should generally be spaced 1.5 to 3 meters apart, with closer spacing at bends, vertical runs, and heavy loads to ensure stability and prevent sagging.

Horizontal Runs

For straight horizontal cable tray sections, hangers are typically installed at intervals of 3 to 5 meters, depending on the tray type, cable weight, and material stiffness . Cables should also be secured at the start, end, and at every bend to prevent undue mechanical strain . When cables are clipped directly to a surface, spacing should follow guidance based on cable diameter and type, ensuring no damage from the cable's own weight .

Vertical Runs

Vertical cable tray runs require closer hanger spacing, generally less than 2 meters, with cables secured at the top and every 1.5 meters along the run . For long vertical runs exceeding 32 meters, strain relief sections should be incorporated, offsetting the cable by at least 2 cable diameters to prevent displacement due to thermal expansion .

Bends and Corners

At corners, T-junctions, or changes in direction, hangers should be installed on each side of the bend, arranged symmetrically to maintain tray stability and prevent cable stress . The internal radius of the bend should not be less than the cable's minimum bending radius, and supports should be applied on either side of the bend .

Flexible Systems

For flexible cable tray systems, such as J-hanger installations, the distance between supports must be calculated based on cable stiffness and allowable deflection (typically 2% sag). The Heinhold method can be used for major projects to determine support spacing according to cable design, size, and material .

General Recommendations

• Always use fire-resistant supports for all cable types to prevent premature failure .
• Fixed supports should be installed at tray start, end, and at intervals along long spans to distribute weight and prevent sagging .
• Ensure cables are laid straight and orderly, avoiding overlaps or protrusions, and all bends are securely fastened . By following these guidelines, cable tray systems will maintain mechanical integrity, comply with safety standards, and minimize stress on cables and terminations.