Partitions in cable trays are used to separate different types of cables and must comply with IEC 61537, NEC 392, and NEMA VE 1 standards to ensure safety, proper load distribution, and electromagnetic compatibility.

Key Standards and Guidelines

IEC 61537 specifies requirements for metal and nonmetallic cable trays, including the accommodation of partitions to separate power, control, and communication cables. Partitions must be designed to maintain mechanical strength, prevent cable sagging, and allow proper ventilation while supporting the intended cable load . NEC Article 392 emphasizes separation of high-power and low-power cables to prevent electromagnetic interference (EMI). Partitions or dividers are recommended when multiple cable types share the same tray, ensuring that fill limits are not exceeded (40% for power cables, 50% for control cables) and that vertical and horizontal clearances are maintained . NEMA VE 1 provides practical guidance for installing metal cable trays with partitions. It covers the use of solid or ventilated dividers, specifying that partitions should be securely fastened to the tray and made of materials compatible with the tray's construction (steel, aluminum, or fiberglass) to maintain grounding continuity and corrosion resistance .

Practical Considerations

• Material Selection: Partitions should match the tray material to avoid galvanic corrosion and maintain structural integrity. Aluminum, steel, or FRP are commonly used depending on environmental conditions .
• Spacing and Height: Partitions must allow adequate space for cable bending and maintenance access. Typical rung spacing is 150–230 mm, and partitions should not obstruct the minimum bend radius of cables .
• Grounding and Electrical Continuity: For metallic trays, partitions should not interrupt the tray's grounding path. IEC 61537 requires that trays used for bonding maintain a resistance of less than 0.1 ohms across joints .
• Installation: Partitions should be installed without damaging cables or the tray structure. They can be solid or ventilated depending on heat dissipation requirements and cable type .

Summary

Adding partitions to cable trays is governed by IEC 61537, NEC 392, and NEMA VE 1, which collectively ensure mechanical strength, electrical safety, proper cable separation, and EMI mitigation. Proper material selection, secure installation, and adherence to fill limits and clearances are essential for compliance and long-term reliability of cable management systems .