2021 Cable Tray Standard

Cable tray systems in 2021 are governed by standards such as NEMA VE 1, UL 568, IEC 61537, and CSA C22.2, covering metallic and nonmetallic trays, load ratings, installation, and safety compliance.

Key Standards

NEMA VE 1 specifies manufacturing requirements for metal cable trays including ladder, channel, wire mesh, and solid bottom types, along with associated fittings. It provides load/span class designations and aligns with the National Electrical Code (NEC) and Canadian Electrical Code (CEC), ensuring harmonized compliance for North American installations . UL 568 covers nonmetallic (fiberglass) cable trays, defining performance and safety requirements for continuous systems used to support power or control cables . IEC 61537 is the international standard for both metallic and nonmetallic cable trays, specifying requirements and tests for cable support, accommodation, and installation in electrical and communication systems . CSA C22.2 Specification #126.1 harmonizes with NEMA VE 1, providing Canadian compliance for metallic cable tray systems .

Installation and Design Considerations

Cable trays can be ladder, ventilated, solid bottom, or channel types, and must be selected based on cable type, load, and environmental conditions . Key design factors include:

• Rung spacing: Typically 6–9 inches (150–230 mm) for proper cable support and bend radius .
• Support spacing: Distance between brackets or suspension points must accommodate load and prevent sagging .
• Material selection: Aluminum, steel, or stainless steel are chosen based on corrosion resistance, mechanical strength, and environmental exposure .
• Fittings and accessories: Include bends, T-pieces, crossovers, and covers to ensure safe routing and protection of cables .

Compliance and Certification

Cable trays must comply with national and international directives, including CE marking in Europe and UL certification in the USA. Compliance is verified through third-party audits and testing for mechanical, electrical, and environmental performance . Environmental considerations are increasingly important, with life cycle analysis and RoHS compliance guiding material selection and manufacturing processes .

Practical Guidance

Manufacturers provide technical guides and catalogs to assist engineers and contractors in selecting the correct tray type, material, and fittings for specific applications. Tools like Eaton's submittal builder allow for CAD/BIM integration and detailed specification downloads . In summary, the 2021 cable tray standards ensure safe, reliable, and code-compliant installation of both metallic and nonmetallic cable trays, addressing mechanical strength, electrical safety, environmental factors, and proper support design.