The latest U.S. national standard for cable trays is NEMA BI 50016-2024, with NEC Article 392 providing installation requirements.

NEMA Standards

The National Electrical Manufacturers Association (NEMA) develops technical standards for cable trays. The most recent standard is NEMA BI 50016-2024, which provides updated guidelines for construction, materials, load capacity, dimensions, grounding, and connection methods for cable tray systems (including wire mesh, ladder, and solid-bottom types) . The previous standard, NEMA BI 50015, also covers wire mesh cable trays and UL-classified products, but BI 50016-2024 represents the latest revision .

UL and Safety Standards

For nonmetallic or fiberglass cable trays, UL 568 specifies performance and safety requirements, ensuring compliance with NEC rules and safe application in electrical installations . Products labeled as UL Classified have been independently tested against NEMA and NEC requirements.

NEC Requirements

The National Electrical Code (NEC) Article 392 governs cable tray systems in the U.S., covering installation, grounding, bonding, tray fill limits, and separation of power and data cables . Compliance with NEC ensures safety, reliability, and inspection approval.

International Considerations

For projects with international scope, IEC 61537:2023 provides requirements and tests for all-metal and nonmetallic cable trays, including corrosion classification and use as a protective earth conductor . While not a U.S. national standard, it is relevant for global projects.

Summary

• Latest U.S. standard: NEMA BI 50016-2024
• Installation and safety code: NEC Article 392
• Nonmetallic/fiberglass trays: UL 568
• International reference: IEC 61537:2023 These standards collectively ensure that cable tray systems are safe, reliable, and compliant with current electrical codes and industry best practices.