NEMA BI 50051 standard for Cat Van Loi wire mesh cable tray is the standard for Metal Cable Tray Systems. The latest edition (2024) defines strict requirements for: Construction, materials, and load capacity. The Cable Tray ng standards, performance standards, test standards and application in this document have been tested extens ompetent professional en completely installed, without damage either to conductors or. OBO BETTERMANN has offered prod-ucts and solutions for electrical instal-lation for over 100 years. With our many years of experience, we are one of the leading manufacturers in this field. Excellent electrical continuity and grounding is essential for s fe installations and reduces shock hazards. Founded in 1926 and headquartered in Virginia, NEMA develops hundreds of technical standards that improve safety, efficiency, and.