In the majority of cases, covers are not used on cable trays for technical or safety reasons, but due to the “raceway complex,” a feeling by specifiers that cables must be totally enclosed in metal. Quality tray cables have a life of 30 to 40 years without covers when. Cable trays, commonly used in electrical installations, help organize and protect wiring systems. However, these trays are not immune to safety hazards that could cause system failures, fires, or other catastrophic events. For. The use and installation of cable trays is covered by legally enforceable OSHA regulations in 29 CFR 1910.