When vertically installed, the height of cable trays from the ground should not be lower than 1. If the above standards cannot be met, metal covers must be added for protection. These DWG files provide a full range of electrical system installation details, including cable tray supports, power outlets, isolator switch configurations, fuel tank arrangements, fire alarm installation, exit lighting layouts, and more. This does not apply. OBO BETTERMANN has offered prod-ucts and solutions for electrical instal-lation for over 100 years.