Segregate fiber optic cable from heavy copper cables to avoid bend radius violations and crush loads. Comply with National Electrical Code requirements for cable ratings and fire safety. This guide covers how to safeguard outdoor fiber optics across underground, aerial, direct-burial, and exposed setups. Use of Conduits and Ducts Conduits and ducts provide a physical. Outdoor fiber optic cables are installed in harsh environments where they are exposed to various environmental factors such as temperature changes, humidity, moisture, dust, and physical stress. Below are key best practices to follow during installation: 1.