How to coil overhead optical cables

Overhead optical cables should be coiled in a controlled “U” shape, respecting the minimum bend radius, and secured to poles or suspension wires to prevent damage and maintain performance.

Key Steps for Coiling Overhead Optical Cables

1. Determine Coil Location and Length Reserve cable length for coiling at specific points along the route. Typically, a coil is placed every 10 poles, with a reserved length of 10 meters per coil. At cable ends and near junction boxes, reserve 8–20 meters to allow for future splicing or maintenance . 2. Form the Coil Properly

• Use a “U”-shaped expansion bend for each coil.
• Maintain the cable print consistently on the inside or outside of the U-shape throughout the coil to prevent twisting .
• Ensure the coil diameter is sufficient, commonly around 60 cm, to avoid exceeding the cable's minimum bend radius . 3. Respect Minimum Bend Radius
• The minimum bend radius is typically 10 times the cable's outer diameter for operating conditions.
• Avoid sharp bends or kinks, as these can cause microbending losses and signal degradation . 4. Secure the Coil
• Attach the coil to a messenger wire, pole, or other solid structure.
• Ensure the coil is stable and does not move in wind or vibration.
• Keep the lowest point of the coil 25–30 cm away from the suspension wire to prevent contact and abrasion . 5. Protect the Cable
• Use corrugated tubes or protective sleeves where the cable contacts poles or crosses other utilities.
• For special sections like bridges or rivers, adjust coil placement and protection according to environmental conditions . 6. Follow Installation Standards
• Check the cable specification sheet for tensile strength, temperature range, and bend radius.
• Use proper handling techniques to avoid exceeding pulling force limits during installation .

Practical Tips

• Always coil the cable in the same orientation to prevent twisting.
• Avoid stacking coils too tightly; allow airflow to reduce heat buildup.
• Label coils clearly for future maintenance. By following these steps, overhead optical cables can be coiled safely, ensuring long-term reliability, minimal signal loss, and ease of future maintenance .