How to pull the steel wire of optical fiber cable

Always pull fiber optic cables by the internal strength member (steel wire or Kevlar yarn), never by the outer jacket, to prevent damage to the glass fibers. Key Steps for Pulling Fiber Optic Cable1. Identify the Strength Member: Most fiber optic cables, especially armored or steel-reinforced types, have a central steel wire or Kevlar aramid yarn that serves as the strength member.

This is the part designed to handle tensile loads, not the outer jacket, which can stretch or tear if pulled directly. 2. Prepare the Cable for Pulling: Strip a small portion of the outer jacket to expose the strength member.

Loop the strength member through a cable pull-eye or wire mesh pulling grip. Secure the loop by doubling back and taping or knotting it to ensure it won't slip during the pull. 3.

Use Proper Pulling Tools: Pulling grips: Factory or field-installed wire mesh grips distribute tension evenly across the strength member and jacket. Breakaway swivels: These prevent twisting of the cable and protect it from exceeding maximum tension. The swivel will break if the pull exceeds the cable's rated tensile strength.

Lubricants: For long runs or tight conduits, use fiber-compatible lubricants to reduce friction and prevent jacket damage. 4. Observe Maximum Tension and Bend Radius: Check the cable specification sheet for the maximum pulling tension (e.g., stranded loose tube cables may allow up to 2,700 Newtons).

Respect the minimum bend radius: during pulling, it should be at least 20 times the cable diameter; after installation, at least 10 times the diameter. Avoid sharp 90° bends; use sweeping conduit bends or sweep elbows to reduce stress. 5.

Pulling Technique: Pull, do not push, the cable to avoid violating the bend radius. For long runs, consider pulling from the middle out to both ends or using an automated puller with tension control. Monitor the supply reel and communicate with the installation team to prevent cable snags or twisting.

6. Protect Cable Ends and Connectors: Cap bare cable ends to prevent moisture ingress. For pre-terminated cables, wrap connectors in tape and use a pulling mesh to protect them during the pull.

7.

Post-

Pull Testing: After installation, test the fiber with an OTDR (Optical Time-Domain Reflectometer) or Visual Fault Locator to ensure no micro-bends or breaks occurred during the pull. By following these steps, you ensure that the steel wire or strength member bears the pulling load, protecting the delicate optical fibers and maintaining the cable's performance and longevity.