Requirements for splicing communication optical cables at booster substations

Splicing optical cables at booster substations requires adherence to technical standards, proper cable preparation, and strict safety and grounding protocols to ensure performance and personnel safety.

Technical Requirements

Splice Quality and Stability: Splices must maintain low optical loss and high tensile strength, comparable to the fiber's proof-test level, and remain stable over the system's design life under expected environmental conditions. Both fusion and mechanical splicing are acceptable, with fusion splicing generally preferred for permanent, high-performance connections (ITU-T L.12) . Cable Types: Common optical cables in substations include OPGW (Optical Power Ground Wire), ADSS (All-Dielectric Self-Supporting), and SkyWrap. OPGW cables combine grounding and communication functions, often installed above high-voltage conductors, and require careful preparation for splicing due to their metallic and fiber components .

Cable Preparation

1. Marking and Stripping: Measure and mark 2–2.5 meters of cable to be stripped. Secure the cable with tape to prevent wire displacement during cutting .
2. Metal Layer Removal: Use a metal saw or mini grinder to carefully cut and remove outer and inner aluminum or steel strands. For OPGW with metal loose tubes, inner strands should extend ~10 mm beyond outer strands to expose the fiber tubes .
3. Fiber Tube Handling: If fibers are in plastic tubes, standard optical cable preparation applies. For metal tubes, install transportation tubes to protect fibers during splicing .

Safety and Grounding

Grounding Protocols: Before splicing, ensure proper grounding of the OPGW cable and any vehicles or equipment. Use ground rods, grip-all clamp sticks, and grounding cables to mitigate step and touch potential hazards . Personal Protective Equipment (PPE): Technicians must wear gloves, face shields, and other PPE to prevent injury from metal cutting and electrical hazards . Pre-Splicing Procedures: Conduct a Job Safety Analysis (JSA), inspect all tools and equipment, and consider weather conditions to ensure a safe working environment .

Splicing and Testing

• Fusion Splicing: Align fibers precisely and perform fusion splicing according to manufacturer and ITU-T L.12 standards to achieve minimal splice loss .
• Mechanical Splicing: Can be used for temporary or lower-performance connections but must still meet optical loss and stability requirements .
• Post-Splice Testing: Verify splice quality using optical time-domain reflectometers (OTDR) or power meters to ensure compliance with system performance specifications .

Summary

Splicing communication optical cables at booster substations involves technical precision, careful cable preparation, and rigorous safety measures. Following ITU-T L.12 standards, proper handling of OPGW or other optical cables, and grounding protocols ensures both system reliability and worker safety. Adhering to these requirements is essential for maintaining high-quality, long-lasting optical communication links in high-voltage environments.