How to splice a 72-core 3m fiber optic cable junction box

Splicing a 72-core fiber optic cable requires careful preparation, precise alignment, and organized management inside a junction box to ensure low loss and long-term reliability.Step 1: Prepare the CableStrip the Outer Jacket: Use a fiber cable stripper to remove the outer jacket and expose the buffer tubes. For a 72-core cable, carefully separate the individual fiber bundles to avoid tangling or damage .Remove Strength Members: Cut Kevlar or other strength members using a Kevlar cutter to prevent interference with splicing .Clean the Fibers: Wipe each fiber with lint-free wipes and isopropyl alcohol to remove dust, oils, or contaminants .Step 2: Cleave the FibersUse a high-precision fiber cleaver to create a smooth, perpendicular end face on each fiber. Proper cleaving is critical for low splice loss and optimal signal transmission .Step 3: Organize Fibers in the Junction BoxPlace the fibers into splice trays inside the junction box. For a 72-core cable, use multiple trays or layers to separate fibers into manageable groups (e.g., 12 or 24 fibers per tray) .Ensure fibers are routed with a minimum bend radius to prevent microbending or signal loss.Step 4: Splice the FibersMechanical Splicing: Align fibers in a mechanical splice connector with index-matching gel. This method is faster and does not require a fusion splicer, but typically has slightly higher insertion loss (~0.3 dB) .Fusion Splicing: Use a fusion splicer to weld fiber ends together. This provides the lowest loss (~0.1 dB) and is recommended for permanent, high-performance installations .Follow the splicer manufacturer's instructions for alignment, arc parameters, and securing fibers.Step 5: Protect the SplicesPlace each splice in a splice protection sleeve and secure it in the splice tray. This protects the fibers from environmental stress and mechanical damage .Ensure all excess fiber is coiled neatly in the tray to maintain organization and prevent strain.Step 6: Test and VerifyUse an OTDR (Optical Time Domain Reflectometer) or a power meter to verify each splice for signal integrity, insertion loss, and continuity .Document the results for each fiber core to ensure the 72-core cable meets performance standards.Step 7: Close the Junction BoxAfter testing, carefully close the junction box, ensuring all fibers remain organized and protected.Label each fiber or tray for future maintenance and troubleshooting. By following these steps, a 72-core fiber optic cable can be spliced efficiently and reliably inside a junction box, ensuring minimal signal loss and long-term network stability .