Fiber splice terminal box core retention order

Fibers in a splice terminal box should be arranged to maintain proper bend radius, minimize stress, and follow the manufacturer's tray sequence, typically from the cable entry to the splice point and then to the adapter ports.

Core Retention Principles

1. Fiber Routing and Bend Radius: Fibers should be carefully routed inside the splice tray to avoid sharp bends or pinching, which can cause breaks or signal loss. Maintain the minimum bend radius specified by the manufacturer, usually around 30–40 mm for single-mode fibers, and ensure fibers are not twisted excessively when stacking trays or closing covers . 2. Sequence from Cable to Splice:

• Begin by securing the incoming cable to the closure or terminal box.
• Extend the loose tube or buffered fibers from the cable entry to the splice tray.
• Organize fibers in the tray according to the core numbering or color code of the cable, ensuring each fiber is routed to its corresponding splice or pigtail .
• Typically, fibers are arranged sequentially from the lowest-numbered core to the highest, following the cable's color code standard (e.g., blue, orange, green, brown, etc.) to maintain consistency and simplify troubleshooting. 3. Splice Tray Management:
• Place fibers in the tray slots or holders without crossing or overlapping unnecessarily.
• For ribbon fibers, ensure ribbons are oriented correctly; hard ribbons bend only in one direction, while flex ribbons can bend in multiple directions .
• After splicing, store the excess fiber in the tray loops, maintaining the proper bend radius and avoiding stress points. 4. Adapter Port Connection:
• Route fibers from the splice point to the adapter ports in the order that matches the intended patching sequence.
• Ensure that the fiber length allows for future re-termination or relocation without exceeding bend limits . 5. Closure and Maintenance:
• Before closing the box, verify that no fibers are pinched by the tray cover.
• Use a visual fault locator (VFL) to check for breaks or high-loss points, as some breaks may be too close to the splice to detect with an OTDR .
• Document the core retention order for future maintenance and troubleshooting. By following these steps, the core retention order ensures organized fiber management, reduces the risk of damage, and maintains optimal optical performance in FTTH or other fiber optic networks.