How to use the 3M2178 fiber optic splice closure

The 3M 2178 fiber optic splice closure is installed by preparing the cables, placing fibers in splice trays, bonding shielded cables if needed, and sealing the closure with proper gaskets and fasteners.

Step 1: Cable Preparation

• Remove the outer cable sheath carefully to avoid cutting or damaging the fibers underneath. Typically, remove 96 inches (2.43 m) of outer sheath for main cables and 48 inches (1.2 m) for branch or drop cables, adjusting for LXE cables as needed .
• Strip successive layers to expose the primary buffer tubes protecting the fibers. Clean all buffer tubes and dielectric strands to remove grease or debris .
• For armored or shielded cables, prepare the cable for a 4460-D Shield Bond Connector installation, ensuring the underlying layers are not damaged .

Step 2: Splice Tray Installation

• Use the 3M splice trays to organize and protect the fibers. The 2178 closure can accommodate multiple trays depending on fiber count and tray size .
• Place fibers in the trays, securing them with fusion splice holders or other compatible holders. Positionable or fixed splice inserts allow flexibility for different splice types .
• Ensure fibers are neatly routed to avoid bending below the minimum bend radius.

Step 3: Cable Bonding and Retention

• For shielded cables, install the shield bond connector and secure the cable with retention clamps.
• Build tape collars around the cable to the required diameter (e.g., 1.45" for large ports, 1.05" for smaller ports) using the provided tape collar gauge .
• Apply a thin coat of silicone lubricant to all surfaces of the cable ports and tape collars before inserting them into the closure gaskets .

Step 4: Closure Assembly

• Place the prepared cables and splice trays into the closure body.
• Align the gasket and dome, then secure the bolted halves to ensure a tight seal. The reusable gasket allows for easy re-entry if maintenance or expansion is needed .
• For drop cables, determine the number of drops passing through the multiport grommet, strip the sheath as required, and insert into the appropriate ports .

Step 5: Final Checks

• Verify that all fibers are properly secured, no sharp bends exist, and all ports are sealed.
• Tighten hose clamps or bolts to the specified torque (e.g., 40 in-lbs ± 5 in-lbs) for armored cables .
• Confirm that the closure is fully sealed and ready for environmental protection.

Tips for Re-entry and Expansion

• The 2178 closure is designed for easy re-entry. Simply remove the dome, access the splice trays, and add or replace fibers as needed.
• Use 3M Cable Addition Kits (2181 series) for adding new cables or ports without compromising the existing splices . By following these steps, the 3M 2178 fiber optic splice closure can be installed, maintained, and expanded efficiently while ensuring fiber protection and environmental sealing.