OPPC junction boxes are installed at intermediate points between towers and at terminal points of the line, with placement depending on tower type and line design.

Types and Placement

Intermediate Joint Boxes: These are positioned along the transmission line between towers to connect sections of OPPC cable. The installation location is chosen to:

• Maintain the minimum bending radius of the OPPC cable (≥ 37.5 mm)
• Avoid interference from wind-induced pendulum motion
• Ensure safe equipotential connection for both power and communication signals Intermediate boxes can be pillar-mounted or hanging-mounted, depending on the tower structure and line design . Terminal Joint Boxes: These are located at the end points of the OPPC line, typically at substations or transition points. Terminal boxes often include both a lower and upper section to facilitate cable entry and exit, and they serve as the cut-off point for operational management and maintenance .

Installation Considerations

• The joint box must be fixed securely to a bench or tower structure to prevent movement.
• The bending radius of the fiber inside the OPPC must be preserved to avoid signal loss.
• Boxes are designed to withstand temperature variations (-40 to 70°C) and mechanical stress from line tension and environmental factors .
• Proper grounding and equipotential connections are required to safely isolate high voltage from communication signals .

Operational Notes

• OPPC junction boxes are part of the line's communication and power system, so they must be included in daily operation and maintenance routines.
• The photoelectric separation occurs at terminal boxes, marking the operational boundary for maintenance teams .
• After installation, bidirectional fiber testing is recommended to ensure minimal signal loss and proper connectivity . In summary, OPPC junction boxes are strategically located at intermediate points along the line and at terminal ends, with their exact placement determined by tower type, line tension, and operational safety requirements. Proper installation ensures both mechanical protection and reliable signal transmission.