Documents/Reports

• Maintenance
  
  • Patrolling
    Patrolling is being conducted to prevent the OPGW equipment from secondary damage and also to maintain a smooth operation of the equipment by detecting an abnormality in the equipment in its early stage, which is general survey based on the visual inspection of external appearance.
    Contents of practice, a method and cycle are correspondingly being executed to the existing overhead ground wire as a basic line, and some new items have been supplemented along with the addition of the function as a fiber optic transmission line.

Table-1 shows the added details being conducted currently as a standard procedure.

Table-1 : Details of the patrol as to OPGW and its belongings

• Inspection
  Inspection is being conducted to detect a lowering of function due to a long term use, etc. in overhead ground wires and fiber optic transmission lines, and to prevent the possible occurrence of an abnormality in the equipment, which is a quality inspection by means of a visual check with inspection tools, etc. Details of Inspection and method and cycle are as follows.
  • Inspection of OPGW and belongings
    The inspection is being conducted correspondingly to the existing over head ground wire as a basic line, and some new items have been added.
    
    

    Table-2 shows added details of the inspection being practiced currently as a standard.

    Sr. No.	Place to be Inspected	Cycle	Method	Note
    1.	Clamp region Jumper region	Same as existing ground wires (Approx. 1year 1 time)	Visual inspection of external appearance with the naked eye or binocular	If the rust gathered on bolts, etc. If there is any unusual abrasion on the moving part of hanging clamp. How is the status of OPGW in regard with corrosion If OPGW secures the allowable bending radius
    			Measurement of tightening torque with a torque wrench	All clamps bolts
    2.	Wiring region	Same as above	Same as above	If the fixed space by cleat is appropriate If OPGW is in contact with tower
    			Measurement of tightening torque with a torque wrench	All Cleats bolts
    3.	Inserting region of fiber optic joint box	Same as above	Same as above	If OPGW is slipping at clamp portion
    4.	Span region	Same as existing ground wires (Approx. 1year 1 time)	Visual inspection of external appearance with the naked eye or binocular	If there are arc marks on the OPGW How is the state of corrosion on the OPGW If all dampers and twist prevention weights are in place normally How is the state of corrosion on those
    5.	Inside the fiber optic joint box (when an abnormality occurred in fiber optic transmission system, the door is opened very rarely)	Every time when the door opened	Visual inspection of external appearance with the naked eye or binocular	If moisture penetration or dew condensation is observable If rust or corrosion is observable Any abnormality in the arrangement of housing tray and optical fiber installation into it If those is any bolt coming loose or missing

    Table-2 : Details of the inspection of OPGW and its belongings

  • Inspection of fiber optic transmission system

    The inspection of fiber optic transmission lines is being conducted for the same purpose as above OPGW and belongings to seize the state of deterioration of transmission lines.

    Table-3 shows details of the inspection being conducted as a standard procedure.

    Sr. No.	Place to be Inspected	Cycle	Method	Note
    1.	Fiber optic transmission line (check the unused cores out of the fiber enclosed)	Once in a three years period for instant	Measurement of transmission loss between light receiving level and terminal station with a power meter Measurement of a loss in connection with a part due to OTDR, and local loss increase in the line	How is the situation of light receiving level against the planned values How is the situation of transmission loss against the planned values. Also if there is a change due to again

    Table-3 : Details of inspection on the fiber optic transmission system