Maintenance of Cables
Visual inspection of the cable, conduit, manholes, and so on, and electrical maintenance testing are the major maintenance procedures for cable systems.
Visual inspection can be made on energized cables, but if cables are to be touched or moved they should be de-energized. Cables in vaults, substations rooms, manholes, and at other locations should be inspected for the following on a yearly basis:
1. Physical damage, sharp bends, and excessive tension
2. Oil leaks, soft spots, and insulation swelling
3. Poor ground connections, metallic-sheath bonding deterioration, corroded cable supports, and continuity of main grounding system
4. Cracked jackets of nonleaded cables
5. Damage to fireproofing
6. Tracking or corona
7. Soft spots in terminations and splices
8. Inspect the manhole for spalling concrete and standing water
9. Potheads should be inspected for oil or compound leaks (dirt and grime should be cleaned off and connections checked for tightness) Aerial cables should be inspected for mechanical damage caused by vibration or deterioration of support and suspension system. Inspection should be made of cables for insulation abrasion and cable being bent or pinched.