Description

This package addresses supply cables laid directly in soil or through underground conduits that suffer from insulation resistance decline due to prolonged moisture ingress, chemical seepage, or ground settlement tension. We begin by isolating both ends of the cable, applying a rated DC test voltage with a high-voltage insulation tester, and reading the 60-second and 600-second insulation resistance values to determine the absorption ratio trend—indicating the degree of moisture absorption or aging. For circuits with notably low values, we use a cable path locator combined with a fault distance meter to project the approximate location of insulation weakness on the ground surface.

After narrowing down the suspected fault interval, we coordinate localized excavation or visual inspection through existing manholes, photographing and measuring sheath damage, cracks, or water ingress at intermediate joints. Based on findings, we perform localized sheath repair using cross-linked heat-shrink tubing in multiple overlapping layers, or for severely waterlogged joints, we cut and remake the joint entirely. All repairs are backfilled with anaerobic sealing compound and wrapped with waterproof self-amalgamating tape to ensure the repaired point’s protection level meets or exceeds the original cable design.

This locating and repair plan is fully customized based on the actual buried path length, soil survey data, and original laying drawings you provide. A deposit is required, covering the on-site setup of locating instruments and ground projection operations, with the amount estimated based on the total cable length and suspected fault points. After repairs are completed and insulation re-test passes, the final balance is settled according to the actual number of excavation or manhole interventions, the number of joints repaired, and the quantity of heat-shrink materials used.