The main causes of moisture in XLPE insulated power cables are:
(1) Water ingress due to unsealed structure or poor installation of the joint box or terminal box.
(2) Cable manufacturing defects, small holes or cracks in the metal sheath.
(3) During cable transportation, construction, or operation, damage to the cable sheath due to external forces.
(4) During cable test or operation, the cable insulation breaks down and destroys the cable sheath.
(5) The operating environment is corrosive, and the cable sheath is corroded and damaged.
Anti-moisture measures for XLPE insulated power cables include:
(1) When purchasing cables, manufacturers with good quality must be selected, and strict tests shall be carried out on the samples submitted by each cable manufacturer.
(2) Ensure that the cable ends are well sealed. For sawn cable ends, whether stacked or laid, special sealing sleeves shall be used to prevent moisture infiltration.
(3) After the wire is laid, the cable head shall be made in time. If it is impossible to make it immediately due to conditions, the cable head shall be sealed and placed overhead.
(4) Improve the manufacturing process of strong cable head to prevent water from entering the cable head during the manufacturing process.
(5) During cable laying, construction measures shall be taken to prevent the cable sheath from being damaged by external forces.
(6) If the operating environment is corrosive or termite, the cable and laying mode shall be reasonably selected.