Essential maintenance practices include:

Regular Oil Testing: Monitoring dielectric strength, moisture content, and contamination levels.
Oil Purification: Removing impurities through filtration, degassing, and dehydration.
Leak Detection and Repair: Ensuring the cable system is sealed to prevent oil loss and contamination ingress.
Temperature Monitoring: Keeping operating temperatures within specified limits to prevent oil degradation.
Oil Level Checks: Maintaining proper oil levels to ensure adequate insulation and cooling.
These practices help maintain the oil’s insulating properties and extend the cable’s service life.