How is oil leakage in a transformer detected during maintenance inspections?

Transformer oil leakage is detected through routine visual inspections, oil level monitoring, and condition indicators. Technicians look for wet spots on tanks, radiators, gaskets, bushings, and valves, as well as oil stains on foundations or containment pits. Oil level gauges and conservator indicators help identify gradual losses. Infrared thermography may reveal cooling inefficiencies caused by low oil levels. Sudden pressure relay alarms or Buchholz relay activation can also signal internal oil loss. Early detection is critical to prevent insulation exposure and moisture ingress.