What routine inspections are performed on an oil filled transformer at substations?

Routine inspections include checking oil level indicators, leaks at gaskets and bushings, radiator condition, cooling fan and pump operation, and temperature gauges. Breathers and silica gel are inspected for moisture saturation. Bushings are checked for cracking, contamination, and abnormal heating. Oil samples are taken periodically for moisture, acidity, dielectric strength, and DGA. Protective devices such as pressure relief and alarms are tested as scheduled. Visual checks for unusual noise, odor, or discoloration support early fault detection.