Type Test: (As per IEC 60137) Dry Power-frequency Voltage withstand test Wet Power frequency Voltage withstand test Dry lightning impulse Voltage withstand test Temperature rise test Cantilever load withstand test Verification of dimensions Routine Test (As per IEC 60137) Tightness /Pressure test at 60°C Oil Dry power frequency voltage withstand test Visual inspection & dimensional checks Insulation Resistance