Description Value Maximum tangent of loss angle(Tanδ) 0.001 at 1 kHz Voltage proof test between leads 4.3 times of the rated voltage value DC for 2 second Voltage proof test between leads and case 2 times of rated voltage+1500VAC with a minimum 2000 VAC for 2 second Insulation Resistance (RIS) CR≤0.33 µF CR>0.33 µF (or) time constant T= CR × RIS ≥15000 MΩ ≥5000 s at 25° C, relative humidity ≤70%