Power capacitor has been used to compensate for the low power factor of inductive load and to reduce harmonics generated by the power conversion device with reactor. The increase of voltage and current and thermal generation are extremely hard on the life of condenser. Current will be increased, provided that voltage and frequency of condenser increase also. The increase of voltage and frequency justly extends thermal generation. Both act on insulation stress and can afford to premature fault In this paper, we measured thermal distribution of condenser with infrared rays camera in case of variance of voltage and frequency. We were assured that the increase of voltage and frequency produces high heat and exceedingly shortens the life of condenser.