Capacitors designed for DC voltages produce no internal heating. Therefore they often can be used with more or less reduced voltages up to the so called upper category voltage where the temperature characteristics of the material put a limit. This occur at the upper category temperature, TUC, in other nomenclatures called maximum usage temperature. The connections are shown in the following Figure C3-27. Varying derating curves are shown in MIL-HDBK-1547.
Figure C3-27. Typical voltage derating at the upper category temperature.