proof voltage

For cables, passive and active components, the characteristic value of dielectric strength indicates the voltage at which the corresponding component can still be operated.

For capacitors, the dielectric strength is the voltage value that lies below the dielectric strength. It depends on the dielectric, is specified for DC and AC voltage and is valid up to a certain temperature; usually below 40°C. For ease of comparison, dielectric strength values are based on the one micrometer (µm) thickness of the dielectric. For most dielectrics, dielectric strength ranges from 450 V/µm for polyphenylene sulfide( PPS), 455 V/µm for niobium pentoxide, and 750 V/µm for aluminum oxide( Al2O3). Ceramic capacitors, with their ferroelectric dielectrics, have much lower values than 100 V/µm.

For cables, the dielectric strength depends on the insulating material. For the common insulating materials polyvinyl chloride( PVC), polyethylene( PE), polyamide( PA) and polypropylene( PP), the dielectric strength values are between 40 kV/mm (PE and PVC), 55 kV/mm (PA) and 75 kV/mm (PP).