Voltage range

The voltage range has been assigned to the filter and it is expressed in terms of the upper and lower limits within which the filter is permitted to be placed in continuous operation. Whereas it is true that the lower limit is generally non-critical, the upper limit is determined by the insulation system and the dielectric strength, e.g. of the capacitors.

In a departure from the otherwise usual standard norm-oriented allocation of voltages for electrical equipment, here the upper limit will be marked by the rated voltage of the filter, unless labelled otherwise.