Appliances shall be constructed so that creepage distances are not less than those appropriate for the working voltage, taking into account the material group and the pollution degree.NOTE 1 The working voltage for parts connected to the neutral is the same as for parts connected to the phase and this is the working voltage for basic insulation.Pollution degree 2 applies unless– precautions have been taken to protect the insulation, in which case pollution degree 1 applies;– the insulation is subjected to conductive pollution, in which case pollution degree 3 applies.NOTE 2 An explanation of pollution degree is given in Annex M.Compliance is checked by measurement.NOTE 3 The way in which creepage distances are measured is specified in IEC 60664-1.Parts such as hexagonal nuts that can be tightened to different positions during assembly, and movable parts are placed in the most unfavourable position.A force is applied to bare conductors, other than those of heating elements, and accessible surfaces to try to reduce creepage distances when making the measurement. The force is– 2 N, for bare conductors;– 30 N, for accessible surfaces.The force is applied by means of test probe B of IEC 61032.