Accessible metal parts of class I tools, which may become live in the event of an insulation fault, shall be permanently and reliably connected to an earthing terminal or termination within the tool, or to the earthing contact of the tool inlet.The printed conductors of printed circuit boards shall not be used to provide continuity of the protective earthing circuit.Earthing terminals and earthing contacts shall not be electrically connected to the neutral terminal.Class II and class III tools shall have no provision for earthing.If accessible metal parts are screened from live parts by metal parts which are connected to the earthing terminal or termination, or to the earthing contact, they are not, for the purpose of this requirement, regarded as likely to become live in the event of an insulation fault.Accessible metal parts, which are separated from live parts by double insulation or by reinforced insulation, are not considered likely to become live in the event of an insulation fault.Metal parts behind a decorative cover which does not withstand the test of Clause 20 are considered to be accessible metal parts.Compliance is checked by inspection.