This part of IEC 60317 specifies the requirements of enamelled rectangular copper winding wire of class 120 with a sole coating based on polyvinyl acetal or polyvinyl formal resin, which may be modified providing it retains the chemical identity of the original resin and meets all specified wire requirements NOTE1 A modified resin is a resin that has undergone a chemical change, or contains one or more additives to enhance certain performance or application characteristics. NOTE2 Polyvinyl acetal is a general name for a family of thermoplastic vinyl resins produced by the condensation of polyvinyl alcohol with an aldehyde. Examples are polyvinyl acetal, polyvinyl formal and polyvinyl butyral. The range of nominal conductor dimensions covered by this standard is: width: min. 2,0 mm max. 16,0 mm; thickness: min. 0,80 mm max. 5,60 mm. Wires of grade 1 and grade 2 are included in this specification and apply to the complete range of conductors. The specified combinations of width and thickness as well as the specified ratio width/thickness are given in IEC 60317-0-2:2019.