IEC 60317-27-1:2020 specifies the requirements of paper tape covered round copper winding wires. This covering consists of two or more layers of paper tape and is primarily intended for winding coils for oil immersed transformers. The range of nominal conductor diameters covered by this document is:– 0,500 mm up to and including 5,000 mm.The nominal conductor diameters are specified in Clause 4 of IEC 60317-0-1:2013.The paper tapes included in this document are restricted to those specified in IEC 60554-1 and IEC 60554-3-5.