This part of IEC 60317 specifies the requirements of solderable enamelled round copper winding wire of class 155 with a dual coating. The underlying coating is based on poly-urethane resin, which may be modified providing it retains the chemical identity of the original resin and meets all specified wire requirements. The superimposed coating is a bonding layer based on a thermoplastic resin.
NOTE 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.
Class 155 is a thermal class that requires a minimum temperature index of 155 and a heat shock temperature of at least 175 ℃.
The temperature in degrees Celsius corresponding to the temperature index is not necessarily that at which it is recommended that the wire be operated and this will depend on many factors, including the type of equipment involved.
The range of nominal conductor diameters covered by this standard is:
- Grade 1B: 0,020 mm up to and including 0,800 mm;
- Grade 2B: 0,020 mm up to and including 0,800 mm.
The nominal conductor diameters are specified in clause 4 of IEC 60317-0-1.