IEC 60317-12:2020

Overview

IEC 60317-12:2020 specifies requirements for polyvinyl acetal (including polyvinyl formal) enamelled round copper winding wire, rated Class 120. This fourth edition (2020) replaces the 2010 edition and is a technical revision that updates the Scope and adds a reference to a transformer oil resistance test method. The standard covers wire construction where the sole coating is based on polyvinyl acetal/formal resin (including permitted modified resins that retain the chemical identity and meet all wire requirements).

Key topics and requirements

• Thermal class: Class 120 requires a minimum temperature index of 120 and a heat shock temperature ≥ 155 °C. (Note: temperature index ≠ recommended continuous operating temperature.)
• Resin basis: Coating based on polyvinyl acetal / polyvinyl formal; modified resins allowed if chemical identity is retained and tests are passed.
• Nominal conductor diameters (grades):
  • Grade 1: 0.040 mm to 2.500 mm
  • Grade 2: 0.040 mm to 5.000 mm
  • Grade 3: 0.080 mm to 5.000 mm
• Test and performance clauses (specified or referenced to IEC 60317-0-1 and IEC 60851 series):
  • Dimensions and electrical resistance
  • Elongation, springiness, flexibility and adherence
  • Heat shock and cut-through resistance
  • Abrasion resistance (graded limits for specified diameters)
  • Resistance to solvents, refrigerants and transformer oil (new reference)
  • Breakdown voltage, continuity of insulation, temperature index
  • Solderability, heat/solvent bonding, dielectric dissipation, loss of mass, pin hole test
  • Packaging requirements
• Reference linkage: To be used in conjunction with IEC 60317-0-1:2013 (and Amendment 1:2019) and IEC 60851 test-method series.

Applications and who uses it

• Manufacturers of enamelled round copper winding wires and resin suppliers (formulation and quality control).
• Design and production teams for motors, transformers, inductors, coils, solenoids and other electrical/electromechanical equipment requiring Class 120 insulation.
• Test laboratories, procurement and compliance officers who verify thermal, mechanical and electrical performance (heat shock, abrasion, transformer oil resistance, etc.).
• OEMs specifying winding wire materials for reliable insulation, long-term thermal stability and compatibility with varnishes/oils.

Related standards

• IEC 60317-0-1:2013 (General requirements for enamelled round copper wire) and Amendment 1:2019
• IEC 60851 series (Winding wires - Test methods)
• IEC 60264 series (Packaging of winding wires)

Keywords: IEC 60317-12, polyvinyl acetal enamelled round copper wire, class 120, winding wire, transformer oil resistance, heat shock, nominal conductor diameter, thermal class.