IEC 60317-25:2020

Overview

IEC 60317-25:2020 specifies requirements for enamelled round aluminium winding wire, class 200, with a dual coating system: an underlying polyester or polyesterimide enamel (modifiable only if chemical identity is retained) and a superimposed polyamide‑imide enamel. This fourth edition is a technical revision that updates test notes, abrasion requirements for intermediate diameters, and limits the springiness test. Class 200 denotes a minimum temperature index of 200 and a heat shock temperature of at least 220 °C. Nominal conductor diameter ranges covered include Grade 1 and Grade 2 (see IEC 60317‑0‑3 for exact nominal diameters).

Key topics and technical requirements

• Coating system: dual-layer enamel (polyester/polyesterimide base + polyamide‑imide overcoat). Modified resins are allowed only if chemical identity and wire performance requirements are preserved.
• Thermal class: minimum temperature index 200; heat shock ≥ 220 °C.
• Dimensional and electrical properties: nominal conductor diameters and electrical resistance conform to IEC 60317‑0‑3 and its amendments.
• Mechanical / dielectric tests included or referenced:
  • Elongation, flexibility and adherence
  • Heat shock
  • Cut‑through resistance
  • Resistance to abrasion (detailed minimum forces by diameter; intermediate diameters take the next largest nominal value)
  • Resistance to solvents; breakdown voltage; continuity of insulation
  • Temperature index and resistance to refrigerants (Clause 16 limits specify extractable matter % and minimum retained dielectric breakdown voltage)
  • Solderability, heat/solvent bonding, dielectric dissipation factor, transformer oil resistance, loss of mass, pin‑hole test
• Packaging and marking requirements are included to ensure traceability and handling.

Practical applications

IEC 60317‑25:2020 is targeted at applications requiring aluminium winding wire with high thermal endurance and robust insulation, such as:

• Electric motors, generators and stator/rotor windings
• Power and distribution transformers, chokes and inductors
• High‑temperature coils in industrial equipment and HVAC compressors
• Any electrical winding where reduced weight (aluminium conductor) and class 200 thermal performance are required

Who uses this standard

• Winding wire manufacturers and enamel formulators (quality and product specification)
• Motor, transformer and coil designers (material selection and thermal design)
• Test laboratories and quality control teams (acceptance testing and type testing)
• Procurement, compliance and certification bodies (specification and conformity checks)

Related standards

• IEC 60317‑0‑3 (General requirements for enamelled round aluminium wire) and amendments
• IEC 60851 series (Winding wires - Test methods)
• IEC 60264 series (Packaging of winding wires)

Keywords: IEC 60317‑25:2020, enamelled round aluminium wire, polyesterimide, polyamide‑imide, class 200 winding wire, temperature index 200, winding wire standards.