IEC 60317-18:2020

Overview

IEC 60317-18:2020 defines requirements for polyvinyl acetal enamelled rectangular copper wire, class 120. It specifies material, dimensional and performance criteria for enamelled rectangular copper winding wire with a sole coating based on polyvinyl acetal or polyvinyl formal resin (including permitted modified resins that retain the chemical identity). This fourth edition (2020) replaces the 2004 edition and Amendment 1:2009 and introduces key technical revisions including the thermal class upgrade to 120.

Key facts:

• Product: enamelled rectangular copper winding wire (sole polyvinyl acetal/formal coating)
• Thermal class: 120 (minimum temperature index 120; heat shock ≥ 155 °C)
• Conductor nominal dimensions: width 2.0–31.5 mm, thickness 0.80–10.0 mm
• Grades: grade 1 and grade 2 included
• Use in conjunction with IEC 60317-0-2:2020 for general requirements

Key topics and technical requirements

• Thermal performance: Minimum temperature index 120; heat shock temperature ≥ 155 °C.
• Dimensions and tolerances: Nominal width and thickness ranges covered; permitted width/thickness combinations referenced to IEC 60317-0-2.
• Flexibility and adherence:
  • Mandrel winding test: bending flatwise and edgewise; mandrel diameters set as multiples of wire width/thickness (see standard Table 1).
  • Adherence (formerly stretching) test: wire stretched by 20% or until break; loss of adhesion requirement specified in the standard.
• Electrical properties: Electrical resistance, breakdown voltage at elevated temperature (120 °C) and other electrical tests per IEC 60317-0-2.
• Tests marked inappropriate or under consideration: several tests such as resistance to abrasion, solderability, continuity of insulation are listed as “inappropriate” or have test requirements under consideration (e.g., cut-through and transformer oil resistance details).

Applications and who uses this standard

Typical users and applications:

• Winding wire manufacturers - to design, produce and certify polyvinyl acetal enamelled rectangular copper wire to Class 120.
• Electrical OEMs and designers - for motors, transformers, inductors, coils, generators and other wound electrical equipment specifying rectangular enamelled wire.
• Test laboratories and quality assurance - to validate adherence, thermal and electrical performance per standard requirements.
• Procurement and standards compliance teams - to specify acceptable wire grades, dimensions and test regimes.

Keywords: IEC 60317-18:2020, polyvinyl acetal enamelled rectangular copper wire, class 120, winding wire, enamelled rectangular copper wire, adherence test, mandrel winding, temperature index 120, heat shock 155 °C.

Related standards

• IEC 60317-0-2:2020 - General requirements for enamelled rectangular copper wire (mandatory companion).
• IEC 60851 series - Test methods for winding wires.
• IEC 60264 series - Packaging of winding wires.