Overview
ISO 2032:1973 defines the requirements for heat-resisting equipment wires for aircraft, focusing on hook-up wires used in the internal wiring of aircraft meters, panels, and electrical/electronic equipment. This international standard ensures that aircraft wiring meets strict thermal and electrical performance criteria, enabling safe, reliable operation in demanding aerospace environments.
The specification covers three classes of wires:
- Type A: Suitable for voltages up to 250 V r.m.s.
- Type B: Suitable for voltages up to 600 V r.m.s.
- Type C: Suitable for voltages up to 1,000 V r.m.s.
Materials include annealed high-conductivity copper conductors, often silver-coated, and insulation materials such as polytetrafluoroethylene (PTFE) or equivalents. Wires may optionally include a metal braid for additional mechanical and electromagnetic protection.
Key Topics
Construction and Materials
- Conductors are made from stranded or bunched annealed copper wires coated with silver or an equivalent metal.
- Insulation must be uniform, circular in cross-section, and resistant to aviation fluids, temperature extremes (-75 °C to 200 °C stabilized conductor temperature), light, and moisture.
- Metal braids, when used, must be closely fitted and applied spirally without joints or splices in the complete braid.
Performance Requirements
- Wires must resist thermal aging, moisture, and environmental challenges typical in aircraft operation.
- The conductor and insulation must withstand bending at low temperatures (not below -50 °C for flexing).
- Insulation and overall wire construction must prevent combustion.
- Electrical resistance and dimensions are tightly controlled to ensure consistent quality and safety.
Testing and Certification
- Type tests, including high-temperature aging, insulation tests underwater, bend tests, and flame resistance, are mandatory before certification.
- Routine production testing covers conductor resistance, spark tests, voltage withstand, solderability, and insulation stability.
- Marking and labeling requirements include clear identification of wire type, size, manufacturer, and batch information to ensure traceability.
Applications
ISO 2032:1973 wires are specifically designed for:
- Internal wiring of aircraft electrical meters, control panels, and avionics equipment
- Fixed installations inside aircraft cabins, fuselage, and equipment bays where high thermal resistance and electrical performance are critical
- Aerospace environments requiring wiring that maintains integrity under continuous high temperatures without supporting combustion
- Aircraft maintenance and manufacturing where standardized, tested, and certified hook-up wiring improves safety and reduces failure risk
This makes the standard highly relevant for aerospace manufacturers, airlines, maintenance organizations, and regulatory compliance authorities.
Related Standards
For complementary guidance and related aerospace wiring standards, consider:
- ISO 2436 - Methods of test for aircraft wires
- IEC standards on annealed copper conductors and electrical insulation materials
- Other ISO standards covering fire resistance and wiring safety in aerospace applications (to be developed or referenced outside ISO 2032:1973)
Using ISO 2032:1973 alongside these related documents ensures comprehensive compliance with aviation industry best practices, promoting aircraft safety and reliability through standardized wire construction, testing, and performance.
Keywords: ISO 2032:1973, heat-resisting wires, aircraft wiring, hook-up wires, aerospace electrical wires, copper conductors, PTFE insulation, aircraft wire testing, thermal resistance, metal-braided wire, aviation wiring standards.