Overview
ISO 1467:2024 specifies performance requirements for general-purpose push-pull single-pole trip‑free circuit‑breakers used in aircraft electrical systems. The standard covers devices with an inverse time/current characteristic, rated up to and including 35 A, intended for nominal 28 V d.c. and/or 115 V single‑phase 400 Hz a.c. line‑to‑neutral circuits. ISO 1467:2024 defines design, construction, environmental and test requirements to ensure reliable overcurrent protection in aerospace applications.
Key topics and technical requirements
- Scope & ratings: Ratings up to 35 A for 28 V DC and 115 V/400 Hz AC circuits; single‑pole push‑pull, trip‑free operation.
- Design and construction: Requirements for ambient temperature/altitude, fixing type, push‑button design, surface treatment, electrical connections, fasteners and rating inviolability.
- Time/current characteristics: Definition and verification of the inverse time/current trip curve and calibration requirements.
- Performance tests: Extensive type and production tests including vibration, acceleration and mechanical shock, climatic tests, high‑voltage and insulation resistance, explosion‑proofness and magnetic influence.
- Making and breaking capacity: Tests and criteria for interrupting currents and making currents under DC and AC conditions.
- Endurance and mechanical strength: Life/cycling tests, operating force measurements, mechanical strength of terminations, push‑button and panel mounting.
- Calibration and production tests: Voltage drop, time/current characteristics, holding current, and other routine checks to ensure consistency.
- Marking and declarations: Requirements for product marking, ratings and supplier declarations for traceability and certification.
Practical applications and users
ISO 1467:2024 is essential for:
- Aircraft electrical equipment manufacturers designing or producing push‑pull circuit‑breakers.
- Avionics and power system engineers specifying overcurrent protection for 28 V DC and 115 V/400 Hz AC networks.
- Aerospace OEMs and suppliers ensuring component conformity, interchangeability and reliability.
- Test laboratories and certification bodies conducting type and production testing.
- Maintenance organizations and procurement teams requiring documented performance and marking for replacement parts.
Implementing ISO 1467:2024 helps ensure circuit‑breaker reliability under aviation environmental stresses (vibration, shock, temperature), consistent trip behavior, and regulatory compliance-critical for flight safety and system integrity.
Related standards
ISO 1467:2024 complements other international and industry standards for aircraft electrical components, electrical safety testing and environmental qualification; manufacturers should consider these alongside company and airworthiness specifications when applying the standard.