ISO 1467:2024
General purpose push-pull single-pole circuit-breakers for aircraft — Performance requirements

Standard No.

ISO 1467:2024

Release Date

2024

Published By

International Organization for Standardization (ISO)  IX  /  ISO

Latest

ISO 1467:2024

Introduction

Analysis of core requirements of the standard

ISO 1467:2024 standard specifies the performance requirements of push-pull single-pole circuit breakers with a rated current of ≤35A in aviation applications. The main technical features include:

Technical dimensions	DC system (28V)	AC system (115V/400Hz)
Breaking capacity category	1.5D/3D/6D (up to 6000A)	1A/2A/3.5A (up to 3500A)
Operating force requirements	Closing force 3.5-55N / Tripping force 5-40N
Environmental adaptability	-55℃ to +125℃ / Altitude ≥22000m

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Key technical innovations

Compared with the first edition of the standard in 1973, the 2024 edition has major updates:

• Extended temperature range: Newly added +125℃ high temperature operating requirement
• Mechanical strength upgrade: Terminal tensile strength increased to 45N, torque requirement 1.8N·m
• Test method optimization: Added continuous monitoring under 90% load conditions in vibration testing

Typical application scenarios

In the power distribution system of a certain type of regional passenger aircraft, a 25A push-pull circuit breaker compliant with ISO 1467 is used to achieve:
1. Overload protection of the generator output circuit
2. Manual disconnection of the avionics equipment power supply circuit
Actual tests show that at a low temperature of -55℃, it can still ensure an accurate tripping time of 0.035-2s at 200% current

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Implementation suggestions

1. Selection and matching: Select the -55/+70℃ or -55/+125℃ version according to the actual operating temperature
2. Installation specifications: Use the panel opening size specified in ISO 530 to ensure that the operating button is installed vertically
3. Test verification: Production testing must include high-voltage testing (≥1500V AC) as specified in 13.6

Technology evolution analysis

Standard development reflects three major trends in aviation electrical systems:
1. High reliability: Added 10,000 mechanical life test requirements
2. Lightweight: Allows the use of 22AWG thin wires that comply with ISO 2635
3. Intelligence: Requires recording of accurate tripping time of 20/30 times the rated current