ISO 10924-3:2025

Overview

ISO 10924-3:2025 - "Road vehicles - Circuit breakers - Part 3: Miniature circuit breakers with tabs (Blade type), Form CB11" specifies the design, ratings, test procedures, performance requirements and dimensions for miniature blade‑type circuit breakers intended for road‑vehicle electrical systems. The standard applies to breakers with rated voltages of 14 V and/or 28 V, current ratings ≤ 30 A and an interrupting (breaking) capacity of 2 000 A for use in nominal 12 V and/or 24 V vehicle systems. It covers multiple device functions (electric reset, automatic reset, manual reset and switchable) and is intended to be used together with ISO 10924‑1 and ISO 10924‑2.

Key Topics

• Rated parameters: voltage classes (14 V / 28 V), current ratings up to 30 A, breaking capacity 2 000 A.
• Device forms and functions: Form CB11 blade/tab miniature circuit breakers with various reset types.
• Test procedures and performance: specified sequences and test plans (voltage drop, absolute breaking capacity, breaking capacity, endurance, operating time‑rating, current steps, no‑trip/reset temperature).
• Environmental and mechanical requirements: temperature range −40 °C to 85 °C (Code G per ISO 16750‑4), climatic, chemical, vibration, shock and free‑fall tests.
• Safety and electrical integrity: dielectric strength tests, maximum housing temperature limits, terminal strength and connection resistance requirements (test fixture connection resistance ≤ 0.8 mΩ).
• Dimensions, marking and colour coding: tab dimensions, designation examples and a colour code table linking rated current to colour (e.g., 5 A tan/light brown, 10 A red, 30 A green).
• Test cables: specified conductor cross‑section sizes for comparative testing by rated current.

Applications

• Automotive electrical component manufacturers designing blade‑type miniature circuit breakers to meet international vehicle standards.
• OEMs and Tier‑1 suppliers specifying protective devices for 12 V and 24 V vehicle electrical systems.
• Test laboratories and certification bodies executing standardized electrical, mechanical and environmental testing.
• Vehicle electrical engineers and procurement teams evaluating breaker performance versus miniature fuse‑links (ISO 8820‑3) for comparable applications.

Practical Value

Implementing ISO 10924‑3:2025 ensures consistent performance, interchangeability and safety of blade‑type miniature circuit breakers in road vehicles. It helps manufacturers meet regulatory and OEM requirements, enables reliable overcurrent protection design, and provides defined test methods for supplier qualification and component validation.

Related Standards

• ISO 10924‑1 - Definitions and general test requirements
• ISO 10924‑2 - Guidance for users
• ISO 8820‑3 - Fuse‑links with tabs (blade type)
• ISO 6722‑1 - Single‑core cable dimensions and tests
• ISO 16750‑4 - Climatic loads for vehicle electrical/electronic equipment

Keywords: ISO 10924‑3:2025, miniature circuit breakers, blade type, Form CB11, road vehicles, automotive circuit breakers, breaking capacity, voltage drop, dielectric strength.