ISO 10924-5:2016

Overview

ISO 10924-5:2016 specifies requirements for bolt-type circuit breakers for road vehicles with a rated voltage of 450 V d.c. This part of the ISO 10924 series defines rated current, dimensions, test procedures and performance requirements for circuit breakers with a current rating up to 300 A and an absolute breaking capacity of 6 000 A. ISO 10924-5 is intended to be used together with ISO 10924‑1 (general definitions and test requirements) and ISO 10924‑2 (user’s guide), aligning clause numbering with Part 1 except where specific modifications apply.

Key topics and technical requirements

• Rated parameters
  • Rated voltage: 450 V d.c.
  • Rated current: ≤ 300 A
  • Breaking capacity: 6 000 A
• Performance and tests
  • Operating time-rating across multiple current multiples (1.0, 1.35, 1.5, 2.0, 4.0, 6.0 × IR) with defined min/max time limits.
  • Absolute breaking capacity test at 6 000 A and U = 480 V with controlled circuit time constant.
  • Breaking capacity tests at prescribed currents and voltages.
  • Voltage-drop limits at 1.0 × IR for each rating (e.g., 0.200 V at 15 A, down to 0.070 V at 300 A).
  • Endurance, dielectric strength, pulse, climatic (−40 °C to 85 °C, Code G), vibration, shock and chemical exposure tests.
  • Strength of terminals, maximum housing temperature and no-current trip/reset temperature checks.
• Test setup and materials
  • Test cable sizes specified per rated current and thick-wall copper cables per ISO 6722-1.
  • Test fixture electrical connection resistance ≤ 1 mΩ.
  • Test arrangements in accordance with ISO 8820–7 and ISO 8820–8 for bolt and tab contacts.

Applications and users

ISO 10924-5 is targeted for professionals involved in electrically propelled and hybrid road vehicles who require robust DC protection components:

• Automotive OEMs and vehicle electrical system designers specifying high-voltage protection components.
• Circuit breaker and component manufacturers for product design, qualification and type approval.
• Test laboratories and compliance engineers performing type testing and production verification.
• Procurement and quality assurance teams ensuring suppliers meet defined performance, safety and environmental criteria.
• Integrators of battery systems and high-voltage wiring harnesses for EV/HEV applications.

Related standards

• ISO 10924-1 - Definitions and general test requirements
• ISO 10924-2 - User’s guide
• ISO 6722-1 - Road vehicle cables (test cable requirements)
• ISO 8820-7 / ISO 8820-8 - Fuse-link test fixtures and contacts
• ISO 16750-4 - Environmental/climatic loads

This standard is essential when specifying, testing or qualifying 450 V DC automotive circuit breakers to ensure consistent safety, performance and interchangeability across vehicle platforms.