Overview
ISO 8820-8:2019 specifies requirements for fuse-links with bolt‑in contacts (Type H and J) for road vehicles, rated 450 V DC, intended for high-voltage automotive applications (current rating ≤ 400 A, breaking capacity 2 000 A). The standard defines rated currents, dimensions, marking, test procedures, performance criteria and the required test fixture design. It is to be used together with ISO 8820-1 and ISO 8820-2.
Key topics and technical requirements
- Scope & marking
- Applies to fuse-links with bolt‑in contacts (Type H, J) for 450 V DC systems.
- Fuse-links must be permanently marked with rated current, manufacturer/trademark and "450 V DC".
- Mechanical & dimensional requirements
- Detailed dimensions for Type H and Type J bolt‑in fuses are specified.
- Strength of terminals and mounting torque requirements are given.
- Electrical performance and tests
- Breaking capacity: tested at 2 000 A, 450 V DC.
- Voltage drop: measured across fuse tabs after rated current for 15 min; limits defined per type and rating.
- Transient current cycling: endurance tests (e.g., 50 000 cycles) to verify long‑term performance.
- Operating time‑rating: time‑to‑clear requirements at multiple test currents (see operating time tables).
- Temperature rise and resistance to temperature shock tests to ensure thermal reliability.
- Connection resistance and test fixture requirements (e.g., connection resistance ≤ 0.35 mΩ; fuses tested at least 150 mm apart).
- Environmental & chemical loads
- Environmental conditioning follows ISO 8820-1; chemical exposure tests use wipe procedures (no immersion).
- Test cabling
- Test cable sizes and conductor specifications refer to ISO 6722-1 (thick wall cables).
Applications and who uses this standard
- Designed for electric and hybrid vehicle high-voltage distribution and battery protection systems.
- Primary users:
- Automotive OEM electrical system designers and engineers
- Fuse and component manufacturers (Type H/J bolt‑in fuses)
- Test laboratories and conformity assessors
- Procurement and quality teams specifying HV fuse-links for EVs
- Practical applications include battery disconnect fuses, main DC power distribution protection, and high-voltage circuit protection in road vehicles.
Related standards
- ISO 8820-1 - Definitions and general test requirements (use in conjunction)
- ISO 8820-2 - Other fuse-link parts in the series
- ISO 6722-1 - Road vehicle single-core cable dimensions and test requirements
Keywords: ISO 8820-8, fuse-links, bolt-in contacts, Type H, Type J, 450 V DC, automotive fuses, high-voltage vehicle fuses, breaking capacity, voltage drop, transient cycling.