ISO 8820-8:2019

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.