Overview
ISO 8820-9:2014 - Road vehicles - Fuse-links - Part 9 specifies fuse-links with shortened tabs (Type K) for use in road vehicles. The standard defines rated current classes, test procedures, performance requirements and dimensional specifications for Type K fuse-links intended for low-voltage automotive applications (rated voltage 58 V, current ≤ 30 A, breaking capacity 1 000 A). ISO 8820-9:2014 is intended to be used together with ISO 8820‑1 (definitions & general tests) and ISO 8820‑2 (user’s guide).
Key topics and technical requirements
- Scope and ratings
- Applicable to Type K fuse-links: rated voltage 58 V, current rating up to 30 A, breaking capacity 1 000 A.
- Performance and test sequences
- Prescribes complete test sequences (clause numbering aligned with ISO 8820‑1) including dimensional checks, marking, voltage-drop, transient current cycling, operating time, current steps and breaking-capacity tests.
- Requires visible evidence of a blown fuse element after operation.
- Electrical limits
- Voltage drop and connection resistance are measured across defined points; maximum voltage-drop limits depend on fuse rating (typically in the 120–250 mV range across ratings).
- Time-current characteristics
- Operating time and current step requirements (e.g., 1.1×, 1.35×, 1.6× rated current tests) with specified minima and maxima for fuse clearing times.
- Breaking capacity
- Verified at 1 000 A using specified cable sizes and a test dummy geometry defined in the standard.
- Mechanical and environmental
- Terminal strength tests (defined forces and maximum deformation), climatic, chemical and mechanical load conditions.
- Marking and colour coding
- Colour-coding by current rating is specified (examples: 10 A = red, 15 A = blue, 30 A = green) to aid identification.
- Dimensions and designation
- Full dimensional drawings and tolerances for Type K fuses and test fixtures. Example designation: Fuse-link ISO 8820–K–15.
Practical applications and users
Who uses ISO 8820-9:2014:
- Automotive OEMs and Tier‑1 electrical designers selecting and specifying blade fuses for low-voltage circuits.
- Fuse and fuse-holder manufacturers ensuring interchangeability and compliance.
- Test laboratories validating fuse performance (voltage drop, breaking capacity, environmental robustness).
- Quality and regulatory teams documenting component compliance for vehicle approvals.
Practical benefits:
- Ensures consistent electrical and mechanical performance for Type K automotive fuses.
- Supports safe overcurrent protection design for wiring harnesses and low-voltage vehicle electronics.
- Facilitates component interchangeability and supplier qualification.
Related standards (applicable)
Keywords: ISO 8820-9:2014, Type K fuse-links, automotive fuse standards, road vehicle fuses, fuse voltage drop, breaking capacity 1000 A, fuse dimensions.
