Overview
ISO 8668-6:1994 - "Aircraft - Terminal junction systems - Part 6: Detail specification for type 4 system" is an ISO detail specification that defines the design, ratings and test requirements for a Type 4 Terminal Junction System (TJS) used in aircraft wiring and airframe electrical installations. It is intended to be read in conjunction with ISO 8668-1 (Characteristics) and ISO 8668-2 (Tests) and includes component specification sheets (Annex A), qualification samples (Annex B) and contact test methods (Annex C).
Key topics and requirements
- Scope and description
- Defines a family of multicontact connecting devices: bussing modules, distribution and electronic modules, grounding junctions, in-line wire and electronic junctions, racks, mounting brackets, sealing plugs and tools.
- Contacts are removable female crimp-type; modules are removable from anodized aluminum frames with unique contact identification.
- Electrical ratings
- Contact current ratings specified by contact size (sizes 22, 20, 16, 12).
- Working voltage: nominal 600 V at sea level; 300 V at high altitude (values in the standard); proof voltages also specified.
- Contact resistance and insulation resistance limits are defined and referenced to ISO 8668-2 test methods.
- Environmental and mechanical requirements
- Operating temperature range –65 °C to +200 °C.
- Altitude, low-pressure immersion, vibration, mechanical shock, climatic, salt spray and endurance tests are specified using ISO 8668-2 procedures.
- Resistance to fluids, magnetic effects and flammability are addressed.
- Materials, tools and accessories
- Frames: anodized aluminum alloy; contacts and sealing plugs per annex sheets.
- Crimp joints must comply with ISO 1966; insertion/extraction and crimping tools are specified in annexes.
- Qualification & production tests
- Detailed type-approval test program, production 100% acceptance tests and batch sampling, recurring quality control schedules and Declaration of Performance requirements.
Applications
- Design and manufacture of aircraft wiring harnesses, terminal junction frames, bus distribution blocks, grounding systems and electronic junction blocks.
- Use in airframe and avionics interconnecting wiring systems where environmental ruggedness and interchangeability are required.
- Standard for integration of modular removable junctions in racks and cable looms.
Who should use this standard
- Avionics and aircraft electrical engineers
- Connector and module manufacturers
- Test laboratories performing type approval and production tests
- OEM procurement and quality engineers specifying TJS components for aircraft
Related standards
Keywords: ISO 8668-6, Terminal Junction System, TJS, aircraft connectors, crimp contacts, avionics wiring, type 4 system, terminal junction specification, aerospace electrical standards.
