SIST EN 3373-012:2006

Overview

SIST EN 3373-012:2006 is part of the European standard series developed by CEN for the aerospace sector. This standard specifies the characteristics of insulated, sealed in-line splices designed for crimping onto copper conductors. These in-line splices can be used with tin or silver-plated copper conductors and nickel-plated in-line splices with nickel-plated copper conductors. The products covered by this standard are suitable for environments with temperatures up to 150 °C, addressing the demanding conditions typical in aerospace applications. SIST EN 3373-012:2006 is intended to be used together with EN 3373-001, the general technical specification for this product family.

Key Topics

• Scope of Application:
  SIST EN 3373-012:2006 covers insulated and sealed in-line splices intended primarily for aerospace cable harnesses, supporting high reliability and performance at elevated temperatures.

• Temperature Range:
  The in-line splices specified maintain performance in a temperature range from −65 °C to 150 °C, making them ideal for harsh aerospace environments.

• Materials:

  • Insulating Sleeve: Made of radiation cross-linked polyvinylidene fluoride with meltable polyolefin sealing rings for optimal sealing against moisture and contaminants.
  • Crimp Barrel: Fabricated from copper alloy (per ASTM B 75), plated with tin (to ASTM B 545) or nickel (to QQ-N-290A), depending on the conductor material.

• Testing and Requirements:
  Required tests cover dielectric withstand (2,500 V DC for 1 min), insulation resistance (at least 5,000 MΩ), and resistance to rapid temperature changes, aligning with aerospace reliability standards.

• Identification and Marking:
  Components are marked using color codes on the crimp barrel, indicating their compatibility with different conductor types and sizes, as referenced in the standard's tables.

Applications

• Aerospace Wiring Harnesses:
  SIST EN 3373-012:2006 in-line splices are primarily utilized in aircraft and spacecraft electrical systems, where robust, reliable connections are critical under vibration, thermal cycling, and exposure to fluids.

• Defense and Military Vehicles:
  The standard’s high-performance requirements make these splices suitable for defense sector applications, ensuring reliability in extreme operational conditions.

• High-Temperature Industrial Applications:
  While designed for aerospace use, these in-line splices can also be applied in other industries where high temperature, vibration, and environmental sealing are required.

Related Standards

• EN 3373-001:
  General specification for terminal lugs and in-line splices for crimping on electric conductors - must be used in conjunction with Part 012.

• EN 2083:
  Covers copper and copper alloy conductors in electrical cables for the aerospace industry.

• EN 2591-305:
  Provides test methods for rapid change of temperature for aerospace electrical and optical connections.

• MIL-DTL-22520/37:
  Specifies the requirements for compatible crimping tooling.

• ASTM B 545, ASTM B 75, QQ-N-290A:
  Referenced standards for material and plating requirements.

Practical Value

Adhering to SIST EN 3373-012:2006 ensures that aerospace manufacturers, suppliers, and maintenance organizations use connectors and in-line splices that meet rigorous international standards for safety, reliability, and compatibility. The standard provides clear definitions on product characteristics, testing protocols, marking, and packaging - all critical for streamlined procurement, quality assurance, and traceability in the aerospace supply chain. Implementing this standard helps organizations demonstrate compliance with industry regulations and enhances the long-term performance of electrical systems in demanding environments.