SIST EN 3660-016:2009

Overview

The SIST EN 3660-016:2009 standard is part of the aerospace series focusing on cable outlet accessories for circular and rectangular electrical and optical connectors. Specifically, it defines the product standard for grommet nuts, style A, available in both self-locking and non self-locking variants. These grommet nuts are designed for use with the associated electrical connector defined in EN 3660-002 and are suitable for extreme operating temperatures encountered in aerospace environments.

Key temperature classifications covered by this standard include:

• Class N: Operating temperature range from −65 °C to 200 °C
• Class W: Operating temperature range from −65 °C to 175 °C

The standard provides technical guidance on design, dimensions, materials, performance requirements, and testing protocols to ensure reliability and safety in aerospace applications.

Key Topics

• Product Range and Variants:

  • N Variant: Non self-locking version with specified dimensions and mass.
  • S Variant: Self-locking version, incorporating a locking mechanism to secure the grommet nut.

• Dimensions and Interface:

  • Comprehensive dimensions for shell sizes M12 to M37 specified with clear interface parameters.
  • Detailed technical drawings and measurement tables enable precise manufacturing and quality assurance.

• Material Specifications:

  • Class N parts made from aluminium with electroless nickel plating for enhanced corrosion resistance.
  • Class W components use aluminium with olive drab cadmium plating for optimized performance under different environmental conditions.

• Torque Requirements:

  • Defined installation assembly torque values facilitate proper installation without damaging components.
  • Coupling thread strength torque values support test protocols ensuring mechanical integrity.

• Testing and Qualification:

  • Compliance with rigorous testing regimes, including visual inspection, thermal endurance, salt mist exposure, mechanical shock, vibration, and more as detailed in EN 3660-001 and EN 2591-100.
  • Ensures durability, electrical continuity, and environmental resistance required for aerospace deployment.

• Marking and Designation:

  • Standardized marking practices guarantee traceability.
  • Designation includes material class, shell size, and locking feature for clear identification per aerospace manufacturing standards.

Applications

The SIST EN 3660-016:2009 standard is critical for the aerospace industry's electrical and optical connector systems, ensuring that cable outlet accessories like grommet nuts perform reliably under harsh and fluctuating environmental conditions. Typical applications include:

• Aircraft Wiring Harnesses: Securing cable outlets in avionics ensuring stable electrical and optical performance.
• Military and Defense Aerospace Systems: Offering ruggedized solutions for extreme temperature and mechanical stress conditions.
• Space Exploration Equipment: Providing reliable grommet nuts for connectors exposed to wide thermal cycles and challenging environments.
• Civil Aviation Electronics: Ensuring compliance with strict safety and performance criteria for passenger and commercial aircraft.

By adhering to this standard, manufacturers guarantee compatibility, safety, and long-term durability of connector accessories in aerospace systems.

Related Standards

• EN 3660-002: Index of product standards for cable outlet accessories for electrical and optical connectors – foundational to identifying compatible connectors.
• EN 3660-001: Technical specification providing general requirements and definitions for cable outlet accessories.
• EN 2591-100: Test methods for aerospace electrical and optical connections, ensuring consistency in verification procedures.
• SAE AS-85049: General specification covering electrical connector accessories, complementary for broader aerospace applications.

Keywords: SIST EN 3660-016:2009, aerospace cable outlet accessories, grommet nut style A, self-locking grommet nut, non self-locking grommet nut, electrical connectors, optical connectors, aerospace standards, cable outlet grommet, temperature class N and W, aerospace connector accessories, CEN aerospace standards.