SIST EN 2349-409:2009

Overview

SIST EN 2349-409:2009 is a European standard developed by the AeroSpace and Defense Industries Association of Europe (ASD-STAN) under CEN. It specifies the test methods and requirements for assessing the ozone resistance of relays and contactors used in aerospace applications. This document is part 409 of the Aerospace series standards focused on relays and contactors and must be used together with the general requirements defined in EN 2349-100.

This standard ensures that aerospace electrical components can withstand ozone exposure without degradation, thus guaranteeing reliability and durability in ozone-rich environments encountered during flight and ground operations.

Key Topics

• Scope: Defines testing procedures to verify the capability of relays and contactors to resist ozone exposure.
• Test Methodology:
  • Relays/contactors are mounted according to product specifications.
  • Devices are exposed in an open air-circulating chamber.
  • Ozone concentration during exposure is maintained between 0.010% and 0.015% by volume.
  • Exposure duration is 2 hours at room temperature.
• Pass/Fail Criteria: No signs of damage or deterioration shall be observed after the ozone exposure test.
• Normative References:
  • EN 2349-100: General requirements for aerospace relays and contactors.
  • EN 2349-201: Visual inspection requirements for aerospace relays and contactors.
• Compliance: This standard is mandatory for aerospace manufacturers and suppliers within CEN member countries, ensuring consistent quality levels.

Applications

The SIST EN 2349-409:2009 standard applies primarily to:

• Aerospace Electrical Systems: Ensuring the operational reliability of relays and contactors in commercial and military aircraft.
• Relay and Contactor Manufacturing: Guiding manufacturers in validating their products’ ozone resistance to meet aerospace demands.
• Quality Assurance and Testing Facilities: Providing a benchmark test procedure for ozone exposure to certify product durability.
• Maintenance and Inspection: Facilitating ongoing evaluation of relay and contactor condition related to ozone exposure in service environments.

By adhering to this standard, aerospace component manufacturers can enhance product longevity and safety, reduce in-service failures, and maintain compliance with international aerospace quality regulations.

Related Standards

To fully implement ozone resistance testing and quality assurance for aerospace relays and contactors, SIST EN 2349-409:2009 should be considered alongside related standards such as:

• EN 2349-100: Aerospace series - General requirements and test procedures for relays and contactors. Provides foundational guidance on design and testing beyond ozone resistance.
• EN 2349-201: Aerospace series - Visual inspection procedures for relays and contactors. Prescribes inspection techniques relevant after ozone exposure testing.
• Other Aerospace Electrical Equipment Standards: Complementary standards covering broader aspects like vibration resistance, humidity, temperature, and electrical characteristics.

Summary

SIST EN 2349-409:2009 establishes a clear, standardized method to verify the ozone resistance of aerospace relays and contactors, ensuring these critical components maintain integrity in oxidizing atmospheres. Compliance with this standard supports operational safety and reliability in aerospace electrical systems under ozone exposure conditions.

Key benefits include:

• Enhanced product resilience in aerospace environments
• Uniform testing practices across manufacturers and countries
• Improved quality control and risk mitigation for aerospace electrical equipment

For aerospace manufacturers and suppliers, adopting SIST EN 2349-409:2009 is essential for meeting regulatory requirements and delivering durable, high-performance relays and contactors fit for modern aviation challenges.