SIST EN 2349-301:2009

Overview

SIST EN 2349-301:2009 is a European aerospace standard that specifies the requirements and test procedures for pick-up and drop-out voltage in relays and contactors used in aerospace applications. Developed by the AeroSpace and Defense Industries Association of Europe (ASD-STAN) and ratified by CEN, this standard ensures consistency and reliability in the electrical performance of critical aerospace components.

The standard must be used together with EN 2349-100, which covers general requirements and test procedures for relays and contactors in aerospace systems. EN 2349-301 focuses specifically on measuring the voltage levels at which relays and contactors activate (pick-up voltage) and deactivate (drop-out voltage), crucial parameters for ensuring device performance in aeronautical systems.

Key Topics

• Pick-up Voltage Testing

  • The standard defines a method for gradually increasing voltage applied to the relay or contactor coil until the device actuates.
  • Devices must be de-energized for 30 minutes prior to testing to prevent coil overheating.
  • Tests include monitoring contact switching positions using indicating devices.
  • Qualification tests require evaluation in multiple orientations (six degrees of freedom) to simulate operational conditions.

• Drop-out Voltage Testing

  • Specifies procedures for gradually decreasing voltage to determine the point at which the relay or contactor releases.
  • Similar pre-test coil de-energization and use of indicating devices apply.
  • Testing also involves multiple axes to ensure robust operational reliability across different orientations.

• Mounting and Wiring

  • Proper electrical wiring and mounting conforming to EN 2349-100 is mandatory for both tests.

• Test Criteria

  • The relay or contactor must pick up at the rated voltage specified in the respective product standard.
  • Drop-out voltage must occur within specified ranges to guarantee proper device functionality.

Applications

SIST EN 2349-301:2009 is essential for aerospace engineers and manufacturers who design, produce, and qualify relays and contactors used in aerospace electrical systems. Ensuring correct pick-up and drop-out voltages supports:

• Aircraft electrical system reliability: Accurate voltage thresholds prevent unintended switching and maintain operational consistency.
• Safety in avionics: Reliable operation of relays and contactors reduces failure risks in critical electrical circuits.
• Component qualification and certification: Used in testing protocols required for aerospace compliance and certification processes.
• Design optimization: Helps engineers select components that meet stringent aerospace voltage performance requirements.

This standard benefits aerospace manufacturers, testing laboratories, and quality assurance professionals focused on electrical components used in aviation, space vehicles, and defense aerospace systems.

Related Standards

• EN 2349-100: General requirements and test procedures for aerospace relays and contactors - foundational to apply EN 2349-301.
• Aerospace electrical standards governing reliability, environmental conditions, and operational performance for electronic components.
• Other parts of the EN 2349 series, detailing specific testing methods and requirements relevant to aerospace electrical devices.

By adhering to SIST EN 2349-301:2009, companies ensure that the aerospace relays and contactors operate reliably within required electrical parameters, enhancing system safety and performance in critical aerospace applications.