SIST EN 2349-405:2009

Overview

EN 2349-405:2006 specifies a method to check the capability of aerospace relays and contactors to withstand exposure to fluids. This part is intended to be used together with EN 2349-100 (general requirements) and references the established fluid-resistance test method in EN 2591-315. The standard supports consistent evaluation of fluid-induced degradation and helps maintain electrical system reliability in aerospace applications.

Key Topics

• Scope and purpose: Defines the objective of verifying fluid resistance for relays and contactors used in aerospace equipment.
• Mounting and preparation: Components shall be wired in accordance with the product standard. For plug-socket arrangements, unused contact positions must have blanking plugs fitted.
• Test method reference: The fluid exposure procedure is carried out in accordance with EN 2591-315; product-specific temperature limits apply as defined by the applicable product standard.
• Acceptance criteria: Post-test inspection is carried out per EN 2349-201 (visual inspection). The requirement is that there shall be no signs of attack or corrosion.

Applications

This standard is relevant for manufacturers, test laboratories and engineering teams involved in the design, qualification and maintenance of aerospace electrical components. Practical applications include:

• Ensuring relays and contactors maintain performance and safety when exposed to hydraulic fluids, cleaning agents or other operational fluids encountered in aircraft environments.
• Supporting procurement and qualification processes by providing a clear, harmonized test approach for fluid resistance.
• Informing maintenance and inspection criteria where fluid exposure is a known risk, helping to prevent corrosion-related failures and improve system reliability.

Related Standards

• EN 2349-100 - General requirements for relays and contactors (use together with Part 405).
• EN 2349-201 - Visual inspection procedures referenced for post-test assessment.
• EN 2591-315 - Fluid resistance test methods; Part 405 specifies that the test is carried out in accordance with this document.

Practical value

Following EN 2349-405:2006 ensures a standardized approach to assessing fluid resistance, reducing variability between test labs and manufacturers. Using the referenced methods and inspection criteria helps protect electrical contacts from corrosion, supports compliance with aerospace quality systems, and contributes to the overall safety and longevity of aircraft electrical systems.

Keywords: relays, contactors, fluid resistance, aerospace, EN 2349-405, EN 2349-100, EN 2591-315, corrosion, test procedures.