EN 3475-403:2002

Overview

EN 3475-403:2002 is a European aerospace standard specifying test methods for electrical cables used in aircraft, focusing on the measurement of delamination and blocking in finished cables. This standard is part of the broader EN 3475 series dedicated to aerospace electrical cables and must be used in conjunction with EN 3475-100, which covers general test methods.

Delamination and blocking are critical quality parameters for aircraft electrical cables, as they affect the mechanical integrity and reliability of the insulation layers. This standard provides a reliable test procedure to ensure cables meet strict aerospace performance and safety requirements.

Key Topics

• Scope and Purpose
  The standard defines a method for evaluating the bonding quality between layers of insulation or jacketing on finished cables, ensuring there is no unwanted adhesion or separation that could compromise cable performance.

• Sample Preparation
  A cable specimen of adequate length is taken from insulated conductors or screened and jacketed cables to perform the test.

• Test Apparatus
  The test requires a mandrel of specified diameter (defined in the technical specifications of the cable) and a natural convection oven capable of reaching the temperatures specified in the applicable product standards.

• Test Procedure

  • The cable specimen is wound around the mandrel in two superimposed layers, each with 6 to 8 coils.
  • Coils must be in contact, and the conductor’s end is securely attached to prevent unwinding.
  • The assembly is placed in a natural draft oven for 6 hours at a specified temperature, then cooled at ambient temperature for at least 1 hour.

• Assessment Criteria
  After cooling, the cable must be easily unwound, with coils separable without resistance.
  Any blocking-where layers or coils stick together-or delamination, where layers separate improperly, is deemed a failure.
  For screened cables, components should separate with ease, and any flaring or bonding along the insulation or jacket is unacceptable.

Applications

• Aerospace Electrical Cable Manufacturing
  Manufacturers apply this standard to test finished cables, ensuring they meet the durability and safety criteria required for aircraft electrical systems.

• Quality Assurance and Compliance
  Aerospace suppliers and OEMs use EN 3475-403:2002 to verify product compliance before cable release, reducing risks of in-service electrical failures due to cable layer separation or jamming.

• Research and Development
  Cable designers use the test method to evaluate new insulation materials or jacket formulations, optimizing cable construction for better layer adhesion and resistance to delamination under thermal stress.

Related Standards

• EN 3475-100
  Defines general test methods that complement the specific procedures outlined in Part 403 for delamination and blocking.

• Other EN 3475 Series Parts
  The broader EN 3475 aerospace cable standards cover electrical, mechanical, and environmental testing to ensure the full qualification of aircraft electrical cable products.

• International Aerospace Standards
  While EN 3475-403:2002 is specific to European requirements, it aligns with global aerospace cable testing principles, aiding interoperability and mutual recognition of test results.

Keywords: Aerospace cable testing, electrical cable delamination, blocking test method, aircraft cable standards, EN 3475-403, cable insulation integrity, aerospace electrical systems, cable quality assurance, test methods for cables.