SIST EN 3475-502:2004

Overview

EN 3475-502:2002 is a European aerospace test method for electrical cables used in aircraft. Published as part of the Aerospace series and prepared by AECMA (now within CEN technical adoption), this standard specifies a method to evaluate an insulation’s resistance to propagation of a surface notch (notch propagation). It is intended to be used together with EN 3475-100 (general test method requirements) and references the EN 3475-302 voltage proof (dielectric) test.

Key topics and requirements

• Scope: Defines a practical test procedure for assessing whether a surface notch in cable insulation or jacket will propagate into a puncture under mechanical deformation and electrical stress.
• Specimen preparation:
  • Cable specimen length: 500 mm.
  • Both ends stripped over 25 mm.
  • A 90° cut (notch) is made at the specimen centre to the depth specified in the applicable product standard, using a razor blade mounted in a depth-controlled holder (blade holder).
• Test apparatus: Uses a controlled blade holder and a mandrel sized to the cable under test (see standard figures for details).
• Test method:
  • The notched specimen is wound at least 360° around a mandrel whose diameter is six times the maximum cable diameter specified in the product standard, with the notch on the outside.
  • After winding and removal, the specimen must withstand the voltage proof test defined in EN 3475-302.
• Acceptance criteria: No puncturing of the insulation or jacket is allowed (i.e., the notch must not propagate to a puncture under the combined mechanical/electrical test conditions).

Applications and practical value

• Ensures the mechanical and electrical integrity of aircraft cable insulation when damaged by surface notches.
• Used to qualify materials and cable designs, verify production quality, and support safety assessments for wiring installations in aircraft.
• Helps manufacturers and test laboratories detect insulation formulations or constructions prone to notch propagation under operational stresses, reducing in-service electrical failures.

Who should use this standard

• Cable and wire manufacturers for product qualification and quality control
• Aerospace OEMs and system integrators for procurement specifications and acceptance testing
• Independent test laboratories performing certification or compliance testing
• Design and reliability engineers assessing wiring-system durability

Related standards

• EN 3475-100 - Tests: General (to be used together with EN 3475-502)
• EN 3475-302 - Voltage proof test (referenced as the dielectric test following the notch procedure)

Keywords: EN 3475-502, notch propagation, aerospace cables, insulation resistance, test method, voltage proof test, aircraft electrical wiring, CEN, AECMA.