prEN 3475-604

Aerospace series - Cables, electrical, aircraft use - Test methods - Part 604: Resistance to dry arc propagation

Publication date:   Oct 17, 2024

Scope

This document specifies a method for appraising the behaviour of cable insulation when an electric arc is initiated and maintained by two (2) powered cables rubbing against a blade.
This document is intended to be used together with EN 3475-100.
The primary aim of this test is:
- to produce, in a controlled fashion, continuous failure effects, which are representative of those, which can occur in service when a typical cable bundle is damaged by abrasion such that electrical arcing occurs, both between the cables and conductive structure; and
- to examine the aptitude of the insulation to track, to propagate electric arc to the electrical origin.
Originally defined for 115 VAC network, this test also proposes conditions for 230 VAC network. However, for 230 VAC test condition only, the test EN 3475-605 can overrule and be applied as test governance as it has been demonstrated that test EN 3475-605 is more stringent, repeatable and reproductible.
Unless otherwise specified in the product standard, only 115 VAC conditions are satisfied.
Six levels of prospective fault current have been specified for concerned cable sizes (see Clause 8). It is agreed that larger sizes need not be assessed since the short-circuit phenomenon becomes dominant at low line impedances.
Unless otherwise specified in the technical/product standard, sizes 002, 006 and 020 cable are assessed.