Effect of deposition of combustible matter onto electric power cables

Abstract

A layer of dust could ignite if the critical ignition condition were to be reached. This depends, as we shall see later, on the ambient temperature, the thickness and configuration of the dust layer, the electric heating by the current etc.
The dust layer, if not extremely reactive, might cause failure of the cable by overheating since the extra insulation of the dust layer is not allowed for in standard tables, nor is the heat generated by normal decomposition of the dust.

One can thus envisage two extreme types of failure, ignition of the dust before cable failure and cable failure before the dust ignites due to its insulating and thermogenetic properties.

The primary question raised was whether any effects of this type could occur for a reasonable thickness of dust layer; i.e. would it be km, m or cm for a reasonable cable installation?