NEW TRENDS IN FIRE TESTING OF ELECTRICAL CABLES

ABSTRACT

This paper deals with new trends in fire testing of electrical cables. At present, the most widely used tests of electrical cables are reaction to fire tests. The cable systems powering electrical devices which have to remain operational for a certain period of time under fire conditions are additionally subjected to circuit integrity maintenance testing. New trends in cable fire tests include tests of critical heat flux, testing the effect of cable inclination, current load, voltage and frequencies to the rate of flame spread over the cable surface, and tests to assess the impact of electrical cables fire on its environment (surroundings). The impact of the electrical cables fire on its environment is expressed by the released heat (maximum heat release rate). Few tests evaluate the effect of the mutual spacing between electrical cables on the maximum heat release rate. In this paper, therefore, the influence of the mutual spacing between samples of power cable and signal cable (with the B2ca fire class) on the maximum heat release rate was assessed. Both of the examined cables showed a higher maximum heat release rate at the gap between samples equals to the cable diameter compared to the samples placed next to each other. This paper also assessed the impact of mutual spacing between investigated cables on their combustion efficiency. The obtained data suggest that the mutual spacing of samples has only negligible impact on the efficiency of combustion.

Keywords: Cone calorimeter, electrical cable, fire investigation, fire risk, reaction to fire.