(A) study on the fire retardant performance of non-class 1E cables depending on the ambient temperature condition surrounding the facilities for flame test of cables

Abstract

Electrical cables are the major components of combustibles used in nuclear power plants. Therefore, fire retardant performance for electrical cables used widely in nuclear power plants had been verified according to IEEE 383 standard, which describes the requirements for the flame test for cables

however, IEEE 383 standard provides only the lowest ambient temperature (5$^\circ C$) surrounding the facilities for the flame test. To analyze the effect of the ambient temperature on fire retardant performance of cables, flame tests with two kinds of Non-Class 1E cables were conducted under the condition with the seasonal ambient temperatures surrounding the facilities. As the result of flame tests, it is found the burning length of cables does not increase in proportionally to the ambient temperature rising

but the burning length of cables decreases significantly in the winter season with the lowest ambient temperature.