Circuit transmission integrity of plenum cables in a developing fire scenario

This paper presents the preliminary results of a new test program designed to measure the circuit transmission integrity of various cable designs in a fire scenarios. Cables are subjected to a novel yet simple circuit integrity measuring technique, while a localized heat source - simulating the intensity of a developing fire scenario - is applied to the cable. While this investigation only monitored changes in mutual and direct capacitance and capacitance-to-ground, other transmission parameters can be measured as well. The importance of this new test method is cables can be rapidly tested, analyzed and redesigned to withstand increasing fire intensities. Cables designed to withstand these extreme temperature environments should survive long enough to energize a fire alarm system, provide voice communication to various locations or effect an orderly shutdown of plant, as part of an energy and safety control PBX.