BURNING CHARACTERISTICS OF POWER CABLES IN A COMPARTMENT

Abstract

Burning characteristics of power cables are one of the important parameters for the fire hazard assessment of nuclear power plants since the cables are the major sources of fire in the plants. Power cables consist one or more conductors having insulation with optional screen and jacket to provide protection from outer atmosphere. Generally PVC and XLPE is used as a jacket and insulation material which is combustible and potential source of fuel for fires, so it is necessary to understand the behavior of Cable Fire so that various fire safety measures should be taken. An experimental setup is designed and fabricated in fire research laboratory to investigate and analysis of burning characteristics of power cables in a compartment. The dimensions of the compartment are 4m x4mx 4m and having a door opening of2mxlm at the centre of one of the wall to provide natural ventilation effect during the experiments. An Exhaust System is attached to it. Experiments are carried out in two stages, in first stage cables are placed in two horizontal trays each tray consist seven cables and in second stage cables are placed in single horizontal tray in the form of bundle having 40 cables. These cables are exposed by external source of heat i.e. LPG ribbon burner. Burning characteristics like HRR, MLR,02 depletion and CO2 and CO concentration in flue gases are measured by cone calorimeter while other characteristics like flame temperature, Ilame velocity, door temperature, door velocity, temperature at ceilings, heat flux reaching at various locations such as floor, walls and roof, are measured by various instruments like thermocouples, bidirectional probe and heat flux sensors. Char length and afterburn time is measured by observation after experiment. Results obtained in this report are expected to useful to assured cable fire safety and to design fire environment.