Earticle

In this paper, two tests were performed using the commonly used HFIX(1.5SQ) cable for the purpose of analyzing the impact of a cable’s Cable Bend Radius and Turn on fire risk. In each test, 14A and 16A stationary electrical currents without a functioning molded case circuit breaker (MCCB) were applied respectively for 180 seconds, and then an infrared camera was used to verify the temperature characteristics and the ignition probability. The results of the tests showed that the Cable Bend Radius, within the scope of not causing physical damage to the copper wire or the cable sheath, did not have meaningful impact upon thermal accumulation. For the Turn however, there was a linear increase in the temperature of the cable even within the range of allowable current of the cable as the number of Turn increased, verifying the risk of fire from the cable sheath. Therefore, to minimize the risk of cable fires, the cable must be correctly used at all times and constant preventive actions through maintenance including regular inspection and repairs are needed.

In this paper, we studied the structure of the roast hood, predicted fire hazards through statistical data, and examined the possibility of igniting the roast hood and the variation in the potential for ignition by installing the fire prevention net. It was observed visually that fluoride caused by charcoal was sucked into the roast hood due to the negative pressure caused by the operation of the motor. In addition, the frequency of charcoal burns carried into the roast hood according to the installation of the fire prevention network was compared. This paper identifies the structural fire vulnerability of the Lost Hood, provides users and manufacturers with information on fire risk from installation of the fire prevention network, and improves the device to allow more stable use of the device, helping to infer the cause of the fire.

According to the data for the last five years, about 33.7% of the total fire causes were electricity, of which more than 81% was caused by arcs. Currently, in Korea, MCCB(Molded Case Circuit Breaker) and ELB(Earth Leakage Breaker) are legally required to be installed on distribution boards, but these do not have an arc detection function, so it is required an arc detection and blocking device, AFDD(Arc Fault Detection Device). Furthermore, in this study, data results were calculated through an arc wavelength analysis experiment of a smart AFDD(Arc Fault Detection Device) using IoT technology. If these results are continuously accumulated and data is constructed, it can be used not only as fire prevention but also as an accurate and objective point of the fire occurrence and as an identification criterion for the cause of the fire occurrence.

The production of batteries that are easier to carry, install, and easier to use than heavy products is increasing day by day, and many products made with batteries are currently being produced and sold in vehicle electric products. In the past, vehicles were often used without installing additional accessories when purchasing vehicles, but recently, additional accessories that use black box auxiliary batteries are often installed in vehicles. In particular, when a vehicle black box is installed and used as a constant power source among accessory devices, the voltage of the vehicle battery drops after parking for a long time, so the vehicle often does not start. For this reason, the number of vehicle drivers who install auxiliary batteries for vehicles is increasing to prevent a voltage drop of batteries installed in vehicles. However, it was confirmed through a press release from related agencies that some of the commercially available black box auxiliary batteries were arbitrarily changed and sold by major components such as cells inside the batteries unlike the time of certification. As the use of auxiliary batteries for vehicles increases, a number of related fires often occur, causing the vehicle to burn down or repair costs excessively. The research team of Changwon Fire Department analyzed the recent fire cases and visited related companies and related institutions and conducted a re-experiment in an environment similar to the fire conditions to investigate the risk of lithium-ion batteries charging/discharging at low temperatures.

This study reconstructed the actual fire scene and studied the risk of low-temperature ignition in the insulation material due to the heat generated when compressed refrigerant gas moves from the compressor to the condenser of the refrigerator. In addition, when the refrigerator door is open, the thermal change pattern of each part of the condenser over time was compared and analyzed. As a result of the experiment, considerable heat was generated in the process of moving from the compressor to the condenser, and when the refrigerator door was forcibly opened, the heat continued to accumulate, and it was found that the low-temperature accumulation in the insulation material could cause ignition. Through the results of this study, the ignition mechanism and fire detection options were derived to reconfigure and restore the fire scene in case of a fire due to heat storage while the refrigerator is opened.

In the event of a fire in the compartment, a hot smoke layer is formed under the ceiling. At this time, if the spray droplets are radiated downward by the operation of sprinklers, it is possible to confirm a two-sided effect that can make it difficult for residents to evacuate, although it has an excellent effect in reducing human and property damage by rapid fire suppression. In addition, in terms of fire investigation, it will have a different form from the existing fire pattern, and Scientific and objective fire investigation will be possible if the cause of human casualties is investigated through an understanding of the smoke-logging phenomenon.

In this paper, among the causes of electrical fires, the chemical properties due to thermal degradation of the wire coating, which is a polymer material, and the risk of ignition through temperature change by equivalent lifespan were analyzed. Insulated wires (HIV, 2.5SQ, single wire) used in small buildings under 500V were accelerated to deteriorate over time to produce samples for 0, 10, 20, 30, 40 years. Qualitative and quantitative analysis of insulators was performed using equipment such as strength, SEM, XRD, IR, TGA, and DSC. In addition, the temperature change by step above the allowable current was analyzed with an overcurrent tester, and through this, it was possible to confirm the risk of fire due to deterioration of insulation of old wires used in buildings. Through this study, it is possible to present the rationale for systematically introducing the replacement and repair period for old wires, and it is judged that it can be used as basic data for investigators to verify the cause of ignition due to insulation deterioration at the fire site.