이승구  김두현  김성철

Vol. 39,  No. 6, pp. 1-9, Dec.  2024
10.14341/JKOSOS.2024.39.6.1

FTA(fault tree analysis) MCS(minimal cut set) FV(Fussell Vesely) importance frying process manufacturing Failure rate

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This study aims to obtain a minimal cut set (MCS) from fault tree analysis (FTA), a quantitative risk assessment technique for electrical equipment in the food manufacturing industry. For this purpose, quantitative data on potential failure mode percentages (%) obtained from the RAIC FMD2016 database was employed, along with failure rates provided in the non-electronic parts reliability data (NPRD) and electronic parts reliability data (EPRD) libraries. Additionally, a fault tree diagram was constructed. For the MCSs derived here, the probability of failure for electrical equipment used in the frying process system was calculated based on the accumulated importance value (ACC) of the MSC. The potential failure mode accounted for 53% of the failure probability, which was found in the motor, the switch mode power supply (SMPS), the heater, the molded case circuit breaker (MCCB), and the magnetic contactor (MC). The main part of the frying system included the motor and the heater, while the switch-type MC used to operate it had been switching on the system frequently due to unwanted connections formed via foreign objects, thereby generating a fault current. This fault current also affected the motors, the heaters, and all other components in the system that were supplied with current at the rated value. This explained the previous cases where these parts caught fire. In addition, it was confirmed that issues with alarms and monitoring systems occurred in the event the SMPS failed since this component supplied power to various sensors and boards that checked the failure or regular operation of the entire setup. The defect tree analysis approach proposed in this study can be applied not only to the food industry but also to various other manufacturing industries.