Investigation of ethylene plant emergency shutdown system failure due to false signal.

PT. Chandra Asri is the largest petrochemical company in Indonesia. Operations and production require a reliable electrical power supply to ensure smooth operation and safety. The electric power system is supplied by PT. PLN through a 150 kV system in parallel with the gas turbine as a captive generation. The electrical system is integrated with the Emergency Shutdown System (ESD) to protect equipment and people from various disturbances that can cause damage and work accidents. ESD should only work if something happens according to a logic diagram that has been designed as needed. One time, the factory experienced a disturbance that came from the AC power signal being off, thus activating the Emergency Shutdown System (ESD). The power outage caused production to stop, causing huge losses. The incident report on the Distributed Control System (DCS) stated that there was no interruption of the electrical power supply from either PLN or captive generation. This condition cannot occur based on the logic diagram in the ESD system. Therefore, it is necessary to thoroughly analyze and investigate the main causes of total power outages in the company. Investigating the root cause of the active ESD of the ethylene plant using brainstorming techniques and focus group discussions involving operators, technicians, engineers, and outside experts. Analysis of the main causes of failure using fishbone diagram techniques related to the problem, phenomenon, principle, and parameter (4P), men, machines, materials, methods, and the environment (4M+1E). The results of the investigation stated that there was DC power supply activity that caused the DC charger to turn off. This de-energizes the interposing relay which is used as the ESD signal. [ABSTRACT FROM AUTHOR]