The level in the electrodialysis tank D-1001/3 became too high, causing the transformer to trip

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Accident Name: Excessive level in the electric desalination tank D-1001/3, resulting in transformer tripping.
Time of Incident: 22:45 on January 13, 2003.
Course of the Incident: At 22:45 on January 13, 2003, the power supply duty personnel noticed abnormal current in the D-1001/3 transformer and promptly contacted the on-duty operators. The operators checked and found that clear water was visible at the fourth sight glass of D-1001/3; the control room staff discovered that the level control valve for D-1001/3 had been in the fully closed manual position for an extended period of time. The excessively high oil-water interface level caused the transformer current to rise sharply, which triggered the high liquid level protector in the electrodialysis tank and led to the transformer tripping. Prompt action was taken, and no further impact on production occurred. Cause analysis: Direct cause: 1. Before the incident occurred, the D-1001/3 level gauge was in a faulty state, and the issue was not resolved in time; therefore, during the previous shift, the water cut-off control valve was closed completely due to the low level, in order to raise the level. This is one of the direct causes of the incident. 2. The external inspection was inadequate, and a lack of responsibility prevented the timely detection of changes in the levels at D-1001/3. Additionally, the operator in the control room failed to monitor the system properly and lacked a sense of responsibility; despite knowing that the D-1001/3 level indicators were not functioning correctly, they did not check the status of the control valves for an extended period of time, failing to detect that the control valves had remained closed for so long. This was the main cause of this incident. Precautionary measures: 1. Replace the radio frequency admittance level gauge to ensure its accuracy and proper functionality. 2. Strengthen the sense of responsibility among personnel in their positions.