I’d like to share an accident case that occurred in my company in 2012

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Report on the incident caused by closing the grounding switch while the system was still under voltage on September 10, 2012: power outage across the entire plant, equipment damage, and disruption of heating services. Incident details: At 8:20 a.m. on September 10, 2012, the coal transportation team leader submitted a request for a power outage so that the new crusher could be maintained and cleaned. The power outage notice was signed; since the keys to the 10KV control room were taken by the maintenance staff for inspections, it was agreed with the coal transfer shift leader to give a telephone notification after the power was cut off. At 8:35, the maintenance staff brought the keys; while filling out the operation ticket, the electrical assistant operator xx took the keys and left. At 8:37, it was discovered that there was an abnormality on the generator control panel – the power factor was fluctuating greatly, the active load dropped to zero, and the generator was disconnected from the system. Hearing abnormal noises in the control room, xx rushed over to report that the grounding switch had been closed while the system was still under voltage; a fire broke out in the 10kV switchroom, causing a power outage throughout the plant. After the accident, the boiler operator immediately reset the power equipment and shut down the boiler ； The turbine operator handled the situation as an emergency shutdown: they closed the isolation valves before and after the main valve supplying steam for internal use to the deaerator, disabled the interlocks of all equipment, reset all switches, started the DC oil pump, closed the main steam valve, manually shut down the electric valve for the first extraction stage, and closed the outlet of the No. 2 feed water pump, thereby causing an emergency shutdown due to a loss of vacuum; all other normal shutdown procedures were then followed ； Electrical personnel conducted an inspection and found that the switches on the high-voltage and low-voltage sides of the #2 main transformer, as well as xxxxxxxx, had not tripped. They manually separated the low-voltage side and the high-voltage side switches of the #2 main transformer, while taking appropriate safety precautions. At around 8:40, the company organized operators and maintenance staff to carry out fire-fighting efforts in the 10KV control room. Thick smoke and toxic gases generated by the burning cables made it difficult to carry out these rescue operations, and the fire was extinguished around 10:50. Restoration of power supply was attempted, but the start of the DC oil pump led to a shortage of DC power; furthermore, the contactors in the 110kV control cabinet were rusted and would not operate, which hindered the restoration of power supply. Power supply was restored around 13:00; the boiler feed pump was started at 13:20, and the boiler was operating normally by 15:50, with the steam turbine supplying steam outward as usual. At 22:10, Generator #1 was connected to the grid. Accident losses: 1. Control cabinets for pumps No. 3 and No. 3#. 2. Crusher control cabinet. 3. High-voltage frequency converter (control cabinet, power cabinet). 4. A disruption in steam supply from the external network leads to shutdowns of heating users and poses safety risks. Cause of the accident: Through accident analysis meetings and an assessment of the conditions at the accident site, the causes of the accident are as follows: 1. The operators failed to strictly comply with the company’s rules regarding the use of work orders and supervision procedures, and carried out operations in violation of regulations (operating without a work order, and operating without supervision). 2. The locking reliability of the high-voltage switchgear does not meet the requirements. 3. The reason for the step-over trip was that the contactor in the 110KV control cabinet had rusted and would not operate; furthermore, the protection setting notification forms were not followed strictly. 4. The lack of gas masks and high-power emergency lighting slows down rescue efforts. 5. The safety department and workshops fail to implement proper safety management, resulting in a weak safety awareness among employees; this habitual violation of safety rules leads to accidents. Precautionary measures: 1. Strictly implement the two-ticket and three-system management system. 2. Conduct a thorough inspection of the interlocks in the high-voltage switchgear to ensure that their reliability meets safety requirements. 3. Conduct a thorough inspection of the contactors in the 110KV control cabinet, carry out repairs and replacements, and strictly follow the requirements specified in the protection setting notification forms. 4. Purchase gas masks and high-power emergency lighting. 5. Agreeing to suspend power supply is a serious violation of regulations. 6. Strengthen the company’s safety management and raise the safety awareness of all employees. Accident determination: In accordance with the provisions of the \"Regulations on the Management of Accident and Disruption Determination\", this accident is determined to be a general accident caused by human error. Responsibility determination and assessment: This accident was a minor accident caused by human error. In accordance with the provisions of the \"Rules for Determining Accidents and Disruptions\", the responsibilities of those involved in this accident are as follows: Primary responsible party: xx – 100.00; Secondary responsible parties: xx – 60.00 each; Person in charge of the implementing unit: xx – 30.00. In accordance with the 2012 notice on wage structure adjustments, the penalties are as follows: in the event of a minor accident, the shift team and the responsible team have their safety bonuses fully deducted; other teams on duty have half of their monthly safety bonuses deducted, while the workshop where the accident occurred has one-third of its safety bonus deducted ； Assess and award the full safety bonus to the person responsible for safety management, xxx. In 2012, the amount allocated for assessing company management systems was relatively low, and the fines imposed on those responsible were not significant. Now, a zero has been added to the original value.