Siemens has completed an investigation of the reported event.The root cause was determined to be a workmanship error.Based on the information provided by the service engineer, the circuit breaker for the cooling cabinet tripped on site.After trouble shooting, the cse didn't find any abnormalities and turned the breaker on directly without powering off the main first.According to the required technical documentation, the correct operation is as follows: power off the main line in main box first; turn on the circuit breaker in e-box and close the cover of the e-box; power on the main line in main-box.Additionally, the label with electrical warning information on the cover panel of the e-box is marked with "disconnect power before servicing unit." therefore, the reported incident was the result of a workmanship error.
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