When the mains power fails or is in an abnormal state such as phase loss, overvoltage, or under voltage, the ATS system automatically starts the standby diesel generator set according to the preset mains loss confirmation delay. After confirming that the output voltage of the generator set is normal, it automatically switches to For the generator set, the load is powered by the generator set; when the mains power returns to normal, it will automatically switch to restore the mains power supply to the load after confirmation by a preset delay. After the generator set is unloaded, it will automatically stop after a preset cooling operation.