Question 479Electricity & Electronics - Assistant Engineer

The correct answer is A) Check the transformer ventilation fans for proper operation. The reasoning behind this is that a slowly rising transformer core temperature is likely due to an issue with the transformer's cooling system, such as a failure of the ventilation fans. Checking the fans should be the first action to determine if the cooling system is functioning properly and address the root cause of the temperature rise. Reducing the load or notifying the bridge to slow down (options B and D) may be necessary if the cooling issue cannot be resolved, but should not be the initial response. Sending the oiler to look for fires (option C) is incorrect, as a slowly rising temperature does not necessarily indicate a fire hazard and could potentially divert attention from the actual issue with the cooling system.