What is the process for changing the oil in an 11kV transformer?

The process for changing the oil in an 11kV transformer involves several steps. First, ensure the transformer is de-energized and isolated from the power supply. Next, drain the old transformer oil using a pump, ensuring proper containment for disposal. After draining, inspect and clean the internal components. Then, refill the transformer with new, filtered transformer oil, ensuring it meets the required specifications. Finally, perform tests to confirm the integrity and functionality of the transformer before re-energizing.