What is the pour point of transformer oil and why is it important for low temperatures?

The pour point is the lowest temperature at which transformer oil can still flow. It is critical for cold climates because oil must circulate through radiators and cooling ducts during startup and winter operation. If the pour point is too high, oil circulation is impaired, leading to overheating and accelerated insulation aging. Low pour point oils ensure reliable cooling and protection at subzero ambient temperatures.