Such a retrofit, if done properly, could lead to a significant increase in rated power, from 10 to 40%. To provide an exact number is very difficult since the result depends on many factors, like the average ambient temperature around the transformer, the number, power and position of the fans, and many other factors. It would be best to purchase a transformer with forced cooling integrated initially. Please contact your local ABB service representative to see what can be the best approach for adding additional cooling.
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