Ambient temperature and power reduction

The ambient temperature is the highest temperature that a transformer is able to be used for the long-term. Unless otherwise agreed, the transformers are designed for a maximum ambient temperature of 40 °C.

The transformers must be installed so that the necessary cooling is guaranteed. This must be taken into account, especially in enclosures with a high degree of protection. Transformers with cooling ducts must be installed in such a way that the ducts are positioned vertically. Deviating from 40 °C ambient temperature, the rated power according to the following table must be reduced for higher temperatures.
Ambient temperature45°C50°C55°C60°C
Reduced power95 %85%80%75%