Dry type transformer operating temperature range

-20°C is the normal minimum operating range of transformers. At temperatures below, when a transformer is first energized, “bad” things can happen as it warms up. Once energized, -40°C isn’t a problem for the transformer. The normal limitation is the temperature rating of the cable being connected to the transformer. It is usually not rated for -40°C, which will cause the insulation to crack and eventually fail.

For a selection of Eaton's dry type transformers please see our Catalog Volume 2 Tab 2.