Isolating Transformer

An isolation transformer is a transformer with a protective separation between the input and output windings. Isolating transformers for general applications, single-phase up to 25kVA and multi-phase up to 40kVA, are usually designed according to EN61558-2-4. If agreed between customer and supplier, this standard can also be applied to isolating transformers without limitation of the output power.

In contrast to the mains transformer (according to EN61558-2-1), the isolating transformer has so-called “double or reinforced” insulation in addition to the basic insulation. (Some types may also have a combination of the basic insulation with a shield winding between the input and output winding in its place).

Note:
A “transformer with separate windings” (ugs.) is a mains transformer and has basic insulation.

See also: Mains transformer