In every PREMO transformer, both the high and low voltage windings are produced on modern, state-of-the-art automatic winding machines.
Plates or paper insulated electrolyte copper or aluminum are used as conductive materials in the low voltage windings of distribution transformers. Enamel insulated round or paper insulated flat conductors made of copper or aluminum are used as conductor material in the high voltage windings.

Paper-insulated flat or CTC copper conductors are used in the windings of the power transformers. The windings are designed as twisted and layered windings depending on the design.