Medium-voltage coil MV

LVepoxy resinwith round section wire

Overview

Resin-impregnated windings for power transformers, normally cylindrical. On request they can be manufactured in rectangular form, typically used for LV/LV windings in special applications. Windings can be produced to customer specifications and may include custom marking or logos on request.

Construction and variants

• Cylindrical or rectangular geometry.
• Designed for medium- and low-voltage applications.
• Custom dimensions and configurations available on request.

MV winding technologies

• Wire-type construction
• Strip/foil-type construction

Partial-discharge tests

Partial-discharge measurements have been carried out on numerous coils in accordance with IEC 726, consistently registering values below 10 pico-coulomb (pC). This level of partial discharge is guaranteed provided the transformer assembly respects the required dimensional and procedural parameters, in particular the distance between HV and LV coils and distances to earth.

Impulse test

Multiple transformers assembled with our coils have successfully passed impulse tests according to IEC 76-1-5. The same assembly and dimensional conditions required for partial-discharge performance apply to impulse testing.

Thermal-shock test (IEC 726)

The thermal-shock test consists of cooling the coil to -25°C over 8 hours, maintaining that temperature for a further 12 hours, then energizing the coil with a current equal to twice the rated value to reach an over-temperature of 110°C without causing cracks.