Large distribution transformers are used for receiving energy from higher voltage levels and to transform and distribute this energy to lower voltage substations or directly to large industrial consumers.
Transformers in this range are three-phase and can be manufactured with off-circuit tap changer or on-load tap changer. Transformers provided with on-load tap changer usually have a separate tap winding.
The core is constructed of grain-oriented steel laminations. The windings are made of either copper or aluminum conductor and wound in a foil or multi-layer configuration. The tank construction can be a corrugated fin wall type or of a rigid construction type with radiators typically used for larger transformer. Fans can also be mounted on the radiators to provide additional cooling capacity.
- Primary voltage: up to 36 kV
- Available fluids: mineral oil, dimethyl silicone, esters and synthetic hydrocarbons