Distribution transformer

A pole mounted transformer is a transformer on a pylon. Because of its weight of transformers pole transformers are used in Germany only in the field of medium voltage networks with voltages up to 30 kV. They usually are used to supply a regional, small-scale low-voltage network from the medium-voltage network. As mast transformers ordinary oil-insulated transformers can be used up to a rated power of 160 kVA. 400 kVA possible - With appropriate mast bearing capacity transformers with a rated capacity of 250 and are - in Germany, however, not common.

In Italy pole transformers are used in high voltage to 60 kV. The arrangement looks like this, that a pole transformer is mounted on the pylon. From the Pylon a field of a medium voltage overhead line runs to a medium-voltage station mast. There is another pole transformer is mounted. This feeds into the low voltage network.

If the transformer is mounted in a weather-proof enclosure and a cast-resin may be used. In water protection areas, a cast resin or filled with non- water-hazardous liquid such as synthetic ester transformer must be used.

Normally, mast stations are used to supply outside of towns and remote lying customers, eg farms. But also residential areas with, for example, 50 houses, so larger hamlets, fattening stations with electrical energy from the medium-voltage network are often supplied. When pole transformers of emigrants courts can be used on the low voltage side of the zigzag connection, which means a lower load unbalance in unbalanced loads.

Another application is the supply of electrical equipment from the catenary AC-driven pathways (eg switch heaters, train preheating, ...). In this case, single-phase pole transformers are used.

There are also pole transformers without overhead line feeders. They are a result of a wiring of the incoming and outgoing lines.

Final separation pole with transformer, but without the overhead line

Pole station, concrete pole

Pole transformers in North America

Pole transformer without free cable outlets ( ground wire ) at Magstadt