|transformer = main|
|A power transformer that forwards power between different voltage grids inside a substation.|
|Used on these elements|
|Tools for this tag|
Main transformers are forwarding power between different parts of a substation.
That kind of transformer are found in substations only.
Most of their capacity is dedicated to power forwarding between different voltages, opposite of auxiliary which feed local substations or premises only.
|Germany||Large outdoor main power transformer in a transmission power substation|
|This transformer has 3 windings operating at 3 different voltages. 225kV side is on the foreground while 63kV is hidden at the back
|This plate can be seen on transformer themselves (picture taken with power grid operator acknowledgement) and gives the windings configuration with several other figures. All tags can be defined with it.
|France||Such transformer are used in France to feed legacy 15kV distribution zones from current 20kV infrastructures.
|France||High speed rail lines are fed from transmission power grid with such biphase transformers.|
On one of each transformer inside of the substation
|Due to pretty long distances, high speed rail 25kV contact lines have to be regularly fed by auto-transformers which take power from a -25kV feeder line going along railways.|
|A simple substation (see POSTE meaning substation in French) can contain a single transformer with a very few equipment. This can be mapped in OSM as a node and then use substation=* and transformer=main simultaneously.|