|Primary voltage of a power transformer|
|Used on these elements|
|Tools for this tag|
A transformer is a power device and it has got different interfaces that can be documented separately.
See dedicated documentation about those interfaces.
Some configurations may be complex, see windings=* also for more information.
The primary voltage (421-03-06) is the voltage bound to the interface which gets power from the supply source (upside network or generator).
It's a constant design convention we intend to describe here. As of today, power can actually flow in every direction connected to a power transformer depending on power grid operational status OSM isn't aware of and then won't change primary side established during mapping.
How to find the value
generator transformer, in power plants
They are intended to step-up voltage coming from a power generator, the primary voltage is lower than voltage:secondary=* since the power outputs on the high voltage side.
It is understood that in special circumstances, for maintenance operations purpose for instance, power plants can actually consume power from the network through their step-up transformers. It doesn't change the chosen convention for OSM as those transformers are first of all designed to transmit power from generators.