https://www.openstreetmap.org/#map=18/37.33725/126.94952
It’s been a while since I saved the substation layer, but the substation is not added to the map.
I erased it and tried it again, but it did not show.
Language: Korean.
Use Google Chrome
Korea Railroad Corporation(KORAIL) Electric Railway Substation
You mean probably this object:
https://www.openstreetmap.org/way/582090802
Standard style doesn’t render specific electric devices and I guess this transformer is just a part of power=substation, which should be rendered if you will tag it.
I suspect that the way plotted is actually the sub-station, not the transformer, as transformers would not, normally, be L shaped.
The wiki also says that transformers should only be mapped as nodes, although I would disagree with that, as, if should be possible to get enough information to plot them as areas, as well. If doing so, I would use an explicit area tag, as some tools might not assume area, given that the wiki doesn’t allow one.
The other thing to remember is that the map is not the standard bit mapped, tiled, image, or any of the many alternatives; it is the data, and the fact that https://www.openstreetmap.org/way/582090802 returns a result means that the feature HAS been added to the map.
There are many different renderings that stress different features. I believe one person maintains one for power distribution features, and, if you are interested in railways, you might find http://product.itoworld.com/map/15 useful.