2013/1/26 François Lacombe <francois.laco...@telecom-bretagne.eu>: > According to some previous explanations, power=station and power=sub_station > must be renamed since the sense isn't clear at all.
the sense in OSM is perfectly clear and defined in the osm wiki: power=station describes a substation for high voltage. power=sub_station is a substation for transforming medium to low voltage. This is also defined in the wiki. > If "normal" (what is normal please?) mappers don't know the voltage, they > don't upload data, that's all. why should we create a situation where you will no more be able to map substations if you don't know the voltage? There is really no advantage from excluding mappers. > We can have the information just by looking how the substation is built. Air > insulation distances are highly representative of the voltage. A wiki page > already gives the method : 1m per 100kV. > http://wiki.openstreetmap.org/wiki/Key:voltage fine. You can do this. But it isn't necessary to keep this in mind to map substations. Never had a problem distinguishing power=station from power=sub_station. > Physically : You're right, I see a difference. But it's only due to voltage. > Voltage is requiring air insulation distances which must be respected! Thus, > in a 400 kV substation, design will be very different than the residential > surburbs 380V one. Moreover, power exchanges between the two interfaces of a > power transformer has an influence on the size of that transformer. That's > all. > Functionally : It's the same. The power is switched and transformed the same > way in both places. There's really no difference. maybe you have to accept that OSM tagging is not always following consistent classifications or logics. Please keep in mind that we are not discussing how we could map something that wasn't mapped until now. You are questioning the established system of how things were done in the past years (and which had worked well until now). We (i.e. the community) should decide if the benefits of introducing more consistency are bigger than the hazzle which mappers, editor maintainers and data consumers will have when changing the system. To reduce potential problems I still suggest not to remain under the "power"-key with a potential redesign but INTRODUCE A NEW KEY! > With this in mind, we'd better to tag every substation with power=substation > and put any extra tag to define what kind of substation it is. -1, don't share this idea. IMHO a completely different substation apperance and size, usage etc. are sufficient arguments to keep different main entities (classes) in osm. There is no rule that we have to have strictly functional classification, and in the past mappers had found it useful to have the classes like this. cheers, Martin _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
