https://wiki.openstreetmap.org/wiki/Key:substation

substation=distribution:
Substations that mainly relates to regional distribution networks **without any individual subscriber** delivery. It often include sites with regional **or local coverage**

substation=minor_distribution:

A small substation at the **lowest level of transforming** in the distribution grid. This kind of substation **directly supplies households** and small businesses with **low voltage** power.

10к к домам не подходит. Фотография к substation=minor_distribution как бы намекает, что это не подстанция с несколькими трансформаторами на окрытом воздухе, огороженная забором.