Great link, thank you.
Why IT? When I asked som 30 years ago, they claimed it to be safer. We should modernize a system from 1940 (IT) and the supplier would change the transformer at the same time, we offered to pay the extra cost to change to 400V TN-S or TN-C-S
but they refused "of safety reasons".
Blessed are the meek,
For they shall inherit the earth. !
