I,m not sure if it is TNC-S or TNS.
Everything are new, the transformer and everything after.
(Yes I'm more into old phones, now I have my fully mechanical 1946 exchange hooked up to internet, and the telephone network.)
Does the transformer step 11kv to 400Y/230? Are all the breakers RCD? Or just some? Or RCD main breaker (huvudbrytare)?
I think that is really cool, nice interest! Very good, I have an interest in old things too. Anything with a cord really.