@RODALCO
for D:
1,5 mm² is minimum for 3 wire 1 phase
2,5 mm² minimum only for 5 wire 3 phase (mandatory only for range/cooker/oven in kitchen)
> 95 % of actual domestic MCBs are B16, the rest is for direct water heaters B25, B32 (4 or 6 mm² typically)
even B10 is rather rare (more expensive than B16)
N is never switched <-> NL+F, nor protected (B), although allowed.
Situation in Austria is more reasonable. But that's Rangers' topic.
In front of switch panel and counter you will find an E characteristic selective circuit breaker now. Used to be Neozed so far. Mains service is usually fused by NH 63A or more.
Grid is TN-C-S or TT depending on local line provider (VersorgungsNetzBetreiber)
