I wake this old thread. As far as I know Germany was pretty standardized to 220/380V Y 3-phase even before WWii.

An the other hand local standards has been surviving surprisingly many years.

Here in Norway we still have 230V 3-phase with no neutral. 3 wires with 230 V between and measured about 127 to ground until the first failure. Sometimes this results in a grounded phase and 230V between ground and the 2 others. On these systems we use 2 fuses, or more recent dual circuit breakers.
Where we have 230/400V (newer) with a grounded center of the Y we still use double breakers, but not fuses. You shall not be able to switch off neutral without switching off live wires. This mix of systems makes the color-code of neutral wire confusing, because we use the same rolls of cables. Where Neutral is, it shall be blue, but when you have no neutral blue might be live wire. Actually no problem, always treat a wire as live!

Some of the very first 230V systems with neutral had fuses, but not on neutral. They even tried to use common neutral and ground to the receptacle, this is not by code anymore.

dsk