comments:
theotherharper posted on r/askelectricians1w
You probably mean 400V and 230V, because EU got a voltage bump to that decades ago. It depends on whether neutral is present at that receptacle. If it is, there should be no trouble getting more than one phase of 230V. In America we regularly have this, where a user has an electric dryer 14-30 dryer outlet (2 phases, neutral, ground) but has a methane dryer and needs two 120V outlets (each 1 phase, neutral, ground). They make simple breakout boxes which provide that from that. You just want the CEE 7/5 version of that thing.