What is the most efficient 3-phase to single-phase AC transformer for a home grid

Question

So a friend of mine is getting electrical power installed for an urban site he bought, and I'm just trying to be a good friend by looking into this. The company doing the installation recommended he go with 3-Phase AC current (230v because this is in the EU) just so that he'd be able to install an all-electric heating unit down the line. Now, it's obvious 3-phase power is incompatible with the vast majority of household electronics, so he's going to need some sort of transformer hooked-up.

This other question I stumbled upon mentions three different types: LeBlanc, Scott-T and Open-Delta.

Are any of these the most efficient? As-in, which gives the best conversion percentage and has the lowest idle power-loss. If not these, is there another you know of?

Thanks you in advance for any valuable insight you can provide.

Answer 1

The 230/400V three phase system used in most of Europe can supply either three-phase 400V loads or single phase 230V loads (or a combination of both) with no transformer or special switchgear required, beyond standard switchgear such as MCBs.

230V single phase loads are connected between neutral and any phase (ideally, they should be divided up roughly equally between all three).

400V three phase loads, with or without neutral, are connected to all three phases, and the neutral if required by the load.

Any electrician worth their salt will be able to do this easily. If they can't, they should have no place anywhere near a three-phase board.