Oddly. Going from 3ph to 1ph

Customer has a samilpower 12000tl-pm that is currently connected to a three phase supply. For metering reasons he wants to switch to single phase. Is this possible without screwing the inverter? Label on side says 230/400v. Is it intelligent enough to know or does it need programming? My intention on the supply incoming busbar chamber is just to link all three phases together on a single phase. No other 3 phase equipment in use.