@Tes yeux noirs,
Current drawn by the operating phase...
That would presumably be the induction motor you plan to use
is greater than design conditions for the winding
...which I'd guess means one-third of 25 kva
You may not discover single-phasing
,...may not learn you've overloaded the supply winding
until the winding is damaged
...probably when it burns out. Of course it should first get hot but don't depend on that
Under some conditions, you may not recognize it at all.
...., that is, if it doesn't give you a warning of some sort such as its heating
Preventing trouble is simple: use overload protectors in all three phases.
To myself at first this wasn't simple but that's because Tes is doubtless much smarter than me; until I realized that this protection could be fuses
Tes you hafta forgive me