This specific device was serving as stabilizer and protector on a medic lab,
that they do blood exams ( tests ) .
There was on it as load , about four professional blood analyzers ...
The reason that it was removed , was that it did not had an battery backup option.
The specific design with the 220/220 transformer , it does eliminate the (live phase ) issue,
so you have clean AC (no phase ) , plus some active stabilization .
I was hopping that those pictures will ring a bell to some one , as design,
and I could possibly learn more about it, as specs ..
About need ... what can I say ...
1) what it will cost an modern APC 2KVA unit ?
2) Every serious electronics repairs shop , always had an 220/220 transformer as phase isolator ,
the 2 KVA it is an overkill .
3) I will probably keep it for future use , its a monster , it can protect loads of sensitive equipment .
And about my concern of data specs , it uses Thyristors , so the "efficiency factor" it must be related to them ...
We need an True electronics engineer , to evaluate it even from the pictures , and to offer his thoughts about it..