Transformer help

Hello guys

I have a 3-phase, 250kVa transformer at my site.

Specs on its label are:

250kVa
cooling type: ONAN
freq: 50hz
rated voltage: 20.000/400

My question is:

How many 1phase , 220v , 3500 watt cryptocurrency servers can i run simultaneously without damaging the transformer ?

In on other words, how many amps can each phase withstand , by approaching the limit but without damaging the transformer ?