What is a Kva in simple terms, for somebody who doesn't know electrical engineering?
Transformers are rated in kVA which if the load was pure linear resistive heater loads then kVA=kW kilowatts while some converter is going to be also storing some energy called Reactive which adds to the DC load here which is tiny V*I= watts.

Normally Amp breaker ratings may exceed kVA/V=kiloAmps at line V but is chosen for protection of wires but the transformer will be fused for kVA per phase divided by kV voltage to get rated current.