Normally yes with step-down transformers that is the case. But with step up transformers you can wire them in reverse. You take a normal transformer step-down 3000VAC:110VAC transformer and feed it's secondary with the 110VAC and you then get 3000VAC on the primary to feed into whatever 3000VAC device. If it's DC they require then it has to go into some sort of AC/DC inverter.