Autotransformer protections

[patm72]

I work for a company where we are designing machines working at 480V comprising a 75HP PMSM motor driven by a VFD and appropriate controls. The service voltage (480V) enters the unit through a MCCB, from which we split between the “Input Reactor – VFD – Sine Filter – Motor” branch and another for control to a small 2 kVA transformer. For a specific project in Canada, we need to introduce an autotransformer inside the unit to step down the voltage from 600V. Consequently, my MCCB now receives 600VAC, feeds the autotransformer which will then feed the aforementioned branches. Should I add protection after the autotransformer prior to the VFD? This is normally protected by my MCCB when working at 480V.