The Australian Mac 128k machines had 110v power supplies and shipped with an external 240v => 110v step down transformer. However, nearly every 128k that I encountered had at some stage been connected directly to 240v and had its original power/sweep board "blown up".

I suspect that this machine has had its original power/sweep board replaced with a 240v one at some stage during its life.

From what I understand, the convertible / 240v Power/Sweep boards were even LESS reliable than the 110v ones used elsewhere.