Australian safety requirements 2003

The Dept of Energy Safety inspected my 'shed' on Nov 21, 2003.  My equipment runs from 50 V AC to make it pass the Western Australian requirements.  Higher voltages require a qualified electrician unless they are 'downstream' of the 50 V AC. This is provided by an arc welder stepping down the 240 V AC mains to 50 V AC (120 A peak).  The 50 V AC is then stepped up (by another arc welder wired in reverse) to