AS/NZS 3000:2018 (known as the Wiring Rules) is a comprehensive document, comprising over 600 pages. It is written in two parts: Part 1 provides the scope, application, and fundamental principles (pp 33-74), while Part 2 provides prescriptive guidance in such a way that an installation which meets the requirements of part 2 is deemed to comply with the requirements of Part 1.
However, the standard makes clear that an installation can be engineered to meet the requirements of Part 1 without needing to meet all (or indeed any) of the prescriptive requirements of Part 2 of the standard.
This submission explores examples where solutions which achieve compliance via Part 1 assessment and documentation may be best overall for the asset owner. Plainly such examples are for commercial or industrial situations rather than regular domestic sites, where site-specific matters have sufficient bearing that bespoke solutions are warranted.
Various examples will be explored, including the following:
โข Isolated LV supplies to wayside assets in the rail industry, for which optimal outcomes may be achieved without any buried elements on the โisolatedโ side of the supply
โข Opportunities to provide separation between various elements of a location supplied at LV without the use of an isolating transformer โ including identification of risks/threats to such an installation
โข Examples where โprivateโ LV installations might use a combined PEN conductor in situations which otherwise do not clearly comply with the strict interpretation of all the clauses within Part 2