Where wiring is fixed near building surfaces, as described in clauses 220.127.116.11 and 18.104.22.168.2 of AS/NZS 3000:2018, one of the protection methods outlined in clause 22.214.171.124 below must be employed.
As in many cases the circuit will be protected by a RCD and the requirements of this clause will be met. However for consumer mains, sub-mains and other non RCD protected circuits, one of the other methods will need to be applied. Option (b) below is probably easier to achieve with the use of earthed rigid or flexible steel conduit. Below is clause H5.4 which provides the requirements to achieve WSX3.