Neutral to earth linking on distribution switchboards installed prior to January 2003 may remain. Removal of the earth link is to prevent neutral currents flowing in the sub-main earth conductor.
Note: If it is proposed to remove an existing neutral to earth link in a distribution switchboard, a detailed examination of the sub-main earthing system is required BEFORE the link is removed, to ensure the correct operation of protective devices after the link removal. See the current AS/NZS 3000 Section 5 for the minimum size of protective earth conductors.
