G Kenyon
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New Zealand
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Date:  28 February 2026
Lancashire.
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Author:  Graham Kenyon
FY5 2LX.
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G Kenyon
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Amendment Record
Rev Date
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Change Record
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Purpose
03
28/02/2026
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Graham Kenyon
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02
25/02/2025
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Second draft
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01
16/02/2026
Draft for Review
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Graham Kenyon

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Executive Summary
This report documents a review by an independent expert of the technical decision taken to list
the deletion of Clauses 2.3.2.1.2(b) and (c) from AS/NZS 3000:2018 (including Amendments 1, 2
and 3) in Schedule 2 to the New Zealand Electricity (Safety) Amendment Regulations 2025. The
report concludes that the decision is justified, but that there are residual risks. Some of the
residual risks are already mitigated by existing practices, standards and guidance, whilst others
require additional industry guidance and/or standards to be implemented.

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Figures & Tables
Figure 2.1 Example of path of possible diverted neutral currents ............................................ 15
Figure E.1 Figure 8 from IEC 60669-1:2017 ............................................................................ 34

Table 2.1 Potential risks associated with the removal of Clauses 2.3.2.1.2 (b) and (c) from
AS/NZS 3000:2018 ............................................................................................................... 17
Table 3.1 Potential mitigation already in place of risks associated with the removal of Clauses
2.3.2.1.2 (b) and (c) from AS/NZS 3000:2018 ......................................................................... 19

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1  Introduction
1.1  Formal details
1.1.1  This report has been prepared by Graham Harry Kenyon, Managing Director and Principal
Consultant of G Kenyon Technology Ltd, 15, Westmorland Ave, Thornton-Cleveleys,
Lancashire, FY5 2LX, United Kingdom.
1.1.2  I am a Chartered Engineer,  Member of the Institution of Engineering and Technology, a
registered  European Engineer through Engineers Europe (formerly FEANI),  and a
Technical Member of the Institute of Occupational Safety and Health. My career history
and experience exceeds 30 years. I practise as an independent international electrical
engineering consultant with relevant experience in electrical installations, and electrical
1987
product assurance and safety. I have been in my current position for 10 years 10 months,
previous to which my experience was engineering and technical assurance, for projects
developing and implementing specialist systems for major infrastructure programmes. I
Act
have been actively involved with standardization in the electrotechnical sector for around
20  years, and have held formal qualifications in UK electrical installation design,
installation and verification practice since 1992. I am the current Chair of joint IET/BSI
Committee JPEL/64, which is the UK national committee responsible for a number of
standards including BS 7671 Requirements for Electrical Installations (IET Wiring
Regulations, 18th Edition), and the international IEC 60364 series, and also the current
Chair of UK technical committee GEL/600 responsible for BS 7430 Code of Practice for
Earthing. I am the author of an extensive range of electrotechnical industry guidance and
training publications  for the  UK;  a comprehensive list can be found at:
Information
https://www.gkenyontech.com/the-principal/publications/.
1.1.3  I have been engaged by WorkSafe New Zealand to conduct a technical review, which is
outlined in the background to this report (Section 1.2).

Official
1.2  Background
1.2.1  Schedule 2 to the  New Zealand  Electricity  (Safety)  Amendment Regulations 2025
the
[reference 1]  deletes Clauses 2.3.2.1.2(b) and (c) from AS/NZS 3000:2018 (including
Amendments 1, 2 and 3) [reference 2].
1.2.2  The provisions of Clauses 2.3.2.1.2(b) and (c) from AS/NZS 3000:2018 (including
Amendments 1, 2 and 3) [reference 2]  relate to conditions for switching neutral
conductors in electrical installations, and prohibition of switching of protective earthing
under
conductors and combined protective earth and neutral (PEN) conductors.  Specific
provisions of these Clauses are examined in Section 2 of this Report.
1.2.3  The intent of deleting Clauses 2.3.2.1.2(b) and (c) from AS/NZS 3000:2018 (including
Amendments 1, 2 and 3) [reference 2] for New Zealand was to ‘future proof’ the New
Zealand  Electricity (Safety) Amendment  Regulations  2925 [reference 1], to facilitate:

(a)  Improvements in the integrity of electricity supplies to homes as a result of power
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outages in the distribution network, by permitting switching arrangements to ‘island’
the installation to operate from a source of energy independent from the public
distribution network  (for example, temporary generators or renewable energy
systems with battery storage); and

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(b)  Permit the future use of protective devices that can operate to disconnect electric
vehicles from all live conductors, and the protective earthing system, in the event of
detection of conditions indicative of a broken PEN conductor upstream of the supply
to the electric vehicle charging equipment. The Institution of Engineering and
Technology (IET) in the UK published a standard for such devices,  IET 01:2024
[reference 3].
1.2.4  WorkSafe New Zealand have received correspondence from the New Zealand Electrical
Inspectors Association, which has been reviewed by myself after I formed an
independent opinion.
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2  Risks associated with removal of Clauses 2.3.2.1.2 (b) and (c) from
AS/NZS 3000:2018
2.1  Clauses 2.3.2.1.2 of AS/NZS 3000:2018 [reference 2]
2.1.1  Clause 2.3.2.1.2 of AS/NZS 3000:2018 [reference 2] is as follows (highlights are made for
clarity in later Paragraphs of this review report):
2.3.2.1.2 Alternating current systems
Provisions for isolation of conductors in a.c. systems are as follows:
(a)  Active conductors All active conductors of an a.c. circuit shall be capable of being isolated by a
1987
device for isolation.

(b)  Neutral conductor:
(i)  No switch or circuit-breaker shall be inserted in the neutral conductor—
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(A)  of consumer mains; or
(B)  where the neutral conductor is used as a combined protective earthing and neutral
(PEN) conductor for protective earthing of any portion of an electrical installation.
NOTE: This requirement applies to situations such as an earth sheath return (ESR) system
or a submain neutral used for earthing of an electrical installation in an outbuilding in
accordance with Clause 5.5.3.1.
(ii)  A switch or circuit-breaker may operate in the neutral conductor of circuits other than those
in Item (i) where—
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(A)  the neutral pole of a multi-pole switch or circuit-breaker, having an appropriate short-
circuit breaking and making capacity, is linked and arranged to switch substantially
together with all active poles; or
(B)  the switch or circuit-breaker is linked with corresponding switches so that the neutral
contact cannot remain open when the active contacts are closed.
A switched neutral pole shall not open before and shall not close after the active pole(s).
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(iii) Where an item of switchgear is required to disconnect all live conductors of a circuit, it shall
be of a type such that the neutral conductor cannot be disconnected or reconnected without
the respective active conductors also being disconnected or reconnected.
the
NOTE: The manual disconnection and connection of neutral conductors should be as
follows:
(a)  The active conductors should be disconnected before the neutral conductors.
(b)  The neutral conductors should be connected before the active conductors.
under
Refer to AS/NZS 4836 for safe work practices.
(iv) A switch in the control circuit of a fire pump shall operate in the neutral conductor in
accordance with Clause 7.2.5.6.4.
In accordance with Clause 2.5.1.1, no fuse shall be inserted in a neutral conductor.

(c)  Switching of earthing conductor prohibited An earthing conductor shall not be isolated or
switched.
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A conductor used as a combined protective earthing and neutral (PEN) conductor shall not be
isolated or switched.

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2.1.2  Clause 2.3.2.1.2 (b) of AS/NZS 3000:2018 [reference 2], highlighted with a blue outline in
Paragraph 2.1.1 of this report,  divided into four sub-clauses, numbered  2.3.2.1.2 (b)(i),
2.3.2.1.2 (b)(ii), 2.3.2.1.2 (b)(ii ) and 2.3.2.1.2 (b)(iv).  The sub-clauses  deal with
prohibitions on, or switching of, neutral conductors, including PEN conductors, and are
analysed in subsequent Sections of this report as follows:
(a)  Section 2.2 summarizes facts regarding the reasons for deletion of 2.3.2.1.2 (b) and
(c) of AS/NZS 3000:2018 [reference 2].
(b)  Section  2.3  summarizes  facts  regarding  risks associated with switching a PEN
conductor that 2.3.2.1.2 (b) (i) and the second paragraph of 2.3.2.1.2 (c) intend to
prevent.
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(c)  Section 2.4 summarizes facts regarding the risks associated with switching a neutral
conductor other than a PEN conductor, without opening the line (active) conductors,
that 2.3.2.1.2 (b) (ii) and (i i) intend to prevent.
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2.1.3  Clause 2.3.2.1.2 (c) of AS/NZS 3000:2018 [reference 2], highlighted with a green outline
in Paragraph 2.1.1 of this report, prohibits switching of an earthing conductor (protective
conductor in IEC 60364 series and BS 7671)  including a PEN conductor. These are
analysed in subsequent Sections of this report as follows:
(a)  Section  2.3  summarizes facts regarding risks associated with switching a PEN
conductor that 2.3.2.1.2 (b) (i) and the second paragraph of 2.3.2.1.2 (c) intend to
prevent.
(b)  Section  2.5  summarizes facts regarding the risks associated with switching of an
Information
earthing conductor that  2.3.2.1.2 (c) of AS/NZS 3000:2018 [reference 2] intends to
prevent.
2.1.4  The deletion of Clause 2.3.2.1.2 (b)(iv) of AS/NZS 3000:2018 [reference 2] was, on review,
considered inconsequential, as it simply makes reference to two other Clauses, 7.2.5.6.4
and 2.5.1.1, neither of which are deleted by the Electricity (Safety) Amendment
Official
Regulations 2025 [reference 1].

the
2.2  Reasons for deletion of 2.3.2.1.2 (b) and (c) of AS/NZS 3000:2018
[reference 2]
2.2.1  Standards are currently in development for switching arrangements for operation of
electrical installations in New Zealand in island mode. Guidance exists for carrying out
under
the operation manually at present (see Paragraph 2.2.6 of this report).
2.2.2  Island mode is the mode of operation of an electrical installation in which is
disconnected from the grid, and supplied from a local energy supply, for example a rotary
generator, or inverters supplied by batteries, wind, and/or solar PV.
2.2.3  For safety of those operating on a public supply network, it is known that operation of an
installation in island mode  will involve disconnection of live (active and neutral)
conductors within the installation from the grid.
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2.2.4  A complicating factor is the multiple earthed neutral (MEN) arrangements can be
extended to other parts of an installation such as an outbuilding.  There are two key
aspects that might affect the use of MEN arrangements within an installation  with
renewable energy systems in island mode:
(a)  Due to low fault currents associated with renewable technology inverters, RCDs are
often necessary, and these are not compatible with PEN conductors.
(b)  It is generally considered dangerous practice to recombine neutral and protective
(earthing) functions once they are separated. This is prohibited in BS 7671.
2.2.5  It is not known at this stage precisely how island mode switching arrangements will be
achieved in standards and guidance in New Zealand, especially given the complicating
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factors outlined in Paragraph 2.2.4 of this report.
2.2.6  However,  standards and guidance are already in place for the manual temporary
Act
connection of a generator by licensed electrical workers, see:
(a)  WorkSafe New Zealand Technical Bulletin Connecting a generator to the wiring of a
house or building following an emergency [reference 4];
(b)  AS/NZS 4509 .1 Stand-alone power systems part 1: Safety and installation
[reference 5].
2.2.7  Consideration was also given to the possible future use of protective devices that can
operate to disconnect electric vehicles from all live conductors, and the protective
earthing system, in the event of detection of conditions indicative of a broken PEN
Information
conductor upstream of the supply to the electric vehicle charging equipment. The
Institution of Engineering and Technology (IET) in the UK published a standard for such
devices, IET 01:2024 [reference 3], termed ‘open PEN detection devices’ (OPDDs).
2.2.8  During a fault resulting from a broken PEN conductor, touch-voltages on conductive
parts of electric vehicles connected to  a charging point can, under certain
circumstances, exceed the line-to-Earth voltage if the break in the PEN conductor is in a
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three-phase portion of the distribution system. OPDDs remove the danger by
disconnecting all live (active and neutral) conductors, and, at the same time, the
protective (earthing) conductor to the charging point, which would otherwise continue to
the
transfer  the  raised PEN conductor potential to conductive parts of the vehicle.  This
necessarily requires switching of the earthing conductor.

2.3  Risks associated with
under switching a PEN conductor
2.3.1  Sub-clause  2.3.2.1.2 (b)(i) of AS/NZS 3000:2018 [reference 2]  prohibits switching of a
neutral conductor of the consumer mains, or a PEN conductor.
2.3.2  The effect of switching a PEN conductor is to remove both protective earthing and neutral
functions  from exposed-conductive-parts downstream of the switch.  The risks
associated with switching a PEN conductor depend on whether the circuit (or service)
associated with the PEN conductor is single-phase or three-phase, and whether multiple
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earthing (MEN) provisions are available downstream of the disconnected PEN conductor.
2.3.3  It is not desirable to switch a PEN conductor under any circumstances. Not all countries
permit switching of protective conductors in their national wiring codes. The UK is one
country that does, but even in the UK, switching of PEN conductors is not permitted (see
Appendix C Section C4 of this report).
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2.3.4  If a PEN conductor is switched at the same time as the other live conductors:
(a)  The earthing resistances on an MEN distribution network as a whole are changed.
(b)  Touch-voltages  can  develop  between exposed-conductive-parts, and earthing
(protective) conductors, on both sides of the switched conductor.
2.3.5  If a PEN conductor is switched and line (active) conductors are not also disconnected,
the resulting impact depends on the following factors:
(a)  whether the circuit or system is single-phase or three-phase; and
(b)  if the PEN conductor is part of an MEN system, or there is bonding or fortuitous
contact with the Earth either directly or indirectly through extraneous-conductive-
1987
parts, so that there is a PEN return path around the switched PEN conductor due to
low effective earth electrode resistance.
2.3.6  In single-phase circuits and systems with PEN conductors, exposed-conductive-part
Act  s
downstream of an open-circuit PEN conductor can have a touch-voltage of up to the line-
to-Earth voltage with respect to the general mass of Earth. This risk can be reduced inside
buildings where main protective bonding is in place.
2.3.7  In three-phase circuits and systems with PEN conductors, the PEN conductor
downstream of the open-circuit PEN conductor is a neutral, and will assume a voltage
dependent on the balance of loads connected  downstream of the open-circuit PEN
conductor, which appears as a touch-voltage with respect to the general mass of the
Earth at exposed-conductive-parts and, if applicable, bonded extraneous-conductive-
Information
parts downstream of the open-circuit PEN conductor.  The  touch-voltage, in some
conditions, can  exceed the line-to-Earth voltage with respect to the general mass of
Earth, and in rare conditions could approach the line-to-line voltage.
2.3.8  The touch-voltages described in Paragraphs 2.3.6 and 2.3.7 of this report can be reduced,
to an extent, by:
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(a)  Provision of earth electrodes with very  low  values  earth electrode resistances,
connected to the PEN conductor downstream of the disconnection. The values of
earth electrode resistance that reduces the possible touch-voltages to a level that
the
might be considered generally safe in dry conditions depends on the connected load.
Based on calculations carried out for electric vehicle charging installations supplied
by protective multiple earthing (PME) systems in the UK, the values of earth electrode
resistance are generally  only  considered  practicable  in cases where there is
extensive metallic contact with the ground (for example, buildings with a piled steel-
under
framed buildings. The calculated resistances are:
(i)
In single-phase systems, values of earth electrode resistance of less than 1 Ω
would be needed to maintain touch-voltages below 70 V AC for supplies up to
100 A.
(ii)
In three-phase systems  the touch-voltage developed depends on phase
unbalance. Similar values of earth electrode resistance would be required to
Released  maintain touch-voltages below 70 V AC for supplies up to 100 A, unless phase
unbalance can be guaranteed to be better than 100 %, 60 %, 37 %.
(b)  Inside buildings, by provision of main protective bonding, although note that
conductive parts connected to the protective bonding, that are accessible outdoors,
will then be subject to a potentially dangerous touch-voltage.
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2.3.9  In the case of a dangerous touch-voltage described in Paragraphs 2.3.6 and 2.3.7 of this
report, neither overcurrent protective devices nor residual current devices (RCDs) will
operate to provide automatic disconnection of the touch-voltage.

2.4  Risks associated with switching a neutral conductor other than a PEN
conductor
2.4.1  Sub-clauses 2.3.2.1.2 (b)(ii), 2.3.2.1.2 (b)(i i) and 2.3.2.1.2 (b)(iv) of AS/NZS 3000:2018
[reference 2] relate to conditions that must be satisfied for switching a neutral conductor
(other than a PEN conductor). These can be summarized as follows:
1987
(a)  The neutral is not to be switched without also switching the associated active (line)
conductors.
(b)  When switching all live (active and neutral) conductors, the switching is to b
Act  e
arranged so that either:
(i)
all live (active and neutral) poles are linked so that all live contacts make and
break at substantially the same time; or
(ii)
all live (active and neutral) poles are linked so that the neutral contact does
not open before the active (line) contact(s), and the neutral contact does not
close after the active (line) contact(s).
2.4.2  In single-phase systems and circuits,  disconnecting  a neutral conductor  without
Information
switching the associated line conductors generally disconnects power from loads;
however, all live conductors downstream of the disconnected neutral conductor remain
live. This could post a shock risk to anyone maintaining the installation, including removal
of lamps at general lighting service points.
2.4.3  In three-phase systems and circuits, disconnecting a neutral without also disconnecting
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the active (line) conductors means that the neutral is ‘floating’ and will assume a voltage,
relative in the phasor world to the live conductors, based on the balance of the loads
downstream of the disconnected neutral. In this case, the voltage between any line and
the
neutral could attain a voltage of up to the line-to-line voltage, or in rare cases with non-
unity power factor, exceed the line-to-line voltage.
2.4.4  Undervoltage is often experienced by equipment  in general; however,  due to the
magnitude of overvoltage experienced by single-phase equipment connected between a
line and neutral downstream of the switched neutral, serious overvoltage can be
under
experienced. Overvoltage from broken neutrals in three-phase systems has been known
to not only damage equipment, but also lead to fire. The situation in a real open neutral
situation  is often exacerbated by the fact that, as modern  equipment  with internal
electronic and control circuitry becomes inoperative or is damaged by overvoltage, the
balance of loads is continually shifting.
2.4.5  Where the timing arrangements summarized in Paragraph 2.4.1(b) of this report are not
met, the neutral can be disconnected when the live conductors are connected. This can
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lead to the risks described in Paragraphs 2.4.2 to 2.4.4 inclusive of this report; however,
in this case, the risk of fire resulting is generally less because of the short time involved.
Damage to equipment, however, can still result, particularly if a three-phase circuit is
being switched.

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2.5  Risks associated with switching an earthing conductor (protective
conductor) other than a PEN conductor
2.5.1  Clause 2.3.2.1.2 (c) of AS/NZS 3000 [reference 2]  effectively prohibits switching or
disconnection of the earthing (protective) conductor. Risks associated with switching of
a PEN conductor are summarized in Section 2.3 of this report.
2.5.2  Switching earthing (protective) conductors without switching live conductors is generally
considered dangerous as it removes the protective provision of automatic disconnection
of supply, in a manner that, if a fault were to occur, exposed-conductive-parts would
remain hazardous live.
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2.5.3  In many installations, protective conductor currents result from electromagnetic
compatibility filters, and if the protective conductor is open-circuit, such currents can
flow to Earth through someone in contact with exposed-conductive-parts. If the
Act
protective conductor is interrupted to a number of items of equipment, or a number of
circuits, that remain live, the sum of protective conductor currents can, on their own, be
lethal with no electrical fault, unless the protective conductor remains continuous.
2.5.4  There is concern regarding switching of protective conductors (other than through the
removal and reinsertion of a multi-pole plug and socket-outlet), that if a switching device
has a protective conductor contact, this can, over time, fail. A user may be unaware of
the damage, leading to permanent disconnection of the earthing (protective) conductor.
Such risks can be alleviated by only permitting switching of the protective conductor by
dedicated equipment to an appropriate product standard that includes durability tests,
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and/or where there is monitoring of the earthing system  through the protective
conductor.

2.6  Risks associated with the use of PEN conductors and remote system
referencing connections in electrical instal
Official ations operating in island
mode
2.6.1  In system with TN-C or TN-C-S earthing arrangements, diverted neutral current is a term
the
used to describe neutral current, that would normally flow back to the source of energy
via the PEN conductor, but instead are diverted through other low resistance paths,
including:
(a)  fortuitous connection of protective (earthing) conductors, including PEN conductors,
under
with the ground, or conductive parts in contact with the ground;
(b)  bonded extraneous-conductive-parts that form an effective low resistance earth
electrode (for example metallic non-electrical service pipework, or the steel frame of
a building);
(c)  exceptionally low resistance earth electrodes (for example where the steel frame of
a building is used as an earth electrode).
2.6.2  The proportion of diverted neutral current depends on the earth electrode resistances,
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soil resistivity, and presence of conductive material in the ground. It is not something that
is easy to predict without extensive investigation for a given site.
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2.6.3  If the PEN conductor of the MEN network remains connected to an electrical installation
operating in island mode, diverted neutral currents from PEN conductors in the
installation can return to the island mode source via the MEN network as a parallel path,
as illustrated in Figure 2.1. This can provide a risk to persons working on the MEN system,
even where the MEN system is de-energized for the work to be carried out.
2.6.4  Whilst the proportion of diverted neutral current in many cases is likely to be small with
respect to load current, currents of only a few milliamperes can be fatal.
2.6.5  If the diverted neutral current results from shared metalwork (for example, metallic
service pipes) between two separate electrical installations, however, a large proportion
of diverted neutral current can be expected.
1987

Figure 2.1 Example of path of possible diverted neutral currents
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Distribution
Electrical
network
installation
Island mode
power source
Disconnected
in island mode
+ ‒
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Main building
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the
Load current
Outbuilding
Diverted neutral current
load
under
Outbuilding

NOTE:  see Paragraph 2.6.10 of this report regarding the earthing arrangement for connecting
the island mode power source.
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2.6.6  ‘System referencing’ is a term that is recently appearing  in  IEC standards,  see
IEC 60364-1 [reference 21], to mean the connection of a live part or conductor to Earth
for the purpose of forming a suitable earthing arrangement associated with protection
against electric shock. The system referencing conductor is the conductor that connects
the live part to an earthing conductor to enable the live part to be substantially at the
potential of the earthing arrangement.
2.6.7  The location of the system referencing conductor is important to the operation of certain
protective devices.
2.6.8  In installations where small-scale embedded generators are used to provide power to the
installation in island mode, the available fault currents can be insufficient to operate
1987
overcurrent protective devices, and residual current devices  (RCDs) are necessary to
provide protection against electric shock.
2.6.9  If the system referencing conductor is not provided immediately after the grid-forming
Act
embedded generator, the generator connecting circuit might not be effectively protected
against electric shock by automatic disconnection of supply, as an RCD in that circuit will
not operate for a fault in the embedded generator circuit.
2.6.10  The arrangement shown in Figure 2.1 shows how a system referencing point effectively
includes ‘combining’ of neutral and protective conductors from the perspective of the
island mode source  of supply.  This is prohibited in IEC 60364-5-54:2011+AMD1:2021
(see Paragraph D6-1 in Appendix D of this report). It is not clear how such a conflicting
requirement  might  be interpreted in multi-source, or switchable-source,  systems.
Ideally, a PEN conductor should be used to connect the island mode source to the
Information
switchboard.
2.7  Existing guidance for connecting temporary generators
2.7.1  The existing guidance for connecting temporary or stand-alone generators [references 4
and  5]  address the risks outlined in Paragraphs 2.6.1  to  2.6.5, by temporarily
Official
disconnecting the MEN connection to the installation.
2.7.2  The existing guidance for connecting temporary or stand-alone generators [references 4
and  5]  do not consider the fact that the MEN is to be disconnected. If this is not
the
appropriately insulated, or there are exposed-conductive parts connected to the
islanded installation that are simultaneously-accessible with exposed-conductive-parts
connected to  the MEN system  outside the installation, then dangerous potential
differences can be experienced.
under

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2.8  Summary of potential risks associated with the removal of Clauses
2.3.2.1.2 (b) and (c) from AS/NZS 3000:2018
2.8.1  See Table 2.1.
Table 2.1 Potential risks associated with the removal of Clauses 2.3.2.1.2 (b) and (c) from
AS/NZS 3000:2018
Ref  Removal of
Potential
Cause
For hazard
provision in
hazard
detail, see
AS/NZS 3000
Paragraph
1
2.3.2.1.2 (b)(i)
Possible electric
•  Hazardous touch-voltages between  2.3.2, 2.3.3,  1987
and
shock or
simultaneously-accessible
2.3.6, 2.3.7,
2.3.2.1.2 (c)
secondary
exposed-conductive-parts
2.3.8, 2.3.9,
effects
connected to different earthing
2.7.2
systems (IEC 60364-4-41,
Act
Clause 411.3.1.1)
2
2.3.2.1.2 (b)(i)
Possible electric
•  Change of earthing resistances in
2.3.4, 2.7.2
and
shock or
‘global earthing’ system.
2.3.2.1.2 (c)
secondary
•  Hazardous touch-voltages between
effects.
simultaneously accessible
exposed-conductive-parts
connected to different earthing
systems (IEC 60364-4-41,
Clause 411.3.1.1)
3
2.3.2.1.2 (b)(i)
Possible electric
•  Diverted neutral currents from
2.6.1 to 2.6.5
Information

shock or
islanded installation to distributor
inclusive.
NOTE: also,
secondary
MEN if this is not switched (and PEN
lack of
effects.
conductors are permitted in
guidance for
islanded installations)
islanded
installations.
Official
4
2.3.2.1.2 (b)
Possible electric
•  Failure to disconnect live
2.4.2, 2.4.3,
shock or
conductors on operation of devices
2.4.5
secondary
that ought to provide safe
the
effects during
disconnection/isolation
maintenance
5
2.3.2.1.2 (b)(i ),  Possible damage  •  Disconnected neutral in a three-
2.4.4, 2.4.5
2.3.2.1.2 (b)(i i)  to equipment
phase system or circuit when active
and 2.3.2.1.2
(line) conductors remain
(b)(iv)
connected.
under
6
2.3.2.1.2 (b)(i ),  Possible
•  Disconnected neutral in a three-
2.4.4, 2.4.5
2.3.2.1.2 (b)(i i)  fire/burns
phase system or circuit when active
and 2.3.2.1.2
(line) conductors remain
(b)(iv)
connected.
7
2.3.2.1.2 (c)
Possible electric
•  Disconnected protective conductor  2.5.2
shock or
and high protective conductor
secondary
currents.
effects.
Released
8
2.3.2.1.2 (c)
Possible electric
•  Disconnected protective conductor  2.5.3, 2.5.4
shock or
and electrical fault that would
secondary
normally conclude with automatic
effects.
disconnection of supply.

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Review of technical decision for WorkSafe New Zealand
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3  Existing mitigation in place for the risks outlined in Section 2 of this
report
3.1  During my investigation, there was evidence that specific risks summarized in Section 2
of this report are mitigated, at least in part, by other provisions already in place.
3.2  The mitigation and recommended residual risk actions are summarized in Table 3.1.

1987
Act
Information
Official
the
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Table 3.1 Potential mitigation already in place of risks associated with the removal of Clauses 2.3.2.1.2 (b) and (c) from AS/NZS 3000:2018
1987
Ref  Removal of
Potential
Cause
For hazard
Mitigations already  Recommended residual risk actions
provision in
hazard
detail, see
in place
AS/NZS 3000
Paragraph
Act
1
2.3.2.1.2 (b)(i)  Possible electric
•  Hazardous touch-
2.3.2, 2.3.3,  Installing this type
A.  Switching of PEN conductors appears to be
and
shock or
voltages between
2.3.6, 2.3.7,  of switching is highly
permissible. Guidance or standards are
2.3.2.1.2 (c)
secondary
simultaneously-
2.3.8, 2.3.9,  likely to involve
necessary to prevent switching of PEN
effects
accessible exposed-
2.7.2
licensed
conductors.
conductive-parts
workers/inspectors.

connected to different
B.  It is advisable, for the implementation of island
earthing systems (IEC
mode switching, to prohibit MEN/PEN
60364-4-41, Clause
conductors in parts of electrical installations
411.3.1.1).
that are to be islanded. This is necessary to
prevent diverted neutral (PEN) currents from
within an islanded installation being conducted
Information
through the general mass of the Earth.
2
2.3.2.1.2 (b)(i)  Possible electric
•  Change of earthing
2.3.4, 2.7.2
Installing this type
and
shock or
resistances in ‘global
of switching is highly  C.  Standard arrangements for automatic
2.3.2.1.2 (c)
secondary
earthing’ system.
likely to involve
switching of island mode are yet to be
effects.
addressed.
•  Hazardous touch-
licensed

voltages between
workers/inspectors.  D.  In a global market, not all products meet every
Official
simultaneously
country’s national requirements, and without
accessible exposed-
industry guidance, other countries have found
conductive-parts
particular safety issues associated with
the
connected to different
islanding. IEC 63445 [reference 12] could be
earthing systems (IEC
considered for the system referencing
60364-4-41, Clause
conductor switching.
411.3.1.1).
under
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Review of technical decision for WorkSafe New Zealand
  Technology
Ref  Removal of
Potential
Cause
For hazard
Mitigations already  Recommended residual risk actions
provision in
hazard
detail, see
in place
1987
AS/NZS 3000
Paragraph
3
2.3.2.1.2 (b)(i)  Possible electric
•  Diverted neutral
2.6.1 to
Manual

shock or
currents from islanded
2.6.5
disconnection of
Act
NOTE: also,
secondary
installation to
inclusive.
MEN conductor in
lack of
effects to those
distributor MEN if this is
existing guidance
E.  Consider prohibition on the use of PEN
guidance for
working on the
not switched (and PEN
(see Section 2.7 of
conductors in islanded installations. See also
islanded
MEN distribution
conductors are
this report)
risk reduction action B.
installations.  system.
permitted in islanded
installations)
4
2.3.2.1.2 (b)
Possible electric
•  Failure to disconnect
2.4.2, 2.4.3,  Installing this type
shock or
live conductors on
2.4.5
of switching is highly
secondary
operation of devices
likely to involve
effects during
that ought to provide
licensed
maintenance
Information
safe
workers/inspectors.
disconnection/isolation

5
2.3.2.1.2
Possible damage  •  Disconnected neutral
2.4.4, 2.4.5
Product standards,
(b)(ii),
to equipment
in a three-phase
such as IEC 60947
F.  Standards or guidance for other products, and
2.3.2.1.2
system or circuit when
series, IEC 60947-6-
installation arrangements, to replace the
(b)(iii) and
active (line) conductors
1 and IEC 60669
provision of AS/NZS 3000 Clause 2.3.2.1.2
2.3.2.1.2
remain connected.
series, contain
(b)(ii) and (iii) is necessary.
Official
(b)(iv)
requirements that
6
2.3.2.1.2
Possible
•
2.4.4, 2.4.5
mimic AS/NZS 3000
  Disconnected neutral
(b)(ii),
fire/burns
in a three-phase
Clause 2.3.2.1.2
the
2.3.2.1.2
system or circuit when
(b)(ii) and (iii). See
(b)(iii) and
active (line) conductors
Appendix E to this
2.3.2.1.2
remain connected.
report.
(b)(iv)
under
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Technology
Ref  Removal of
Potential
Cause
For hazard
Mitigations already  Recommended residual risk actions
provision in
hazard
detail, see
in place
1987
AS/NZS 3000
Paragraph
7
2.3.2.1.2 (c)
Possible electric
•  Disconnected
2.5.2
Installing this type
shock or
protective conductor
of switching is highly
Act
secondary
and high protective
likely to involve
G.  Consider reinstating 2.3.2.1.2 (c), or
effects.
conductor currents.
licensed
implementing necessary requirements similar
workers/inspectors.
to BS 7671 (see Appendix C, C6). This will

permit the use of OPDDs as well as transfer
For non-automatic
switching that also transfers the protective
arrangements,
(earthing) function between sources of supply.
AS/NZS 4509.1

applies.
H.  Consider mandating standards for open-PEN
detection devices (OPDDs), for example IET
8
2.3.2.1.2 (c)
Possible electric
•  Disconnected
2.5.3, 2.5.4
Installing this type
01:2024 [reference 3], that contain provisions
shock or
protective conductor
of switching is highly
for durability. It is noted that automatic transfer
secondary
and electrical fault that
likely to involve
Information
switching is covered by IEC 60947-6-1
effects.
would normally
licensed
[reference 8], which is already listed in the
conclude with
workers/inspectors.
legislation. IEC 63445 [reference 12] could also
automatic

be considered.
disconnection of
supply.
Official
the
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Review of technical decision for WorkSafe New Zealand
  Technology
4  Conclusion
4.1  This Section of the Report provides a conclusion summarizing the opinion of the expert
who conducted the review.
4.2  Changes to the Electricity (Safety) Regulations were necessary to safely implement
renewable technologies and consider provisions for supply continuity under certain
circumstances. Specifically, and with reference to Paragraph 1.2.3 of this report, it should
be noted that:
(a)  Switching of protective (earthing) and neutral conductors is necessary to permit
supply changeover/transfer; and to permit protection by OPDDs.
(b)  Switching of PEN conductors  would not, in ideal circumstances, be considered;
1987
however, unless the use of PEN conductors in installations is to be restricted, there
are risks to persons working on the MEN distribution system.
Act
4.3  The deletion of Clauses 2.3.2.1.2(b) and (c) from AS/NZS 3000:2018 (including
Amendments 1, 2 and 3) [reference 2] for New Zealand  intended  to achieve the aim
outlined in Paragraph 1.2.3 of this report.
4.4  Table 3.1 outlines specific residual risks that result from the decision (see Paragraph 4.3
of this report), some of which are mitigated as identified in the table.
4.5  The residual risks identified in Table 3.1 can be summarised as follows:
(a)  Switching of PEN conductors should be prohibited  under all circumstances  and
applied in conjunction with item 4.5(b). The reintroduction of 2.3.2.1.2 (b)(i) should
Information
either be considered or addressed in subsequent guidance. (Residual risk action A in
Table 3.1.)
(b)  It is recommended that the use of PEN conductors in parts of installations energized
in island mode is prohibited. (Residual risk actions B and E in Table 3.1.)
(c)  Standards or guidance for manual or automatic island mode switching arrangements
should be provided. (Residual risk actions B, C, D and E in Table 3.1.)
Official
(d)  Not all product standards include timing arrangements for switching neutral
conductors in conjunction with other live conductors. The reintroduction of 2.3.2.1.2
the
(b)(ii), 2.3.2.1.2 (b)(ii ) should be considered, or addressed in subsequent guidance
and/or product standards.  IEC 63445 [reference 12]  could be considered for the
system referencing conductor switching. (Residual risk actions D and F in Table 3.1.)
(e)  Provisions should be put in place in standards or guidance, and relevant product
standards mandated where appropriate, to cover situations in which it is necessary
under
to switch an earthing (protective earth) conductor. (Residual risk actions D, G and H
in Table 3.1.)
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Technology
4.6  To  address the  residual risks associated with  switching the PEN conductor  outlined in
4.5(a), reinstating a prohibition on switching this protective conductor is recommended.
This in turn would introduce a risk associated with islanding installations that themselves
contain PEN conductors that are intended to remain energized in island mode.  This is
addressed in this report by recommending a prohibition on the use of PEN conductors in
parts of installations energized in island mode, see Paragraph 4.6(b) of this report.
4.7  With respect to the correspondence received from the New Zealand Electrical Inspectors
Association discussed in Paragraph 1.2.4, I have reviewed the correspondence following
for formation of an initial opinion, and, in my view, the hazards raised in that
correspondence have been described in Section 2 of this report, and any residual risks
1987
outlined in Section 3 of this report.
4.8  The review concluded that, on balance, the decision to deletion of Clauses 2.3.2.1.2(b) and
(c) from AS/NZS 3000:2018 (including Amendments 1, 2 and 3) [reference 2] for New
Act
Zealand is technically justifiable, when the following is taken into account:
(a)  In terms of the switching of PEN conductors, see Paragraph 4.5 item (a), there is a
residual risk with existing installations operating in island mode, regardless of
whether the decision is taken to either:
(i)
permit switching of PEN conductors with the aim of protecting those working
on an MEN distribution network (see Paragraphs 2.6.1 to 2.6.5 inclusive of this
report), or
(ii)
to prohibit  disconnection of the PEN conductor of the distribution system
Information
whilst PEN conductors in the installation remain energized (see Paragraphs
2.3.1 to 2.3.9 inclusive, Paragraphs 2.6.6 to 2.6.10 inclusive, and Section 2.7,
of this report).
(b)  Guidance and standards are being developed to address the residual risks outlined
in Paragraph 4.5 items (b) to (e) inclusive of this report.
Official
(c)  The application of guidance and standards yet to be developed might be limited if
Clauses 2.3.2.1.2(b) and (c) from AS/NZS 3000:2018 (including Amendments 1, 2 and
3) [reference 2] were to be retained in their present form.
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Appendix A  References and related documents
No.  Reference*
1.  New Zealand Electricity (Safety) Amendment Regulations 2025, last accessed
18 February 2026 from:
https://www.legislation.govt.nz/regulation/public/2025/0225/latest/whole.html
2.  AS/NZS 3000:2018 (including Amendments 1, 2 and 3) Electrical installations “Wiring
Rules”
3.  Institution of Engineering and Technology Standard IET 01:2024 Open combined
protective and neutral (PEN) conductor detection devices (OPDDs) (IET, London,
ISBN 978-1-83953-885-8)
4.  WorkSafe New Zealand Technical Bulletin Connecting a generator to the wiring of a  1987
house or building following an emergency, last accessed 18 February 2026 from:
https://www.worksafe.govt.nz/dmsdocument/57543-technical-bulletin-connecting-a-
generator-to-the-wiring-of-a-house-or-building-following-an-emergency/latest/  Act
5.  AS/NZS 4509.1:2009 stand-alone power systems part 1: Safety and installation
6.  BS 7671:2018+A2:2022+ A3:2024 Requirements for Electrical Installations. IET Wiring
Regulations Eighteenth Edition
7.  IEC 60947-6-1:2005+AMD1:2013 Low-voltage switchgear and controlgear – Part 6-1:
Multiple functional equipment – Transfer switching equipment
8.  IEC 60947-6-1:2021 Low-voltage switchgear and controlgear – Part 6-1: Multiple
functional equipment – Transfer switching equipment
9.  IEC 60947-1:2007+AMD1:2000+AMD2:2014 Low-voltage switchgear and controlgear –
Part 1: General rules
Information
10. IEC 60947-1:2020 Low-voltage switchgear and controlgear – Part 1: General rules
11. IEC 60669-1:2017 Switches for household and similar fixed-electrical installations -
Part 1: General requirements
12. IEC 63445:2025 System referencing conductor switching device (SRCSD)
13. IEC 60364-5-53:2015 (HD 60364-5-57:2017) Electrical installations of buildings –
Part 5-53: Selection and erection of electrical equipment – Isolation, switching and
Official
control
14. Institution of Electrical Engineers General Rules Recommended for Wiring of the
Supply of Electrical Energy, Fourth Edition, 1903
the
15. Institution of Electrical Engineers Wiring Rules, Seventh Edition 1916
16. Institution of Electrical Engineers Regulations for the Electrical Equipment of
Buildings, Fourteenth Edition 1966
17.  linked switch. (n.d.) McGraw-Hill Dictionary of Architecture and Construction. (2003).
under
Retrieved 17 February 2026 from
https://encyclopedia2.thefreedictionary.com/linked+switch
18. BIPM The International System of Units (SI) 9th Edition 2019 (updated to 2024)
19. NIST Special Publication 811 Guide to the International System of Units (SI)
20. NIST Technical Note 1297 Guidelines for Evaluating and Expressing the Uncertainty of
NIST Measurement Results 1994 Edition
21. IEC 60364-1:2025 Ed 6.0 Low-voltage electrical installations - Part 1: Fundamental
principles, assessment of general characteristics, and definitions
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* References which are without a date or revision / version are intended to refer the reader to the latest revision / version.
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Appendix B  Abbreviations and specialist terms
Abbreviations for SI Units, SI Derived Units, and related Non-SI Units are not listed here due to
their widespread use and standard application. Details of these units can be found in
references 18 and 19.
Term
Meaning
AC
Alternating current
Note:  ‘a.c.’ is used in AS/NZS 3000, and in older IEC, CENELEC and British
standards. In the text of this Report, ‘AC’ is used, following current IEC usage,
unless quoting such standards directly.
AS/NZS
Australian Standard/New Zealand Standard (National Standards jointly published by 1987
Standards Australia and Standards New Zealand)
BIPM
Bureau International des Poids et Mesures
(International Bureau of Weights and Measures)
BS
British Standard (UK National Standards)
Act
DC
Direct current
Note:  ‘d.c.’ is used in AS/NZS 3000, and in older IEC, CENELEC and British
standards. In the text of this Report, ‘DC’ is used, following current IEC usage,
unless quoting such standards directly.
EN
Euro-Norm (European Union Regional Standard Standard)
IEC
International Electrotechnical Commission
IET
Institution of Engineering and Technology (formerly the IEE)
IEE
Institution of Electrical Engineers
Island mode
Operating mode of an electrical installation in which it is disconnected from the public
distribution network, temporarily or permanently, and loads within the installation are
Information
supplied by one or more local sources of energy.
NOTE:  sometimes, the term ‘grid independent’ is used for an electrical installation
that is permanently disconnected from the public distribution network.
MEN
Multiple earthed neutral
ISO
International Organisation for Standardisation
NIST
National Institute of Standards and Technology (United States of America)
Official
PEN
Protective earth and neutral (combined)
SI
Système Internationale (International System of Units)
SRCSD
System referencing conductor switching device
the
System
A conductor between a live part and an earthing arrangement, enabling the live part to
referencing
be substantially at the same potential as the earthing arrangement. The system
conductor
referencing conductor is neither a neutral conductor nor a protective conductor.
See IEC 60364-1:2025 [reference 21] Clause 1.8.4.
UK
United Kingdom
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Appendix C  Provisions for and prohibitions on switching protective, neutral
and PEN conductors in BS 7671
C1  General
C1-1  The current national electrical installation standard in the United Kingdom is
BS 7671:2018+A2:2022+A3:2024 [reference 6].
C2  Supply transfer arrangements
C2-1  The selection of switching and earthing arrangements for supply changeover, whether
automatic or manual, is specifically covered by Regulation 537.1.5 of BS 7671
[reference 6] which has the following provisions:
1987
537.1.5 Where an installation is supplied from more than one source of energy, one of which requires
a means of earthing independent of the means of earthing of other sources and it is necessary to
provide that not more than one means of earthing is applied at any time, a switching device may be
Act
inserted in the connection between the neutral point and the means of earthing, provided that the
device is:
(i) a multipole, linked switching device arranged to disconnect and connect the earthing conductor
for the appropriate source at substantially the same time as the related live conductors, or
(ii) a switching device interlocked with a multipole, linked switching device inserted in the related
live conductors such that the earthing conductor for the appropriate source shall not be interrupted
before the related live conductors and shall be re-established not later than when the live conductors
are reconnected.
Information
Switching devices provided in accordance with (i) and (ii) shall meet the requirements of Chapter 46
for a device for isolation.
C3  Switching of the neutral conductor
C3-1  Regulation 132.14.2 is a general requirement of BS 7671 [reference 6] and contains the
provision that only linked switches or circuit-breakers, either of which also breaks the line
Official
conductors, may be used in the neutral conductor:
132.14.2 No switch or circuit-breaker, except where linked, or fuse, shall be inserted in an earthed
neutral conductor. Any linked switch or linked circuit-breaker inserted in an earthed neutral conductor
the
shall be arranged to break all the related line conductors.
C4  Prohibition on switching a PEN conductor
C4-1  BS 7671  [reference 6]  does not permit switching of a PEN conductor, see Regulation
411.4.3:  under
411.4.3 In a fixed installation, a single conductor may serve both as a protective conductor and as a
neutral conductor (PEN conductor) provided that the requirements of Regulation 543.4 are satisfied.
No switching or isolating device shall be inserted in the PEN conductor.
NOTE:  Regulation 8(4) of the Electricity Safety, Quality and Continuity Regulations prohibits the
use of PEN conductors in consumers’ installations.
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C5  Prohibition on forming a PEN conductor from separate neutral and protective
conductors
C5-1  BS 7671 [reference 6] does not permit the recombining of separate neutral and protective
conductors to re-establish a PEN conductor, see Regulation 543.4.3:
543.4.3 If, from any point of the installation, the neutral and protective functions are provided by
separate conductors, those conductors shall not then be reconnected together beyond that point. At
the point of separation, separate terminals or bars shall be provided for the protective and neutral
conductors. The PEN conductor shall be connected to the terminals or bar intended for the protective
earthing conductor and the neutral conductor. The conductance of the terminal link or bar shall be not
less than that specified in Regulation 543.4.5.
1987
C6  Switching of the protective conductor (other than a PEN conductor)
C6-1  Regulation 543.3.3.101 of BS 7671 [reference 6] contains the following provisions:
Act
543.3.3.101 No switching device shall be inserted in a protective conductor, except:
(i) as permitted by Regulation 537.1.5
(ii) a multipole, linked switching device in which the protective conductor circuit is not interrupted
before the live conductors and is re-established not later than when the live conductors are
reconnected
(iii) a switching device interlocked with a multipole, linked switching device inserted in the live
conductors such that the protective conductor circuit shall not be interrupted before the live
conductors and shall be re-established not later than when the live conductors are reconnected, or
Information
(iv) a multipole plug-in device in which the protective conductor circuit shall not be interrupted before
the live conductors and shall be re-established not later than when the live conductors are reconnected.
Switching devices provided in accordance with (i), (ii), (iii) and (iv) shall meet the requirements of
Chapter 46 and Section 537 for a device for isolation.
Official
Joints for test purposes that can be disconnected only by the use of a tool may be inserted in a
protective conductor.
C6-2  Switching of a protective conductor (including an earthing conductor) is by a single-pole
the
switching device inserted in the conductor, interlocked with a multipole linked switch
that operates to disconnect live conductors, is therefore clearly permitted by BS 7671
[reference 6], using the options in:
(a)  indent (i) to Regulation 534.3.3.101, via the option in indent (ii) to Regulation 537.1.3;
under
or
(b)  indent (iii) to Regulation 534.3.3.101.
C7  Meaning of the term ‘linked switch’ in BS 7671
C7-1  The term linked switch has been used in BS 7671, and the predecessor UK industry
standard commonly known as the ‘IEE Wiring Regulations’, published by the Institution
of Electrical Engineers (IEE) for a period exceeding 120 years. A definition for the term first
appeared in Regulation 100 of the Fourth Edition of the IEE Wiring Regulations
Released
[reference 14] which was published in 1903:
100. Linked switches.– Linked switches are single-pole switches fixed on conductors of different
polarity linked together mechanically so as to operate simultaneously.
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C7-2  The definition cited in Paragraph C7-1 of this Appendix remained in use in subsequent
Editions of the IEE Wiring Regulations, from the Fourth to the Sixth, until the Seventh
Edition [reference 15] was published in 1916, which contained the following definition
introducing a ‘definite sequence’ of operation:
Switch, linked. A switch the blades of which are so linked mechanically as to make or break all poles
simultaneously or in a definite sequence.
The definition remained unchanged until the Fourteenth Edition [reference 16] published
in 1966 (see Paragraph C7-3 of this Appendix).
C7-3  The current definition in Part 2 of BS 7671:2018+A2:2022+A3:2024 [reference 6] is:  1987
Switch, linked. A switch the contacts of which are so arranged as to make or break all poles
simultaneously or in a definite sequence.
This definition has not changed since the Fourteenth Edition of the IEE Wiring
Act
Regulations, first published in 1966 [reference 16].
C7-4  There is no definitive statement in the current edition of BS 7671 [reference 6] that the
poles of a ‘linked switch’ are required to be mechanically linked; however the following
ought to be considered:
(a)  It is generally considered in the industry that the term ‘linked switch’ refers to a
multipole switch in which the linkages are mechanical in nature. For example, the
McGraw-Hill Dictionary of Architecture and Construction [reference 17] defines the
Information
term ‘linked switch’ as:
Two or more electric switches which are mechanically connected by operating arms or levers, so as
to operate at the same time or in a desired sequence;
and
(b)  BS 7671 [reference 6] uses the term ‘interlocked’ in relation to electrical linking in
Official
indent (ii) of Regulation 537.1.5, and indent (iii) of Regulation 543.3.3.101;
and
the
(c)  BS 7671 [reference 6] implements the technical intent of the HD 60364 series
published by CENELEC, as listed in the Preface. The facts regarding the technical
intent in respect of multipole switching devices being required be mechanically
linked are presented in Appendix D, D7 of this report.
under
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Appendix D  Provisions for and prohibitions on switching protective, neutral
and PEN conductors in IEC 60364 series
D1  General
D1-1  Relationship with AS/NZS 3000
D1-1-1  The preface to AS/NZS 3000:2018 [reference 2] states that one of the objectives of
the revision from AS/NZS 3000:2007 was to ‘maintain alignment with IEC 60364, Low
voltage electrical installations (series)’.
D1-2  Relationship with BS 7671
D1-2-1  BS 7671:2018+A2:2022+ A3:2024 [reference 6] implements the technical intent of 1987
CENELEC harmonized documents (HDs) as shown in the Preface to the standard.
HD 60364 series implements IEC 60364 series in CENELEC.
Act
D2  Supply transfer arrangements
D2-1  IEC 60364 series appears to leave supply transfer switching to IEC 60947-6-1. It is not
clear what conditions pertain when switching between supplies that have different, and
separate, earthing arrangements.
D2-2  IEC 60364-1:2025 defines a ‘system referencing conductor’ to enable earthing of a live
conductor to be established, preventing the need to switch a protective conductor, see
Clause 1.8.4:
1.8.4 System-referencing-conductors
Information
A system-referencing-conductor (SRC) is a conductor between a live part and an earthing
arrangement, enabling the live part to be substantially at the potential of the earthing arrangement.
The SRC is neither a neutral conductor nor a protective conductor.
NOTE The application of SRC, shown in Figure 9, Figure 10, Figure 11, Figure 12 and Figure 13, is
given to help define the characteristic behaviour of the electric systems.
Official
D3  Switching of the neutral conductor
D3-1  Clause  530.3.2  of IEC 60364-5-53:2015  prohibits switching of the neutral conductor
unless the associated line (active) conductors are also switched:
the
530.3.2  Except as provided in 536.2.2.7, in multiphase circuits, single-pole devices shall not be
inserted in the neutral conductor.
In single-phase circuits single-pole devices shall not be inserted in the neutral conductor, unless a
residual current device complying with the rules of 413.1 of IEC 60364-4-41 is provided on the supply
under
side.
D4  Prohibition on switching a PEN conductor
D4-1  IEC 60364-4-41:2005+A1:2017 does not permit the switching of a PEN conductor, see
Clause 411.4.3:
411.4.3 In fixed installations, a single conductor may serve both as a protective conductor and as a
neutral conductor (PEN conductor) provided that the requirements of 543.4 of IEC 60364-5-54 are
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satisfied. No switching or isolating device shall be inserted in the PEN conductor.
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D5  Switching of the protective conductor (other than a PEN conductor)
D5-1  IEC 60364-5-54:2011+AMD1:2021 does not permit the switching of a protective
conductor, see Clause 543.3.3.
NOTE:  Some countries, including the United Kingdom, permit switching of the
protective conductor under specified conditions.
543.3.3 No switching device shall be inserted in the protective conductor, but joints which can be
disconnected for test purposes by use of a tool may be provided.
D5-2  Similarly, IEC 60364-1, Clause 1.8.3, prohibits switching protective conductors:
1.8.3 Protective conductors
1987
1.8.3.1 General
Protective conductors are those conductors used for protective purposes. Protective conductors
Act
are classified into:
– protective earthing conductors;
– protective bonding conductors.
In a protective conductor the electrical continuity shall be maintained. Accordingly, no switching
device shall be inserted.
D5-3  A distinction that needs to be raised in respect of Paragraph D5-2 of this Appendix, is that
Information
switching of a protective conductor need not occur, if the connection of a live conductor
of the installation to Earth is not classified as a protective conductor, and a the term
system referencing conductor is defined. See Section D2 of this Appendix.
D6  Prohibition on forming a PEN conductor from separate neutral and protective
conductors
Official
D6-1  IEC 60364-5-54:2011+AMD1:2021 does not permit the does not permit the recombining
of separate neutral and protective conductors to re-establish a PEN conductor, see
Clause 543.4.3:
the
543.4.3 If, from any point of the installation, the neutral/mid-point/line and protective functions are
provided by separate conductors, it is not permitted to connect the neutral/mid-point/line conductor
to any other earthed part of the installation. However, it  is permitted to form more than one
neutral/mid-point/line conductor and more than one protective conductor from the PEN, PEL or PEM
conductor respectively.
under
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D7  Requirements for linked switching in IEC 60364-5-53:2015
D7-1  Section 530.3 contains the following provisions:
530.3 General and common requirements
This part of IEC 60364 shall provide compliance with the measures of protection for safety, the
requirements for proper functioning for intended use of the installation, and the requirements
appropriate to the external influences foreseen. Every item of equipment shall be selected and erected
so as to allow compliance with the rules stated in the following clauses of this part and the relevant
rules in other parts of this standard.
The requirements of this part are supplementary to the common rules given in IEC 60364-5-51.  1987
530.3.1 The moving contacts of all poles of multipole devices shall be so coupled mechanically that
they make and break substantially together, except that contacts solely intended for the neutral may
close before and open after the other contacts.
Act
530.3.2  Except as provided in 536.2.2.7, in multiphase circuits, single-pole devices shall not be
inserted in the neutral conductor.
In single-phase circuits single-pole devices shall not be inserted in the neutral conductor, unless a
residual current device complying with the rules of 413.1 of IEC 60364-4-41 is provided on the supply
side.
530.3.3 Devices embodying more than one function shall comply with all the requirements of this
part appropriate to each separate function.
Information
Official
the
under
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Appendix E  Provisions for switching the neutral conductor in relevant
product standards referenced in Schedule 4 to the New Zealand
Electrical Safety (Amendment) Regulations 2025
E1  IEC 60947-1
E1-1  Clause 8.1.9 of IEC 60947-1:2020 [reference 10] has the following provisions in respect
of the neutral pole:
8.1.9 Additional requirements for equipment provided with a neutral pole
When an equipment is provided with a pole intended only for connecting the neutral conductor, this
1987
pole shall be clearly identified to that effect by the letter "N" (see 8.1.8.4).
A switched neutral pole shall break not before and shall make not after the other poles. Act
If a pole having an appropriate short-circuit breaking and making capacity (see 3.7.14 and 3.7.15) is
used as a neutral pole, then all poles, including the neutral pole, may operate substantially together.
The neutral pole may be fitted with an overcurrent release.
For equipment having a value of conventional thermal current (free air or enclosed, see 5.3.2.1 and
5.3.2.2) not exceeding 63 A, this value shall be identical for all poles.
For higher conventional thermal current values, the neutral pole may have a value of conventional
thermal current different from that of the other poles, but not less than half that value or 63 A,
whichever is the higher.
Information

E2  IEC 60947-6-1
E2-1  IEC 60947-6-1:2021 [reference 8] includes a clear, normative, requirement for the live
conductor poles (lines and neutral) of multipole transfer switches to be mechanically
coupled so they operate substantially at the same time. The same Clause also makes
Official
reference to IEC 60947-1:2020 Clause 8.1.9 in respect of the neutral pole (see Paragraph
E1-1 of this Appendix).  the
8.1.5 Opening and closing of main contacts
The main moving contacts of all phase poles of the switching device of a multipole TSE shall be so
mechanically coupled that they make and break substantially together, whether operated manually,
remotely, or automatically.
under
The manual actuator of the TSE shall be insulated. The requirements of 8.1.5.1 of IEC 60947-1:2020
applies.
There shall be no path or opening which allows incandescent particles to be discharged from the area
of the manual operating means.
For TSE equipped with neutral poles, 8.1.9 of IEC 60947-1:2020 applies.
For any TSE with manual operating means intended for on-load use, opening and closing of the main
contacts shall be independent of the speed with which the manual operating means is operated.
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If the manual means is intended only for off-load use with all sources de-energized and is so marked
according to Table 2 item 1.3, this requirement does not apply.

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E3  IEC 60669-1
E3-1  IEC 60669-1:2017  [reference 11]  Clause  14.4  contains provisions for the timing of
switching of the neutral contact in three-pole plus switched neutral switches conforming
to the standard. (See Paragraph E3-2 of this Appendix regarding classification of switches
in terms of pattern numbers according to Clause 7.1 of the standard.)
14.4 Making and breaking
Switches of patter numbers 2, 3,  04 and 6/2 shall make and break all poles substantially
simultaneously except that for switches of pattern number 03, the neutral shall not make after or break
before the other poles.
1987
Compliance is checked by inspection and by manual test when the switch is mounted with the cover,
cover plates and actuating members installed as for normal use.

Act
E3-2  Switches to IEC 60669-1 are classified according to their pattern number as per
Clause 7.1 of the standard (Figure 8 of the standard is reproduced in Figure E.1 on page 34
of this report):
7 Classification
Switches are classified
7.1 according to the possible connections (see Figure 8) Information

Pattern number
—  single-pole switches  . . . . . . . . . . . . . . . .... . . . . . . . . . . . . . . ... . . . . . . . .
1
—  double-pole switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
—  three-pole switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
Official
—  three-pole plus switched neutral switches  . . . . . . . . . . . . . . . . . . . . . . . . .
03
—  two-way switches  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6
—  two-circuit switches with a common incoming line . . . . . . . . . . . . . . . . . .
5
the
—  two-way switches with one off-position . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
—  two-way double-pole switches  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6/2
—  two-way reversing switches (or intermediate switches) . . . . . . . . . . . . . . .
7
under
NOTE 1 Two or more switches having the same or different pattern numbers can be mounted on a common base.
NOTE 2 For the pattern number for which an off-position is considered, the above classification refers also to
push-button switches and momentary contact switches.
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Figure E.1 Figure 8 from IEC 60669-1:2017
1987
Act
Information
Official
the
under

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