AS NZS 3003 1999 electrical installations

Title

AS/NZS 3003:1999 Electrical installations - Patient treatment areas of hospitals and
medical and dental practices

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AS/NZS 3003:1999

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Australian/New Zealand Standard™
Electrical installations—Patient
treatment areas of hospitals and
medical and dental practices


AS/NZS 3003:1999
This Joint Australian/New Zealand Standard was prepared by Joint Technical
Committee HT/21, Wiring of Medical Treatment Areas in Hospitals. It was

approved on behalf of the Council of Standards Australia on 23 November 1998
and on behalf of the Council of Standards New Zealand on 7 December 1998. It
was published on 5 February 1999.

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The following interests are represented on Committee HT/21:
Association of Consulting Engineers, Australia
Australian Chamber of Commerce and Industry
Australian Dental Association
Australian Federation for Medical and Biological Engineering
Australian Nursing Federation
Australian Private Hospitals Association
Australian Society of Anaesthetists
Biomedical Engineering Advisory Group SA
Canterbury Area Health NZ
College of Biomedical Engineering Institution of Engineers Australia
Department of Public Works and Services NSW
Electricity Supply Association of Australia
Health Department, WA
Institute of Hospital Engineering (Australia)
Medical Industry Association of Australia
Ministry of Commerce, NZ
NSW Health Department
National Electrical Contractors Association of Australia
Royal Australasian College of Physicians
South Australian Health Commission

Review of Standards. To keep abreast of progress in industry, Joint Australian/
New Zealand Standards are subject to periodic review and are kept up to date by the

issue of amendments or new editions as necessary. It is important therefore that
Standards users ensure that they are in possession of the latest edition, and any
amendments thereto.
Full details of all Joint Standards and related publications will be found in the Standards
Australia and Standards New Zealand Catalogue of Publications; this information is
supplemented each month by the magazines ‘The Australian Standard’ and ‘Standards
New Zealand’, which subscribing members receive, and which give details of new
publications, new editions and amendments, and of withdrawn Standards.
Suggestions for improvements to Joint Standards, addressed to the head office of either
Standards Australia or Standards New Zealand, are welcomed. Notification of any
inaccuracy or ambiguity found in a Joint Australian/New Zealand Standard should be
made without delay in order that the matter may be investigated and appropriate action
taken.

This Standard was issued in draft form for comment as DR 94087.


AS/NZS 3003:1999

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Australian/New Zealand Standard™
Electrical installations—Patient
treatment areas of hospitals and
medical and dental practices

First published as part of AS 3003 — 1996.
Second edition 1985.
Jointly revised and redesignated, in part, AS/NZS 3003:1999.

Published jointly by:
Standards Australia
1 The Crescent,
Homebush NSW 2140 Australia
Standards New Zealand
Level 10, Radio New Zealand House,
155 The Terrace,
Wellington 6001 New Zealand
ISBN 0 7337 2479 5


AS/NZS 3003:1999

2

PREFACE
This Standard was prepared by the
Committee HT/21, Wiring of Medical
AS 3003 — 1985. It specifies special
treatment areas of hospitals. These
AS 3000, SAA Wiring Rules.

Joint Standards Australia/Standards New Zealand
Treatment Areas in Hospitals, to supersede, in part,
requirements for electrical installations in patient
requirements are additional to those specified in

This Standard encourages reference to AS/NZS 2500, Guide to the safe use of electricity
in patient care, and particularly the flow chart included therein, to enable the level of
electrical supply protection necessary to be determined by evaluating the type of

procedures to be undertaken in a particular area and the type of equipment used.
Treatment areas in which medical electrical procedures are to be electively undertaken can
then be identified and wired as body-protected electrical areas or cardiac-protected
electrical areas to provide the necessary level of electrical shock protection in the mains
supply wiring and, where appropriate, earthing systems.

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The earliest consultation between hospital management and the electrical design engineers
is recommended, to jointly evaluate the elected procedures likely to be undertaken, in
order to determine which areas of the hospital or medical or dental practice should be
wired as body-protected electrical areas or as cardiac-protected electrical areas.
This Standard is intended to apply only to installations (or alterations or additions thereto)
made or carried out after the date on which the Standard is published. However, it is
strongly recommended that hospital managements carefully evaluate the procedures
undertaken within existing installations, and that they take steps to implement the
appropriate electrical safety requirements specified herein for areas that are used for
cardiac-type procedures or for procedures involving the regular use of medical electrical
equipment.
While the Standard is intended to apply to new installations or extensions, some guidance
is given concerning conversion of older installations.
Changes to the 1985 edition include the following:
(a)

Revision of the definitions of body-protected and cardiac-protected areas.

(b)

Introduction of the term ‘leakage protected circuit’ to describe a circuit protected by
a residual current device or an isolated electrical supply.

(c)

Introduction of the term ‘leakage protective device’ to describe either a residual
current device or an isolated electrical supply.

(d)

Introduction of requirements for earth leakage protection for socket-outlets which
are outside the defined protected electrical areas but which would normally be
expected to be used to power equipment located within the area.

(e)

Removal of the requirements for access to overcurrent protective devices.

(f)

The number of socket-outlets at patient locations no longer mandated.

(g)

Inclusion of requirements for socket-outlets intended for cleaning purposes.

(h)

Removal of requirements for the design, construction and testing of isolated
electrical supplies and their relocation in AS/NZS 4510.

(i)

The revised presentation information on testing and commissioning in a more
logical sequence for the convenience of persons carrying out the tests.

(j)

Alterations to the requirements relating to equipotential earthing systems in
cardiac-protected areas.


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AS/NZS 3003:1999

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The terms ‘normative’ and ‘informative’ have been used in this Standard to define the
application of the appendix to which they apply. A ‘normative’ appendix is an integral
part of a Standard, whereas an ‘informative’ appendix is only for information and
guidance.

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AS/NZS 3003:1999

4

CONTENTS
Page
SECTION 1 SCOPE AND GENERAL
1.1 SCOPE . . . . . . . . . . . . . . . . .
1.2 APPLICATION . . . . . . . . . . .
1.3 REFERENCED DOCUMENTS
1.4 DEFINITIONS . . . . . . . . . . . .
1.5 METHOD OF MARKING . . . .

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SECTION 2 GUIDANCE
2.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2 AREA SELECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.3 CLASSIFICATION SELECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
SECTION 3 BODY-PROTECTED ELECTRICAL AREAS
3.l GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 SUPPLY WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 EARTHING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4 ACCESS TO LEAKAGE PROTECTIVE DEVICES AND
ISOLATION MONITORS . . . . . . . . . . . . . . . . . . . . . .
3.5 SOCKET-OUTLETS . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6 RESIDUAL CURRENT DEVICES (RCDs) . . . . . . . . . .
3.7 LOW VOLTAGE ISOLATED SUPPLIES . . . . . . . . . . .
3.8 ISOLATING SWITCHES . . . . . . . . . . . . . . . . . . . . . .
3.9 MARKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.10 COMMISSIONING . . . . . . . . . . . . . . . . . . . . . . . . . .

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SECTION 4 CARDIAC-PROTECTED ELECTRICAL AREAS
4.l GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 SUPPLY WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 EARTHING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4 ACCESS TO LEAKAGE PROTECTIVE DEVICES AND LINE
ISOLATION MONITORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.5 SOCKET-OUTLETS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.6 RESIDUAL CURRENT DEVICES (RCDs) . . . . . . . . . . . . . . . . . . . . . . .

4.7 ISOLATED SUPPLIES (OTHER THAN ELV) . . . . . . . . . . . . . . . . . . . . .
4.8 ISOLATING SWITCHES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.9 MARKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.10 COMMISSIONING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
APPENDICES
A RATIONALE FOR THE REQUIREMENTS OF THIS STANDARD .
B PLANNING OF AREAS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C MARKING OF BODY-PROTECTED ELECTRICAL AREAS AND
CARDIAC-PROTECTED ELECTRICAL AREAS . . . . . . . . . . . . . .
D COMMISSIONING TESTS FOR BODY-PROTECTED ELECTRICAL
AREAS AND CARDIAC-PROTECTED ELECTRICAL AREAS . . . .

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. . . . . . 33
. . . . . . 38
. . . . . . 42
. . . . . . 43


5

AS/NZS 3003:1999

Page
E
F
G
H

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I
J

MEASURES FOR AVOIDING INTERFERENCE FROM MAGNETIC FIELDS
METHOD FOR MEASURING MAGNETIC FIELDS . . . . . . . . . . . . . . . . . .
INSTRUMENT FOR MEASURING POTENTIAL DIFFERENCES IN AN
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EARTHING OF PERMANENTLY WIRED ELECTRICAL EQUIPMENT IN
EP AREAS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CALCULATIONS FOR EQUIPOTENTIAL EARTHING SYSTEMS . . . . . . .
ADDITIONAL REQUIREMENTS FOR APPLICATION IN NEW ZEALAND .

60
61
63
65
68
70


AS/NZS 3003:1999

6

STANDARDS AUSTRALIA / STANDARDS NEW ZEALAND
Australian / New Zealand Standard
Electrical installations — Patient treatment areas of
hospitals and medical and dental practices
S E C T I O N

1

S C O P E

A N D

G E N E R A L

1.1 SCOPE This Standard sets out the requirements for electrical installations in those
patient treatment areas of hospitals and other medical and dental practices in which the
administration or practitioner has elected to —

(a) use medical electrical equipment during cardiac procedures; or
(b) use medical electrical equipment with Type B (unprotected) applied parts during
body type procedures; or

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(c) use multiple pieces of medical equipment with Type BF applied parts during body
type procedures.
The requirements are applicable to the electrical installations and certain conductive items
in those areas.
This Standard sets out additional requirements for electrical installations in patient
treatment areas in hospitals and other medical and dental practices in New Zealand (see
Appendix J).
Patient treatment areas other than body-protected electrical areas or cardiac-protected
electrical areas are not covered by this Standard, but are covered by the relevant
requirements of AS 3000.
NOTES:
1

Attention is drawn to AS/NZS 2500, which outlines the method of determining the
classification of various procedures and recommends routine operational and maintenance
procedures to ensure the safe use and interconnection of medical electrical equipment. That
Standard also explains how several procedures commonly carried out in a general ward area
are classified under certain conditions as cardiac-type procedures warranting extreme
caution.

2

A rationale for the requirements of this Standard is given in Appendix A.

3

If a hospital or medical practice has elected to undertake cardiac-type procedures then
appropriate cardiac-protected electrical areas need to be provided.

4

The number and disposition of cardiac-protected electrical areas that should be provided
will be dependent on the types of procedures that the hospital or medical practice has
elected to undertake.

5

Hospitals and medical practices that might not propose to undertake cardiac-type procedures
may, in the case of emergency, temporarily upgrade an area in accordance with the
recommendations and limitations identified in AS/NZS 2500, to provide temporary electrical
protection.

6

The increasing use and application of medical electrical equipment in medicine and the
range of electrical protection provided by such equipment, ranging from no isolation to full
isolation, makes it difficult to determine which patient treatment areas will require
cardiac-type or body-type electrical protective measures in the electrical installation. It is
therefore recommended that, during any electrical installation in patient treatment areas—
(a) close attention be given to the relevant requirements herein (earthing, subcircuit layout
and other factors) that will facilitate conversion of areas to either body-protected or
cardiac-protected areas;
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7

AS/NZS 3003:1999

(b) attention be given to the recommendations of AS/NZS 2500 listing the electrical supply
and equipment protective measures appropriate for particular medical procedures; and
(c) consideration be given to residual current device (RCD) protection of other patient
treatment areas where equipment to be used will be likely to be subjected to spilling or
splashing of liquids. Areas such as dialysis rooms should always be wired as bodyprotected electrical areas because of the presence and likely spillage of copious
amounts of liquid.
7 It is important for hospital managements and the electrical design engineers to evaluate
jointly the elected procedures likely to be undertaken and to determine which areas of the
installation should be wired as body-protected electrical areas or as cardiac-protected
electrical areas.
8 Requirements for mobile trolleys
AS/NZS 3200.1.0 and AS/NZS 4510.

supporting

electrical

equipment

are

given

in

9 Requirements for emergency lighting are given in AS/NZS 2293.
10 Requirements for emergency power systems in hospitals are given in AS/NZS 3009.

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1.2 APPLICATION Electrical installations in body-protected or cardiac-protected
electrical areas shall be carried out in accordance with the appropriate requirements of
AS 3000 in Australia and the Electricity Regulations in New Zealand, and with the
requirements of this Standard. The requirements include the following:
(a)

(b)

For body-protected and cardiac-protected electrical areas
(i)

Provision of protected power supplies.

(ii)

On isolated circuits, switching in all live conductors, of socket-outlets and
permanently wired equipment.

For cardiac-protected electrical areas
(i)

Additional earthing requirements.

(ii)

In Australia, modified resistance of socket-outlet earthing contacts.

(iii)

Insulation of earthing connections.

(iv)

Particular requirements for the ‘looping in’ of earthing conductors.

(v)

Extra-low voltage (ELV) supply requirements.

This Standard applies to those installations (or alterations or additions thereto) made or
carried out after the date of publication of this Standard. However, hospital management
should carefully evaluate the procedures electively undertaken within existing hospitals
and take steps to implement the requirements specified herein for the appropriate class of
area.
1.3 REFERENCED DOCUMENTS
Standard:
AS
1125

The following documents are referred to in this

Conductors in insulated electric cables and flexible cords

1169

Minimizing of combustion hazards arising from the medical use of flammable
anaesthetic agents

1319

Safety signs for the occupational environment

2293
2293.1

Emergency evacuation lighting for buildings
Part 1: System design, installation and operation

3000

Electrical installations — Buildings, structures and premises (known as the
SAA Wiring Rules)

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AS/NZS 3003:1999

AS
3011
3011.1
3011.2

Electrical installations — Secondary batteries installed in buildings
Part 1: Vented cells

Part 2: Sealed cells

3111

Approval and test specification — Miniature overcurrent circuit-breakers

3147

Approval and test specification — Electric cables — Thermoplastic insulated —
For working voltages up to and including 0.6/1 kV

3190

Approval and test specification — Residual current devices (current-operated
earth-leakage devices)

AS/NZS
2500
3008
3008.1.1
3008.1.2

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8

Guide to the safe use of electricity in patient care
Electrical installations — Selection of cables
Part 1.1: Cables for alternating voltages up to and including 0.6/1 kV —
Typical Australian installation conditions

Part 1.2: Cables for alternating voltages up to and including 0.6/1 kV —
Typical New Zealand installation conditions

3009

Electrical installations — Emergency power supplies in hospitals

3100

Approval and
equipment

3108

Approval and test specification — Particular
transformers and safety isolating transformers

3112

Approval and test specification — Plugs and socket-outlets

3116

Approval and test specification — Electric cables—Elastomer insulated — For
working voltages up to and including 0.6/1 kV

3200
3200.1.0

Medical electrical equipment

Part 1.0: General requirements for safety — Parent Standard

4510

Isolated electrical supply systems for medical use

VDE
0107

test

specification — General

requirements
requirements

for
for

electrical
isolating

Electrical installations in hospitals and locations for medical use outside
hospitals (English language version issued by the British Standards Institution)

1.4 DEFINITIONS
those below apply.

For the purpose of this Standard, the definitions in AS 3000 and

1.4.1 Applied parts, Type CF, Type BF or Type B — applied parts classified Type CF,
Type BF or Type B in accordance with AS 3200.1.0.
1.4.2 Authorized person — the person in charge of the premises, or the licensed
electrical contractor or electrician or other person appointed or selected by the person in
charge of the premises to perform certain duties associated with the electrical installation
on the premises.
1.4.3 Body-protected electrical area — a protected electrical area intended to provide
protection against electric shock following contact with live parts of accessories or
equipment connected to the mains supply (‘macro shock’).
1.4.4 Body-type procedure — a procedure whereby a patient is connected to an item of
medical electrical equipment so that the impedance of the skin is reduced by electrode
paste or by the entrance of conducting fluids, metal needles and saline-filled catheters, but
where direct contact with the heart is not possible, e.g. in extra-thoracic procedures.

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AS/NZS 3003:1999

1.4.5 Cardiac-protected electrical area — a protected electrical area intended to provide
protection against —
(a)

electric shock following contact with live parts of accessories or equipment
connected to the mains supply (‘macro shock’); and

(b)

the inadvertent flow of minute electric currents through an electrical conductor in
contact with a patient’s heart (‘micro shock’).

1.4.6 Cardiac-type procedure — a procedure whereby an electrical conductor is placed
within the heart of a patient or is likely to come into contact with the heart, such
conductor being accessible outside the patient’s body. In this context, an electrical
conductor includes electrical wires such as cardiac pacing electrodes and intracardiac ECG
electrodes, or insulated tubes filled with conducting fluids.
1.4.7 Equipotential terminal (EP terminal) — a terminal provided in cardiac-protected
electrical areas providing a means of connection to the equipotential earthing system.

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1.4.8 Exposed metal — all metal parts of electrical equipment that can be touched with
the jointed test fingers, defined in AS 3200.1.0, other than the following:
(a)

Live parts.

(b)

Parts separated from live parts by double insulation or reinforced insulation.

(c)

Metal nameplates, screw-heads, covers or plates —
(i)

which are supported on or attached or connected to substantial non-conductive
material in such a manner that they cannot become alive in the event of failure

of insulation of live parts; and

(ii)

whose means of fixing cannot come into contact with any internal metal, other
than earthed metal or parts referred to in Item (d), or be exposed to arcing
contact with live parts.

NOTE: ‘Failure of insulation’ in this context is taken to include accidental bridging of an
insulating gap by metal or partially conducting material such as carbon dust or moisture, as
well as breakdown in the conventional sense.

(d)

Parts that are separated from live parts by other metal parts which are themselves
earthed or have double insulation or reinforced insulation.

(e)

Parts within an enclosure, the cover of which requires the use of a tool for its
removal.
NOTE: A key is not considered to be a tool except where special circumstances prevail, e.g.
the use of the key is restricted to technical service personnel having an appropriate level of
electrotechnical training.

(f)

Parts within equipment, the configuration and mass of which are such that the parts
are not accessible during normal use and movement of the equipment.

Non-metallic material which is conductive to a degree that may contribute to a hazardous
condition arising is deemed to be exposed metal, subject to the limitations of Items (a) to
(f).
1.4.9 Leakage protected circuit (LPC) — circuit protected against leakage current by a
leakage protective device.
1.4.10 Leakage protective device (LPD) — a residual current device (RCD) in
accordance with AS 3190 or an isolating transformer device in accordance with AS 4510.
1.4.11 Line isolation monitor (LIM) — an instrument designed to continuously monitor
the prospective hazard current and to actuate an alarm when this current exceeds a preset
level.

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AS/NZS 3003:1999

10

1.4.12 Medical electrical equipment — electrical equipment provided with not more
than one connection to a particular supply mains and intended to diagnose, treat or
monitor the patient under medical supervision; and which makes physical or electrical
contact with the patient, or transfers energy to or from the patient, or detects such energy
transfer to or from the patient.

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NOTES:
1 Examples of diagnostic medical electrical equipment are —
(a) electrocardiographs, electro-encephalographs, electromyographs and
polygraphs; and

(b) X-ray, ultrasonic, gamma ray and infrared organ-imaging equipment.
2 Examples of therapeutic medical electrical equipment are —
(a) electrosurgical equipment;
(b) patient heating and cooling devices;
(c) dialysis machines;
(d) electrically powered or controlled respirators;
(e) electrical injections and pumps, to infuse fluids into the patient; and
(f) electrodental equipment.

multichannel

1.4.13 Overload monitor — an instrument designed to monitor continuously the primary
current of an isolated supply and to actuate an alarm when the current exceeds the rating
of the isolating transformer.
1.4.14

Patient-circuit — an electrical circuit of which the patient forms a part.

1.4.15 Patient equipotential area (EP area) — the patient environment within a
cardiac-protected electrical area in which the potential difference between earthing
connections of particular equipment has been minimized.
Each EP area extends to the distances from the intended location of the patient, as shown
in Figure 1.1, in which intentional or unintentional contact between patient and equipment
or some other person touching the equipment can occur.
Where the perimeters of adjacent EP areas overlap the combined area is deemed to be one
EP area. However, where a bed is placed adjacent to the wall, the EP area does not extend
through the wall.

DIMENSIONS IN MILLIMETRES

FIGURE 1.1

PATIENT EQUIPOTENTIAL AREA (EP AREA)
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1.4.16 Patient equipotential junction (EP junction) — the junction of the EP earthing
system and the return earth.
1.4.17 Patient location — any intended location of the bed, table or seating arrangement
for a patient, whether or not occupied by the patient.
Where the location of a patient undergoing a medical electrical procedure is likely to vary
for different occasions, e.g. in some operating theatres, the patient location extends to the
entire room. This includes locations for incubators or cribs in delivery suites.
1.4.18 Prospective hazard current — current that would flow, in an isolated electrical
supply, between one of the active conductors and earth if the other active conductor were
solidly bonded to earth.
NOTE: Although this current does not flow until a line-to-earth fault occurs, a line can be
described as having a prospective hazard current of a particular value because, as a result of the
cumulative effect of the imperfections in the line isolation, current will flow as soon as a
line-to-earth fault occurs.

1.4.19 Protected electrical area — a patient treatment area that is wired in accordance
with the requirements of this Standard.

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A protected electrical area may contain one or more patient locations if a body-protected
area, or one or more EP areas if cardiac protected.
The boundaries of the protected electrical area extend to the walls enclosing the patient
locations or EP areas or, if such walls are incomplete (e.g. entryway without a door), to
the boundary formed if such walls or projections were extended. The boundary extends to
a height of 2.3 m from the floor on any wall deemed to be in or a boundary of the
protected electrical area. The boundary includes the front facade of any nurses’ station
located in the space but does not extend through or behind this station.
Where all the patient locations enclosed by the boundary described above are not being
wired according to this Standard the protected electrical area shall, as a minimum, extend
to the distances from the intended patient locations as shown in Figure 1.2. The area
described by the locus of the line need not extend through walls.
If an operating theatre, a delivery suite or a day procedure room is to be a protected
electrical area, the whole room is deemed a protected electrical area in accordance with
this Standard.
1.4.20 Return earth — the earthing conductor which connects the EP junction to the
installation earth at the main earthing conductor at the main switchboard, or to the
submain earthing conductor at the distribution board, as appropriate.
1.4.21 Transformer-isolated supply — an a.c. supply in which all the conductors are
isolated from earth by means of an isolating transformer.
1.5 METHOD OF MARKING Marking shall be legible and indelible and shall be
made either on the equipment itself or on a plate securely fixed to the equipment.
Adhesive metallic labels shall not be fixed in locations where, if they become detached,
they may readily touch live parts or bridge insulation.
Plates incorporating a durable surface finish, including those with particulars printed
photographically in conjunction with anodizing, shall be regarded as indelible.
Where marking is by adhesive non-metallic labels, surface transfers, painting, silkscreening printing with etching dyes or similar means, the marking shall be sufficiently
durable for its purpose and located where it will not be subjected to conditions that may
lead to its deterioration, having regard to the quality of marking, the surface to which it is
applied, and service conditions such as temperature, moisture, abrasion and handling.

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DIMENSIONS IN MILLIMETRES

FIGURE 1.2
BOUNDARY OF PROTECTED ELECTRICAL AREA

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S E C T I O N

2

AS/NZS 3003:1999

G U I D A N C E

2.1 INTRODUCTION This Standard sets out the requirements for electrical
installations in patient treatment areas. The selection of which particular patient treatment
areas in hospitals and other medical and dental practices are to be wired according to this

Standard requires careful consideration by the appropriate design, engineering and clinical
staff. Once an area has been designated as requiring one of the specialized wiring systems
set out in this Standard the classification chosen for each area should be based entirely on
consideration of the types of medical procedures to be done in the particular area.
NOTE: Appendix B gives detailed guidance on planning of areas with characteristics of both
RCD and transformer isolated supply systems.

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2.2 AREA SELECTION Only those patient treatment areas in which medical
electrical equipment is routinely used for body-type procedures (see Clause 1.4.4) as
discussed in AS/NZS 2500 need be wired according to this Standard.
Most modern electro-medical equipment used for doing body-type procedures, i.e.
equipment having a type BF or CF applied part, does not need any special wiring for the
procedure to be done safely from an equipment or installation perspective, if a single
piece of equipment is being used. In all procedures safe practice is always necessary.
Recommendations for safe practice are detailed in AS/NZS 2500.
For the purposes of this Section ‘applied parts’ refers only to —
(a)

a transducer which makes contact with the patient;

(b)

an electrode which makes contact with the patient;

(c)

a part which enters the patient; or

(d)

a part which contains liquid which in turn enters the patient.

Areas where the equipment used does not offer any specific patient protection from
electrical hazards, i.e. equipment having a B type applied part as described in Items (a) to
(d), need to be wired according to this Standard. In modern medical practice examples of
this type of equipment are not common; however, some equipment is manufactured with
Type B applied parts, e.g. dialysis machines and arthroscopic shavers. Other examples
might occur in some specialized medical practices.
Other areas that are commonly wired according to this Standard are operating theatres,
intensive and coronary care units, cardiac catherization laboratories, and accident and
emergency rooms.
All other patient areas of a facility, i.e. those where no electro-medical procedures are
routinely done using a type BF or CF applied part, have no specific need to be wired
according to this Standard.
This Standard allows areas wired as body-protected or cardiac-protected to occupy a part
of a defined space or room alongside areas wired according to AS 3000. Minimum
clearance distances between protected and unprotected outlets have been specified to
reduce the possibility of confusion between the power outlets of the two types of areas.
It is strongly recommended that clinical staff responsible for the treatment of patients in
each area of the facility should be consulted when decisions relating to the wiring
requirements of each area are taken.

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2.3 CLASSIFICATION SELECTION Nearly all areas of hospitals and other medical
and dental practices wired according to this Standard will only need to meet the
requirements given for a body-protected electrical area (see Section 3).
Cardiac-protected electrical areas (see Section 4) are required only where there is direct
electrical connection with the patient’s heart. These types of procedures normally only
occur in large acute-care hospitals and are nearly always confined to cardiac
catheterization laboratories, special open heart theatres and high-level intensive care units.
Some other areas will also need to meet the requirements, if cardiac-type procedures are
carried out.
AS/NZS 2500 provides recommendations on establishing temporary cardiac-protected
electrical areas for emergency or short-term use. Only those areas that undertake routine
application of direct electrical connection to a patient’s heart need be wired in accordance
with the cardiac-protected electrical area requirements.

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The additional requirements for cardiac-protected electrical areas, particularly those
associated with the equipotential bonding, result in higher installation costs, especially
where existing areas are being upgraded. Many examples exist of patient treatment areas
that, needlessly, have been wired in accordance with these requirements.

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S E C T I O N 3

B O D Y- P R O T E C T E D
E L E C T R I C A L A R E A S
3.1 GENERAL Body-protected electrical areas shall comply with the requirements
specified in this Section.

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NOTES:
1

Body-protected electrical areas are defined in Clause 1.4.3 and are those medical treatment
areas, other than cardiac-protected electrical areas, which are wired to provide protection
additional to that provided by wiring to AS 3000, for the routine and regular performance of
body-type procedures using medical electrical equipment having Type B (unprotected)
applied parts.

2

Rooms such as ECG, EMG, EEG and physiotherapy rooms should be wired as
body-protected electrical areas unless the management of the hospital or medical practice
has decided to use therein equipment having only Type CF or Type BF patient-circuits.

3

Areas such as dialysis rooms should always be wired as body-protected electrical areas
because of the presence and likely spillage of copious amounts of liquid.

4

AS 1169 contains requirements for antistatic flooring for areas in which flammable

anaesthetics are used.

3.2

SUPPLY WIRING

3.2.1 Low voltage a.c. supplies (including emergency power supplies)
LPDs shall be provided to the following —

Protection by

(a)

All socket-outlets, except those identified in Items (i) and (ii), within the
body-protected electrical area, including those on permanently wired equipment.

(b)

All socket-outlets, except those identified in Items (i) and (ii), located outside the
defined protected electrical area but which would normally be used to power either —

(c)

(i)

equipment located within the area; or

(ii)

equipment brought into the area while still connected to the outlet (e.g. a

mobile X-ray machine).

Permanently wired medical electrical equipment having a Type B applied part
consisting of patient circuits having —
(i)

a transducer which makes contact with the patient;

(ii)

an electrode which makes contact with the patient;

(iii)

a part which enters the patient; or

(iv)

a part which contains a liquid which in turn enters the patient.

Protection by LPDs is not required for —
(i)

socket-outlets installed for the connection of clocks; and

(ii)

ceiling-mounted socket-outlets (and socket-outlets mounted on the wall at the height
of more than 2.3 m) specifically intended for permanently mounted, plug-in
equipment such as patient monitors, TV receivers and airconditioners.

All unprotected socket-outlets located in the vicinity of the protected electrical area shall
be at least 3 m, line-of-sight, from the nearest LPD-protected outlet in the protected area.
All other supply wiring within the body-protected electrical area shall be protected in
accordance with AS 3000.

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NOTES:
1

Characteristics of both RCD-protected and transformer isolated supply systems are detailed
in Appendix B together with pertinent features to be considered when the type of supply
system to be incorporated is chosen.

2

Where ‘mixed systems’ (i.e. RCD-protected points and transformer isolated points) are
installed, attention should be given to the marking requirements of Clause 3.5.2 and to the
need to clearly indicate the type of supply available at any particular point. In addition,
rigorous staff education programs should be undertaken in accordance with the
recommendations of AS/NZS 2500. Where only one type of protection system is
incorporated, i.e. RCD or isolated supply, understanding of the system by the user is less
difficult.

3.2.2 Low voltage d.c. supplies Reticulated low voltage d.c. supplies, including d.c.
emergency supplies, shall not be earth referenced.
NOTE: AS 3011.1 and AS 3011.2 contain requirements for secondary batteries installed in
buildings.

3.2.3 Extra-low voltage supplies Extra-low voltage supplies shall comply with
AS 3000 and shall not have exposed live parts.

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3.3 EARTHING
AS 3000.

Earthing shall be carried out in accordance with the requirements of

3.4 ACCESS TO LEAKAGE PROTECTIVE DEVICES AND LINE ISOLATION
MONITORS The following devices shall be accessible without the use of a key and
shall be located within the body-protected area:
(a)

Test and reset facilities for RCDs.

(b)

Overload monitors for isolating transformers.

Line isolation monitors shall be accessible without the use of a key and shall be located
either within the body-protected area or within the nurses’ station.
The requirements of this Clause need not apply to LPDs provided for floor cleaning
purposes in accordance with Clause 3.5.1.2.

3.5
3.5.1

SOCKET-OUTLETS
Number and disposition

3.5.1.1 General An adequate number of socket-outlets shall be provided in the most
likely location of equipment and all socket-outlets shall be positioned for easy access.
NOTE: Not less than two socket-outlets should be provided at each patient location in a
body-protected electrical area. A larger number of socket-outlets will be necessary in some
patient locations in body-protected electrical areas, to avoid the use of extension cords or
socket-outlet adaptors.

3.5.1.2 Cleaning purposes Where socket-outlets are provided for floor cleaning in
body-protected areas they shall be —
(a)

protected by a LPD; and

(b)

marked, in accordance with Clause 1.5, with the words ‘FLOOR CLEANING
PURPOSES ONLY’.

The LPD protecting this circuit shall not be used to protect socket-outlets intended for use
with medical electrical equipment.
The requirements of Clause 3.4 need not apply to this LPD.
NOTE: This LPD may be used to protect other similar outlets for other body-protected areas.

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3.5.2 Marking and identification of socket-outlets Each socket-outlet or group of
socket-outlets which are remote from the LPD controlling them shall be identified
(numbered or lettered) in a manner which identifies the approprite LIM and overload
monitor or the appropriate RCD. Each socket-outlet or group of socket-outlets supplied
from RCD-protected circuits shall be fitted with an amber, yellow or orange luminous
indicator to indicate that the supply is available. In addition, socket-outlets shall be
marked, in accordance with Clause 1.5 —
(a)

to indicate when the socket-outlet switch is ‘ON’, e.g. by a red-coloured luminous
indicator or red marking; and

(b)

with the words ‘RCD-PROTECTED’ to indicate that the socket-outlet is protected
by an RCD.

Each socket-outlet or group of socket-outlets supplied from an isolating transformer shall
be marked, in accordance with Clause 1.5, with the words ‘ISOLATING
TRANSFORMER PROTECTED’.
In addition, socket-outlets shall be suitably and permanently marked to indicate when the
socket-outlet switch is ‘ON’, e.g. by a red-coloured luminous indicator or red marking.

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The requirements for marking and identification need not apply to socket-outlets provided
for cleaning purposes in accordance with Clause 3.5.1.2.
NOTE: Adjacent socket-outlets constitute a group only if they are all contained within one
contiguous enclosure or panel.

3.5.3 Type of socket-outlet General purpose outlets (GPOs) shall be connected only to
a.c. supply at nominal mains voltage.
Socket-outlets shall be switched in all active conductors.
NOTE: All isolated supply conductors are active conductors.

3.6

RESIDUAL CURRENT DEVICES (RCDs)

3.6.1 General If RCDs are used to satisfy the requirements of Clause 3.2, they shall
comply with AS 3190 and shall have a rated residual current not exceeding 10 mA.
NOTE: The RCD may be combined with the overcurrent protective device required by AS 3000.

3.6.2

Number of poles

Each RCD shall be arranged to switch all live conductors.

NOTE: This requirement is the same as that for RCDs in cardiac-protected electrical areas. It
involves the installation of an RCD which switches all live conductors, gives protection where
the potential of the neutral conductor may be considerably higher than earth potential, and also
facilitates conversion to a cardiac-protected electrical area if this were subsequently required.

3.6.3 Discrimination Each RCD protecting an electrical circuit in a body-protected
electrical area should be discriminatory in its operation, i.e. an earth fault in any one
subcircuit should not cause interruption of the supply to other subcircuits.
3.6.4 Number of points controlled by RCDs Each RCD shall control the supply to
not more than 12 points, i.e. socket-outlets or permanently wired equipment, or
combinations thereof. Attention is drawn, however, to the desirability in certain areas for
fewer points to be controlled by any one RCD.
NOTES:
1

More than one patient location may be controlled by one RCD.

2

In the planning of the number of points to be controlled by an RCD, consideration should be
given to the type and number of equipment to be used and the need to minimize interruption
of supply to any patient location.

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3.6.5 Indication If the location of any RCD is remote from the socket-outlets that it
supplies, the RCD shall be provided with a luminous indicator to show when power is
available to the socket-outlets.
3.6.6 Marking Each RCD and any associated circuit-breaker shall be marked in
accordance with Clause 1.5 to indicate the points that it controls.

3.6.7 Access for testing Where an RCD-protected supply is connected only to
permanently wired equipment, access to the load circuit for testing the operation of the
RCD shall be provided.
This facility shall be legibly and indelibly marked ‘TEST ONLY’ and shall be accessible.
The test facility shall be marked, in accordance with Clause 1.5, to identify the RCD that
it tests.
A socket-outlet may be used, where access to the socket-outlet is by means of a tool.
3.7

LOW VOLTAGE ISOLATED SUPPLIES

3.7.1 General Where provided in accordance with Clause 3.2, the isolated supply shall
comply with the requirements of AS/NZS 4510.

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The isolated supply shall comprise the following:
(a)

Isolating transformer.

(b)

Overload monitor, except where exempted by Clause 3.7.3.

(c)

Line isolation monitor.

For New Zealand, approved resistance-type monitoring systems shall apply. Suitable

resistance-type monitoring systems include systems that comply with VDE 0107.
NOTE: The IEC is developing a Standard for resistance-type monitoring systems.

3.7.2 Isolating transformer The isolating transformer shall be installed in accordance
with the requirements of AS 3000 and the manufacturer’s instructions, in a space or
enclosure so that in normal operation at the rated load, the temperature of the space or
enclosure does not exceed the maximum ambient temperature marked on the isolating
transformer. The isolating transformer manufacturer’s advice should be sought on
installing an isolating transformer in a space or enclosure so that the isolating
transformer’s maximum temperature is not exceeded.
Where an isolating transformer supplies two or more patient locations, duplicate alarms
and controls shall be provided where patient locations are not in direct visual contact.
3.7.3 Overload monitor Each isolated supply shall be provided with an overload
monitor to monitor the isolating transformer current. The alarm point rating of the
overload monitor shall be marked on the monitor, in accordance with Clause 1.5, to
facilitate testing.
This Clause applies to all isolating transformers except those which, because of the
characteristics of the load, are not likely to carry overload current, and which supply only
permanently wired equipment.
NOTE: The overload monitor may be combined with the line isolation monitor required by
Clause 3.7.4.

3.7.4 Line isolation monitor Every isolated supply shall be provided with a line
isolation monitor (LIM) to monitor the prospective hazard current.
It shall not be possible to deactivate the LIM without the use of a tool.
NOTE: The LIM may be combined with the overload monitor required by Clause 3.7.3.

Each LIM shall be identified (numbered or lettered) in a permanent manner which
identifies the points, i.e. socket-outlets or permanently connected equipment, with which it
is associated.

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3.7.5 Overcurrent circuit-breaker The primary circuit of every isolating transformer
shall be protected by a miniature overcurrent circuit-breaker complying with AS 3111.
The rating of the overcurrent circuit-breaker shall not exceed the primary current rating of
the transformer.
NOTE: This miniature overcurrent circuit-breaker may be the same device as the overload
protective device required by AS 3000.

3.7.6 System prospective hazard current The prospective hazard current of the
supply, LIM and circuit wiring, but not including other equipment intended for connection
to the circuit, shall not exceed 2 mA, when measured in accordance with AS/NZS 4510.
NOTES:
1

Metallic conduit provides some protection against electrical interference and may be used,
provided that it does not cause the prospective hazard current to exceed that permitted by
this Clause.

2

The length of isolated supply circuits should be as short as practicable in order to minimize
the total prospective hazard current.

3.7.7 Number and disposition The maximum number of points that may be connected
to a final subcircuit supplied from an isolated supply shall be determined in accordance
with AS 3000.
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NOTE: Separate supplies may need to be provided to each patient location in order to—
(a)

reduce the size of the transformer and the magnitude of the prospective hazard current;

(b)

limit the complexity of the installation; and

(c)

obviate any duplication of alarms and controls.

3.7.8 Access for testing Where an isolating-transformer-protected supply is connected
only to permanently wired equipment, access for testing the operation of the LIM shall be
provided. This facility shall be marked, in accordance with Clause 1.5, ‘TEST ONLY’ and
shall be accessible. The test facility shall be marked, in accordance with Clause 1.5, to
identify the LIM that it tests.
A socket-outlet may be used where access to the socket-outlet is by means of a tool.
3.8 ISOLATING SWITCHES Each item of permanently wired equipment supplied by
a leakage-protected circuit shall be provided with an individual isolating switch that shall
operate in all live conductors.
3.9 MARKING A prominent notice complying with the requirements of Appendix C
shall be affixed in body-protected electrical areas, at a height approximately 2 m above
floor level, to indicate the status of the area.

NOTE: Means for the recording thereon of the most recent test date and the authorized person’s
signature are also recommended.

3.10 COMMISSIONING Body-protected electrical areas shall be subjected to the
relevant testing and inspections listed in Appendix D, prior to commissioning of the area.

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S E C T I O N 4
C A R D I A C - P R O T E C T E D
E L E C T R I C A L A R E A S
4.1 GENERAL Cardiac-protected electrical areas shall comply with the requirements
specified in this Section.

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NOTES:
1

Cardiac-protected electrical areas are defined in Clause 1.4.5. They are the only treatment
areas which are wired to provide protection and equipotential measures for undertaking
cardiac-type procedures.

2

During the design and installation phases consideration should be given to measures which
minimize interference from magnetic fields. This interference may cause a dangerous
situation for the patient or may cause incorrect measurements. Guidance on measures for
avoiding interference from magnetic fields is given in Appendix E. A method for measuring
magnetic fields is given in Appendix F. Other methods and instruments may be used.

3

If a hospital has elected to undertake cardiac-type
cardiac-protected electrical areas will be provided.

4

The cardiac-protected electrical areas which should be provided will depend on the types of
procedures which the hospital has elected to undertake. Some areas, such as cardiac
catheterization laboratories and operating theatres where thoracotomies are to be undertaken,
will always be cardiac-protected electrical areas.

procedures

then appropriate

Other areas, including operating theatres in the same suite, need not be wired as
cardiac-protected electrical areas, unless it is intended to carry out cardiac-type procedures
therein.
5

Hospitals which may not propose to undertake cardiac-type procedures may, in the case of
emergency, temporarily upgrade an area in accordance with the recommendations and
limitations identified in AS/NZS 2500, to provide temporary protection.

6

AS 1169 contains requirements for antistatic flooring for areas in which flammable
anaesthetics are used.

4.2

SUPPLY WIRING

4.2.1 Low voltage a.c. supplies (including emergency power supplies)
LPDs shall be provided to the following:

Protection by

(a)

All socket-outlets within the cardiac-protected electrical area, including those on
permanently wired equipment.

(b)

All socket-outlets located outside the defined protected electrical area but which
would normally be used to power either —

(c)

(i)

equipment located within the area; or

(ii)

equipment brought into the area while still connected to the outlet (e.g. a
mobile X-ray machine).

Permanently wired medical electrical equipment having a Type B applied part
consisting of patient circuits having —
(i)

a transducer which makes contact with the patient;

(ii)

an electrode which makes contact with the patient;

(iii)

a part which enters the patient; or

(iv)

a part which contains a liquid which in turn enters the patient.

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Protection by LPDs is not required for the following:
(i)

Fixed X-ray installations which comply with the safety requirements of the
appropriate part of AS 3200 unless they incorporate a Type B applied part
consisting of —

(ii)

(A)

a transducer which makes contact with the patient;

(B)

an electrode which makes contact with the patient;

(C)

a part which enters the patient; or

(D)

a part which contains liquid which in turn enters the patient.

Socket-outlets installed for the connection of clocks.

(iii) Ceiling-mounted socket-outlets (and socket-outlets mounted on the wall at the
height of more than 2.3 m) specifically intended for permanently mounted, plug-in

equipment such as patient monitors, TV receivers and airconditioners.
All unprotected socket-outlets located in the vicinity of the protected electrical area shall
be at least 3 m, line-of-sight, from the nearest LPD-protected outlet in the protected area.
All other supply wiring within the cardiac-protected electrical area shall be protected in
accordance with AS 3000.
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NOTES:
1

Characteristics of both RCD-protected and transformer-isolated supply systems are detailed
in Appendix B together with pertinent features to be considered when the type of supply
system to be incorporated is chosen.

2

Where ‘mixed systems’ (i.e. RCD-protected points and transformer isolated points) are
installed, attention should be given to the marking requirements of Clause 3.5.2 and to the
need to indicate clearly the type of supply available at any particular point. In addition,
rigorous staff education programs should be undertaken in accordance with the
recommendations of AS/NZS 2500. Where only one type of protection system is
incorporated, i.e. RCD or isolated supply, understanding of the system by the user is less
difficult.

3

Consideration should be given to the protection of other electrical equipment by LPDs as
the equipotential earthing system requirements of LPD protected circuits may be less
onerous than those for unprotected circuits.

4

A summary of the protection to be provided to wiring in a cardiac-protected area is shown
in Figure 4.1.

4.2.2 Low voltage d.c. supplies Reticulated low voltage d.c. supplies, including low
voltage d.c. emergency supplies, shall not be earth referenced.
4.2.3 Extra-low voltage supplies Where an ELV supply is earth referenced it shall be
protected by an RCD complying with Clause 4.6.
Where an ELV supply is not earth referenced and is reticulated to more than one socketoutlet it shall be monitored by a LIM.
It shall not be possible to deactivitate the LIM without the use of a tool.
NOTE: The LIM may be combined with the overload monitor required by Clause 4.7.3.

Each LIM shall be identified (numbered or lettered) in a permanent manner which
identifies the points, i.e. socket-outlets or permanently wired equipment, with which it is
associated.
Transformers associated with ELV supplies shall comply with AS/NZS 3108 or the supply
shall comply with Paragraph H3, Appendix H.
ELV supplies shall not have exposed live parts.

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4.3

22

EARTHING

4.3.1 General Earthing shall be carried out in accordance with the requirements of
AS 3000, and with the variations given in Clauses 4.3.2 to 4.3.4.5. Appendix J gives an
alternative method applicable to New Zealand for compliance with Clause 4.3.
The minimum size of any equipotential earthing system conductor shall be not less than
that required by AS 3000.
NOTES:
1 These requirements do not imply a second earthing system but specify more stringent
requirements to those in AS 3000 (see Figure 4.2).
2 The purpose of adopting these more stringent requirements is to limit to 100 mV the
potential difference between simultaneously accessible metal parts. Details of a measuring
instrument for testing potential differences in the installation are given in Appendix G.
3 The equipotential earthing system conductors required by this Standard are intended to limit
the potential difference between earthed points in a cardiac protected area to 100 mV and
are additional to equipotential bonding conductors required by AS 3000.

4.3.2

Equipotential earthing system

4.3.2.1 Provision of equipotential earthing system
only one equipotential earthing system.

Each EP area shall be provided with

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NOTE: One equipotential earthing system may serve more than one EP area.

4.3.2.2

Form of EP system

One of two forms of EP system shall be used, as follows:

(a)

An insulated system shall be used for earthing only protected items set out in
Clause 4.3.2.4. This system shall achieve the resistance values specified in
Clause 4.3.2.4 and shall comply with Item (c). The earthing of items detailed in
Clause 4.3.2.5 shall be carried out as specified in that Clause.

(b)

An insulated earthing system shall be used for earthing all the items set out in
Clauses 4.3.2.4 and 4.3.2.5. This system shall have a cross-sectional area such that
the resistance between any item connected to the system and the EP junction shall
not exceed 0.01 ohms. This system shall comply with Item (c).

(c)

An equipotential earthing system shall be provided with only an EP junction (see
Clause 4.3.2.7). All supply earthing conductors shall first terminate at the EP
junction. All equipment protective earthing conductors shall terminate at the EP
junction.

NOTES:
1 The equipotential earthing system may be any shape or form of conductor.
2 The configuration of the equipotential earthing system is not a mandatory requirement of
this Standard. The equipotential earthing system should be located for convenience of access

(particularly access for testing to the EP junction) and so that any branches thereof can be
kept as short as practicable.
3 The equipotential earthing system may describe any practicable route provided that it
complies with the other requirements of this Section.
4 Consideration should be given to the cross-sectional area of the return earth and the location
of the EP junction in areas in which fixed equipment (e.g. X-ray equipment) is to be
installed which may require larger current-carrying capacity conductors, to comply with —
(i)
the requirement of Item (b) that an equipotential earthing system shall be provided
with only one EP junction and one return earth conductor;
(ii)
the requirements of Clause 4.3.2.3 regarding the minimum cross-sectional area of the
equipotential earthing system; and
(iii)
the requirements of AS 3000 regarding the relationship between the cross-sectional
area of supply conductors and the protective earthing conductor.

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