NZQA registered unit standard
26740 version 1
Page 1 of 8
Title
Demonstrate and apply intermediate underpinning knowledge of
electrical apparatus in explosive atmospheres
Level
4
Purpose
Credits
5
This unit standard covers the essential underpinning
knowledge for people working with or intending to work with
electrical apparatus in explosive atmospheres.
People credited with this unit standard are able to demonstrate:
 knowledge of hazardous areas installation and maintenance
preparation techniques;
 knowledge of the relationship between explosion-protected
apparatus, certification documentation, and required
apparatus installation locations for installation as given in
specifications and layout drawings and/or written
instructions;
 knowledge of installation Standards and requirements
applicable to explosive atmospheres;
 knowledge of maintenance procedures required in
hazardous areas that ensure the integrity of the explosionprotection technique;
 knowledge of cable termination types suitable for use in
hazardous areas;
 cable terminating methods suitable for use with various
protection techniques in hazardous areas environments;
 knowledge of documents that show the classification of a
hazardous area;
 knowledge of selection and checking of apparatus, wiring,
and accessories suitable for use in explosive atmospheres;
 knowledge of cables and cable selection suitable for use in
explosive atmospheres;
 knowledge of hazardous areas installation design
documentation; and
 knowledge of common and specific hazardous areas for
which classification examples are given in Standards.
Classification
Explosive Atmospheres > Electrical Apparatus in Explosive
Atmospheres - Operations
Available grade
Achieved
ElectroTechnology Industry Training Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
26740 version 1
Page 2 of 8
Entry information
Critical health and
safety prerequisites
Unit 26739, Demonstrate introductory underpinning knowledge
of electrical apparatus in explosive atmospheres, or
demonstrate equivalent knowledge and skills.
Explanatory notes
1
This unit standard has been designed for training and assessment off-job.
2
References
AS/NZS 1768:2007, Lightning protection;
AS/NZS 3000:2007, Electrical installations (known as the Australian/New Zealand
Wiring Rules);
AS/NZS 4761.1:2008, Competencies for working with electrical equipment for
hazardous areas (EEHA) Part 1 – Competency standards;
AS/NZS 4761.2:2008, Competencies for working with electrical equipment for
hazardous areas (EEHA) Part 2 – Guide to assessing competency;
AS/NZS 60079.0:2008, Explosive atmospheres – Equipment – General
requirements;
AS/NZS 60079.10.1:2009, Explosive atmospheres – Classification of areas –
Explosive gas atmospheres;
AS/NZS 60079.14:2009, Explosive atmospheres – Electrical installations design,
selection and erection;
AS/NZS 60079.17:2009, Explosive atmospheres – Electrical installations inspection
and maintenance;
AS/NZS 60079.29.2:2008, Explosive atmospheres – Gas detectors – Selection,
installation, use and maintenance of detectors for flammable gases and oxygen;
AS/NZS 61241.0:2005, Electrical apparatus for use in the presence of combustible
dust – General requirements;
AS/NZS 61241.2.1:2000, Electrical apparatus for use in the presence of combustible
dust – Test methods – Methods for determining the minimum ignition temperature of
dust;
AS/NZS 61241.10:2005, Electrical apparatus for use in the presence of combustible
dust – Classification of areas where combustible dusts are or may be present;
AS/NZS 61241.14:2005, Electrical apparatus for use in the presence of combustible
dust – Selection and installation;
Electricity Act 1992;
Electricity (Safety) Regulations 2010;
Hazardous Substances and New Organisms Act 1996;
Health and Safety in Employment Act 1992, and associated regulations;
and their subsequent amendments and replacements.
3
Definitions
Certification documentation – document(s) that assure(s) the conformity of a product,
process, system, person, or organisation with specified requirements.
Explosion-protection techniques – techniques applied to the design of electrical
apparatus, components, and systems to prevent the electrical energy from becoming
an ignition source in the presence of flammable vapours and gases or combustible
dusts in explosive atmospheres. See explosion-protected apparatus.
ElectroTechnology Industry Training Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
26740 version 1
Page 3 of 8
Explosion-protected apparatus – electrical apparatus to which specific measures are
applied to avoid ignition of a surrounding explosive atmosphere. Such apparatus
employs one or more of the following explosion-protection techniques:
For gas and vapour atmospheres
Ex d – flameproof;
Ex e – increased safety;
Ex i – intrinsic safety; with levels of protection Ex ia, Ex ib and Ex ic;
Ex n – non-sparking;
For dusts
Ex iD – intrinsic safety (dusts);
Ex tD – enclosed;
Others, less common
Ex p – pressurisation; Ex pD (dust);
Ex m – encapsulation, with levels of protection Ex ma, Ex mb, Ex mc (gases and
vapours), and Ex mD (dusts);
Ex s – special protection; categorised by Zone of application; e.g. ‘Ex s
(Zone 0);
Ex o – oil immersion;
Ex q – sand filled;
Ex v – ventilation.
The term equipment includes apparatus, as mentioned in many relevant Standards.
Explosive atmosphere – volatile substances mixed with air under atmospheric
conditions in the form of gases, vapours, mist, or dust in which, after ignition has
occurred, combustion spreads to the entire unburned mixture.
Hazardous area – area in which an explosive atmosphere is present or may be
expected to be present in quantities such as to require special precautions for the
construction, installation, and use of apparatus.
Inspection – scrutiny with or without partial dismantling, and if necessary,
measurement to reach a conclusion on the condition of the apparatus: there are
various types and grades of inspection.
SWA – steel-wire armoured.
Verification dossier – a set of documents showing the complete compliance history of
electrical apparatus and installations within hazardous areas, as defined in
Standards.
4
Range
a Assessment is to take account of variations between the industry sectors and
enterprises. For example, apparatus used in underground coal mining will be
different in some respects from that used in a petrochemical plant.
b All activities and evidence presented for all outcomes and evidence requirements
in this unit standard must be in accordance with safe working principles and
practices, legislation, policies, procedures, ethical codes and Standards, safe and
sound practice, and industry practice; and, where appropriate, manufacturers’
instructions, specifications, and data sheets.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of hazardous areas installation and maintenance preparation
techniques.
ElectroTechnology Industry Training Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
26740 version 1
Page 4 of 8
Evidence requirements
1.1
Occupational Safety and Health (OSH) procedures to be followed when working
in a hazardous area are identified.
1.2
The significance of information provided on the certification documentation and
schedules for a given item of explosion-protected apparatus is described.
1.3
The purpose of a verification dossier and the documentation that should be
contained within it are described.
1.4
Limitations that apply to the use of tools and testing devices in hazardous areas
are explained.
Outcome 2
Demonstrate knowledge of the relationship between explosion-protected apparatus,
certification documentation, and required apparatus installation locations for installation as
given in specifications and layout drawings and/or written instructions.
Evidence requirements
2.1
The purpose of markings on the compliance plate and certification
documentation for a given item of explosion-protected apparatus is explained.
2.2
Procedures required for matching explosion-protected apparatus with
certification documentation and the apparatus specified for an installation are
explained.
2.3
The location of the items of explosion-protected apparatus for an installation is
identified from specifications and layout drawings and/or instructions.
2.4
Methods of identifying explosion-protected apparatus from the Ex symbol
marked on the apparatus, including old apparatus and apparatus certified in
other countries, are described.
Outcome 3
Demonstrate knowledge of installation Standards and requirements applicable to explosive
atmospheres.
Evidence requirements
3.1
The use of installation Standards in determining the requirements with which
the design of explosion-protected apparatus shall comply is explained.
3.2
Wiring systems permitted and not permitted in or above explosive atmospheres
are identified.
3.3
Apparatus types not permitted in or above explosive atmospheres are identified.
ElectroTechnology Industry Training Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
26740 version 1
Page 5 of 8
3.4
Regulations and Standards to which explosion-protected apparatus and wiring
installed in hazardous areas must comply are explained in terms of their
application.
3.5
Installation documentation and records including certification are described.
Outcome 4
Demonstrate knowledge of maintenance procedures required in hazardous areas that
ensure the integrity of the explosion-protection technique.
Evidence requirements
4.1
The purpose of a maintenance schedule is described in accordance with
relevant Standards.
4.2
The purpose of an inspection schedule is described in accordance with relevant
Standards.
4.3
The purpose and extent of the different types and grades of inspections are
explained.
Range
types – initial, periodic, sample;
grades – visual, close, detailed.
4.4
The significance of information provided in a maintenance schedule is
described.
4.5
The impact of environmental conditions on explosion-protected apparatus is
explained.
Range
4.6
includes but is not limited to – corrosion, frequency of
maintenance.
The documentation requirements for recording the maintenance process and
results are explained.
Outcome 5
Demonstrate knowledge of cable termination types suitable for use in hazardous areas.
Evidence requirements
5.1
Explosion-protection features of cable termination devices are described.
5.2
Selection of compliant cable termination devices for given situations and
environments is described.
Outcome 6
Demonstrate cable terminating methods suitable for use with various explosion-protection
techniques in hazardous areas.
ElectroTechnology Industry Training Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
26740 version 1
Page 6 of 8
Evidence requirements
6.1
Conduit systems including seals to meet hazardous areas requirements are
installed.
6.2
Cable with a barrier gland is terminated.
6.3
Multipair, SWA, overall screened, and individual screened cable are terminated
into an enclosure.
6.4
Termination and connections of installed cables/circuits are tested.
Outcome 7
Demonstrate knowledge of documents that show the classification of a hazardous area.
Evidence requirements
7.1
Methods used for classifying hazardous areas are described.
7.2
Delineation of zones, temperature classes, and gas groups of a given
hazardous areas from classification documents are interpreted.
7.3
The delineation of zones, temperature classes, and gas groups of a given
hazardous area from similar situations previously classified, such as those
given in Standards, are interpreted.
7.4
Situations where classification needs to be undertaken and documented by a
person competent in non-specific area classification are identified.
Outcome 8
Demonstrate knowledge of selection and checking of apparatus, wiring, and accessories
suitable for use in explosive atmospheres.
Evidence requirements
8.1
Explosion-protected apparatus and accessories to suit the requirements of
given hazardous areas are identified.
Range
8.2
Wiring systems to suit the requirements of a hazardous area are described.
Range
8.3
three of – Zone 0, Zone 1, Zone 2, Zone 20, Zone 21, Zone 22.
load and duty requirements, capacitive/inductive effects,
inductance/resistance ratio.
Earthing and equipotential bonding requirements for a hazardous area
installation are explained.
ElectroTechnology Industry Training Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
26740 version 1
Page 7 of 8
8.4
Procedures used to check the compliance certification of apparatus used in a
hazardous area are described.
8.5
Electrical protection systems and devices appropriate to an explosion-protection
technique are identified.
Range
8.6
may include but is not limited to – overloads, earth fault protection;
evidence of two is required.
Cable termination devices, including glands, used in explosive atmospheres are
described.
Outcome 9
Demonstrate knowledge of cables and cable selection suitable for use in explosive
atmospheres.
Evidence requirements
9.1
Wiring systems and their applications within hazardous areas are described.
9.2
Selection and use of cable glands, reducers, and blanking elements for
hazardous areas are described.
9.3
Cables are described in terms of their construction, the materials they are made
of, their characteristics, and the environments in which they are to be used.
Range
includes but is not limited to – fireproof, chemical resistant, impact
resistant, flexible, fixed.
9.4
Potential problems resulting from incorrect cable selection are outlined.
9.5
Procedure to make up an SWA cable and gland assembly for a given explosive
environment is described.
9.6
An SWA cable and gland assembly are made up in accordance with
manufacturers’ specifications.
Outcome 10
Demonstrate knowledge of hazardous areas installation design documentation.
Evidence requirements
10.1
Items to be included in the design documentation for a hazardous area
installation are identified.
10.2
Installation layout, specification, work schedule, and other documentation
required for inclusion in a verification dossier is described.
10.3
Essential documentation to be supplied by manufacturers with explosionprotected apparatus and/or accessories is identified.
ElectroTechnology Industry Training Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
26740 version 1
Page 8 of 8
Outcome 11
Demonstrate knowledge of common and specific hazardous areas for which classification
examples are given in Standards.
Evidence requirements
11.1
Examples of hazardous areas classifications given in Standards are explained.
11.2
The application of hazardous areas classifications given in Standards to similar
situations for the purpose of planning electrical installations in hazardous areas
are described.
Planned review date
31 December 2016
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
20 May 2011
N/A
Consent and Moderation Requirements (CMR) reference
0003
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA,
before they can report credits from assessment against unit standards or deliver courses
of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies
to this standard are outlined in the Consent and Moderation Requirements (CMRs). The
CMR also includes useful information about special requirements for organisations wishing
to develop education and training programmes, such as minimum qualifications for tutors
and assessors, and special resource requirements.
Comments on this unit standard
Please contact the ElectroTechnology Industry Training Organisation (ETITO)
reviewcomments@etito.co.nz if you wish to suggest changes to the content of this unit
standard.
ElectroTechnology Industry Training Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016