NZQA registered unit standard
18274 version 4
Page 1 of 4
Title
Demonstrate knowledge of electricity supply networks
Level
3
Credits
8
Purpose
People credited with this unit standard are able to demonstrate
knowledge of: the principles of electricity transmission,
distribution and reticulation; and switching stations, substations
and associated equipment.
Classification
Electricity Supply > Electricity Supply - Core Skills
Available grade
Achieved
Explanatory notes
1
This unit standard is intended for assessment off-job. The range statements across
the unit standard can be applied according to industry specific equipment,
procedures, and processes.
2
Safety of personnel and plant must be a priority throughout the assessment. If the
safety requirements are not met the assessment must stop and the candidate will be
assessed as not yet competent.
3
Performance and work practices in relation to the outcomes and evidence
requirements must comply with all current legislation, especially the Electricity Act
1992 and any subsequent amendments, and any regulations, codes of practice
recognised under that statute, Health and Safety in Employment Act 1992, the
Resource Management Act 1991, and their subsequent amendments, electricity
supply industry codes of practice and documented enterprise procedures. These
include, Safety Manual – Electricity Industry (SM-EI) (2004) Wellington: Electricity
Engineers’ Association.
A full list of current legislation and industry codes is available from:
Infrastructure Industry Training Organisation
PO Box 1245
HAMILTON.
4
The phrase in accordance with industry requirements is implicit in all outcomes and
evidence requirements in this unit standard.
5
Definitions
Industry requirements include all asset owner requirements; manufacturers’
specifications; and enterprise requirements which cover the documented workplace
policies, procedures, specifications, business, and quality management requirements
relevant to the workplace in which assessment is carried out.
Infrastructure Industry Training Organisation
SSB Code 101813
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
18274 version 4
Page 2 of 4
Asset owner refers to the owner of an electricity supply network that takes its point of
supply from Transpower NZ, and delivers electricity to industrial, commercial and
residential customers.
Asset owner standards are the approved documented work site methods for carrying
out work on an electrical supply network to the standard required by the asset owner.
6
Candidates are expected to recognise where particular items of electricity networks
plant and equipment are in the overall supply system.
7
This unit standard excludes the detailed knowledge of electricity networks plant and
equipment items.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of the principles of electricity transmission, distribution and
reticulation.
Evidence requirements
1.1
The concept of conductor current carrying capacity is explained in terms of
conductor cross-sectional area, current density, conductor resistance, heating,
and heat flow balance.
1.2
Describe the construction of cables used in electricity industry.
Range
may include but is not limited to – Neutral Screen (NS), Mineral
Insulated Metal Sheath (MIMS), Steel Wire Armoured (SWA),
Paper Insulated (PI), Polymeric, Cross-Linked Polyethylene
(XPLE);
evidence of three is required.
1.3
The Multiple Earth Neutral (MEN) system of supply in New Zealand is
explained.
1.4
The concept of referencing in a MEN system to the general mass of earth is
explained in terms of safety, insulation levels, and protection.
1.5
The requirement for insulation of conductors in electrical systems is explained in
terms of safety, segregation of conductors of differing phases, and insulation
coordination.
1.6
The relationship of line voltage to phase voltage to earth is defined in terms of
delta, star phasors, and 3 factor.
1.7
Common transmission line voltages used in New Zealand are defined in terms
of 220 kV, 110 kV, 66 kV, and 33 kV.
1.8
Common sub-transmission, distribution and reticulation line voltages used in
New Zealand are defined in terms 66 kV, 33 kV, 22 kV, 11 kV, 400 V and
230 V.
Infrastructure Industry Training Organisation
SSB Code 101813
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
18274 version 4
Page 3 of 4
1.9
The basic principles of high voltage direct current (HVDC) transmission is
explained with reference to the inter-island link.
1.10
Common overhead power line and power cable configurations are described in
terms of single phase and three phase conductors, bundle conductors,
insulators, towers, poles, cross-arms, and earthing conductors.
Outcome 2
Demonstrate knowledge of switching stations, substations and associated equipment.
Evidence requirements
2.1
The detection of fault currents and principles of overcurrent and earth fault
protective relays are described in terms of current transformers, protective
relays, definite time, and inverse time.
2.2
The use of disconnectors and earth switches are explained in terms of the
isolation and earthing of conductors and plant.
2.3
Common switching station and circuit layouts are described in terms of single
and double busbar, duplicate feeders, and ring feeders.
2.4
Standard sub-transmission and distribution substation configurations are
described in terms of high voltage switchgear, transformer(s), low voltage
switchgear, protection equipment, and local transformer.
2.5
Standard means of remote control of switching stations and substations are
described in terms of supervisory control and data acquisition, and use of
telecommunications.
Planned review date
31 December 2018
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
27 April 2001
31 December 2016
Review
2
22 October 2003
31 December 2016
Rollover and
Revision
3
16 July 2010
Review
4
20 March 2014
31 December 2016
N/A
Consent and Moderation Requirements (CMR) reference
0120
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Infrastructure Industry Training Organisation
SSB Code 101813
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
18274 version 4
Page 4 of 4
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 (CMR). 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 Infrastructure Industry Training Organisation at
qualifications@infrastructureito.org.nz if you wish to suggest changes to the content of this
unit standard.
Infrastructure Industry Training Organisation
SSB Code 101813
 New Zealand Qualifications Authority 2016