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Title / Demonstrate familiarity withcommon faults, relay systems, and components of diagrams in power system protection systems
Level / 3 / Credits / 4
Purpose / People credited with this unit standard are able to: describe the different types of faults managed by power system protection systems; describe common types of protection relays operated by the faults; and identify the components in power system protection diagrams.
Classification / Electricity Supply > Electricity Supply - Power System Maintenance
Available grade / Achieved
Explanatory notes
1Performance and work practices in relation to the outcomes and evidence requirements must comply with all current legislation, the Electricity Act 1992, regulations, and codes of practice recognised under that statute; Health and Safety at Work Act 2015, the Resource Management Act 1991, electricity supply industry codes of practice and documented enterprise procedures and any subsequent amendments. These include updated versions of the Safety Manual – Electricity Industry (SM-EI) Wellington: Electricity Engineers’ Association. A full list of current legislation and industry codes is available from
2Definition
Protection systems may include those associated with prime movers, generators, transformers, bus work and distribution networks including: fault detection systems, shutdown and alarm initiation systems, electrical protective relays, voltage and current transformers, field devices, transducers, programmable logic controllers, computers, and alarm annunciation systems.
3Sources of informationinclude but are not limited to the International Electrotechnical Commission (IEC),the Institution of Engineering and Technology (IET), the American National Standards Institute (ANSI), and the Deutsches Institut für Normung e. V. (DIN).
Outcomes and evidence requirements
Outcome 1
Describe the different types of faults managed by power system protection systems.
Evidence requirements
1.1Thedifferent causes of faults, and characteristics of faults associated with each cause are described.
Rangecauses include – electrical or mechanical failure, overload, lightning, wind, fire.
1.2The types of faults likely to occur in installations and equipment found in the generation, transmission, and distribution sectors are described.
Rangeat least three faults from one of – generation, transmission, distribution sectors.
1.3Definitions of common termsassociated with protection systems are described.
Rangecommon terms include but are not limited to –stability, discrimination, speed of operation, sensitivity, back-up protection, inverse-time characteristics, definite-time characteristics.
Outcome 2
Describe common types of protection relays operated by the faults.
Evidence requirements
2.1The different types of common protection relays that may be used to provide power system protection are described and their fault codes are identified.
Rangeat least three different types of common protection relays and their fault codes.
2.2Theboundaries of protection are described.
Rangeincludes but is not limited to – unit protection, non-unit protection.
Outcome 3
Identify the components in power system protection diagrams.
Evidence requirements
3.1The protection system components in diagrams are identified.
Rangecomponents are identified in at least one protection system diagram from one of – generation, transmission, distribution sectors.
Planned review date / 31 December 2021Status information and last date for assessment for superseded versions
Process / Version / Date / Last Date for AssessmentRegistration / 1 / 19 April 2012 / 31 December 2019
Review / 2 / 16 March 2017 / N/A
Consent and Moderation Requirements (CMR) reference / 0120
This CMR can be accessed at
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 ITO (Connexis) if you wish to suggest changes to the content of this unit standard.
Infrastructure ITOSSB Code 101813 / New Zealand Qualifications Authority 2018