18274 Demonstrate Knowledge of Electricity Supply Networks

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 Ó New Zealand Qualifications Authority 2018 SSB Code 101813 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.

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 31 December 2016 3 16 July 2010 Revision Review 4 20 March 2014 N/A

Consent and Moderation Requirements (CMR) reference 0120 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 (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 [email protected] if you wish to suggest changes to the content of this unit standard.

Infrastructure Industry Training Organisation Ó New Zealand Qualifications Authority 2018 SSB Code 101813