Level 5
6985 version 4
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Credits 10
Purpose People credited with this unit standard are able to analyse and plan, repair and overhaul, test, and report the repair and overhaul of power transformers of 5kVA and above.
Subfield Electricity Supply
Domain
Status
Status date
Date version published
Planned review date
Entry information
Electricity Supply - Power System Maintenance
Registered
11 December 2009
11 December 2009
31 December 2014
Prerequisites: Unit 2395, Select, use and care for, engineering hand tools ; and Unit 2396, Select, use and maintain portable hand held engineering power tools ; or demonstrate equivalent knowledge and skills.
Accreditation Evaluation of documentation and visit by NZQA and industry.
Standard setting body (SSB) Electricity Supply Industry Training Organisation
Accreditation and Moderation Action Plan (AMAP) reference 0120
This AMAP can be accessed at http://www.nzqa.govt.nz/framework/search/index.do
.
Special notes
1 This unit standard is intended for, but not restricted to, workplace assessment. The range statements within 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.
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3 Performance and work practices in relation to the elements and performance criteria must comply with all current legislation, especially the Electricity Act 1992, and any regulations and codes of practice recognised under that statute; the Health and
Safety in Employment Act 1992; and the Resource Management Act 1991.
Electricity supply industry codes of practice and documented industry procedures include the Safety Manual – Electricity Industry (SM-EI) (2004) Wellington: Electricity
Engineers’ Association. A full list of current legislation and industry codes is available from the Electricity Supply Industry Training Organisation, PO Box 1245,
Waikato Mail Centre, Hamilton 3240.
4 The phrase in accordance with industry requirements is implicit in all elements and performance criteria in this unit standard.
5 Industry requirements include all as set owner requirements; manufacturers’ specifications; and enterprise requirements which cover the documented workplace policies, procedures, specifications, and business and quality management requirements relevant to the workplace in which assessment is carried out.
6 The term repair and overhaul includes fault finding and corrective work, and minor modifications to generation plant and equipment.
7 This unit standard includes single phase, three phase, auto, generator earthing transformers and all associated ancillary equipment within or attached to transformers.
8 This unit standard excludes all external connections and supplies to transformer power and control terminals, cooling water drain and/or inlet connection, and electrical protection relays.
Element 1
Analyse and plan the repair and overhaul of power transformers of 5kVA and above.
Range maintenance records, scope of work, resources, specifications, work plans, drawings, identification of hazards.
Performance criteria
1.1 The need to repair and overhaul is determined.
Range includes but is not limited to – defect notification, condition monitoring, failure, trip, loss of performance.
1.2 Work plans are prepared.
Range prepared plans identify all necessary procedures and resources required for the service.
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1.3 Work plans and specifications are complete, concise, and legible, and reflect identified risk with hazards being identified and eliminated, isolated, or minimised.
1.4 Work plans and specifications are made available for all personnel involved in implementing the plans within the scheduled timeframe.
Element 2
Repair and overhaul power transformers of 5kVA and above.
Range bushings, windings, cores, tap changer cooling system, control and indication, seismic restraints, conservator tanks, tanks, pumps, fans, floats, drains,
2.1 sampling cocks, thermometer, temperature analogue, explosion vent, Buchholz relay, breather.
Performance criteria
Isolations are checked.
2.2 Power transformers requiring repair and overhaul are identified, analysed, and condition determined.
2.3 Power transformers are repaired and overhauled.
Range includes but is not limited to – drain insulating oil, dis-assemble transformers into component parts, inspect component parts for defects, locate, identify and diagnose defects, assess the need for repair or replacement, adjust and/or rectify and/or repair defective components, manufacture or procure replacement components, clean, reassemble components into transformers, refill with oil; may also include – vacuum dry out, streamline oil filtering.
2.4 Repair and overhaul activities and resources are co-ordinated throughout the duration of the work to minimise disruption to personnel, plant, electricity generation, and the environment.
Element 3
Test power transformers of 5kVA and above.
Range open circuit, short circuit, temperature, calibration, test readings, insulation resistance, oil breakdown voltage, functional response to operation of tap changer, pumps, fans; may include but is not limited to
– doble, ductor and polarisation index tests.
Performance criteria
3.1 Tests are carried out in accordance with the prepared work plan.
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6985 version 4
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Element 4
Report repair and overhaul power transformers of 5kVA and above.
Range repair and overhaul report, job sheet, daily diary, log book, test reports and results, plant history, authorisations, ‘as built’ drawings.
Performance criteria
4.1 Reported information is completed and actioned.
4.2 Maintenance information is recorded in the prescribed format and filed within scheduled timeframe.
4.3 Further action required for plant and equipment is identified, recorded, and communicated to appropriate personnel.
Please note
Providers must be accredited by NZQA, or an inter-institutional body with delegated authority for quality assurance, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by NZQA before they can register credits from assessment against unit standards.
Accredited providers and Industry Training Organisations assessing against unit standards must engage with the moderation system that applies to those standards.
Accreditation requirements and an outline of the moderation system that applies to this standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP 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 Electricity Supply Industry Training Organisation info@esito.org.nz
if you wish to suggest changes to the content of this unit standard.
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New Zealand Qualifications Authority 2020