14329 version 2
28-Jun-16
1 of 8
ELECTRICITY SUPPLY - POWER
SYSTEM MAINTENANCE
Carry out routine inspection and
servicing on distribution power
transformers 33kV to 11kV
level:
4
credit:
8
planned review date:
December 2006
sub-field:
Electricity Supply
purpose:
People credited with this unit standard are able to: prepare
for routine service on distribution power transformers 33kV to
11kV; carry out routine inspections and diagnostic tests;
carry out servicing; record routine inspection and servicing;
and return equipment to service.
entry information:
Prerequisites: Unit 14287, Use and maintain test instruments
used in high voltage electrical industry; Unit 14701, Manage
electricity supply work control system; Unit 14700, Apply and
remove safety measures in an electricity supply environment;
Unit 12296, Apply earths to and remove earths from
electrical conductors, plant and equipment; or demonstrate
equivalent knowledge and skills.
Core electrical theory is essential knowledge underpinning
the performances required by this unit standard.
accreditation option:
Evaluation of documentation and visit by NZQA and industry.
moderation option:
A centrally established and directed external moderation
system has been set up by the Electricity Supply Industry
Training Organisation.
 New Zealand Qualifications Authority 2016
14329 version 2
28-Jun-16
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ELECTRICITY SUPPLY - POWER
SYSTEM MAINTENANCE
Carry out routine inspection and
servicing on distribution power
transformers 33kV to 11kV
special notes:
1
This unit standard can be assessed in a workplace
environment, or in a training or educational environment
if simulated equipment response and examples are
able to be provided, or in a combination of both
environments.
2
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, codes of practice recognised
under that statute, Health and Safety in Employment
Act 1992, Building Act 1991, Resource Management
Act 1991, and their subsequent amendments; Electricity
Regulations 1997, Safety Rules Electricity Industry:
Safety Rules for the New Zealand Electricity
Generation, Transmission and Distribution Industry.
(2000) Wellington: Electricity Engineers’ Association of
NZ (SR-EI), and General Safety Guide Electricity
Industry: Guidance on General Safety in the New
Zealand Electricity Generation, Transmission and
Distribution Industry. (2000) Wellington: Electricity
Engineers’ Association of NZ (GSH-EI); Electricity
Engineers’ Association Codes of Practice; Occupational
Safety and Health Approved Codes of Practice; New
Zealand Electrical Codes of Practice (NZECP). A full
list of current legislation and industry codes is available
from:
Electricity Supply Industry Training Organisation
PO Box 1245
HAMILTON.
3
Reference to terms, procedures, and specifications in
this unit standard may be taken as including
documented procedures and specifications relevant to
the workplace in which assessment is carried out.
 New Zealand Qualifications Authority 2016
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ELECTRICITY SUPPLY - POWER
SYSTEM MAINTENANCE
Carry out routine inspection and
servicing on distribution power
transformers 33kV to 11kV
4
All work practices shall meet documented enterprise
maintenance standards, including the quality
management requirements, and the documentation of
activities, events, and decisions.
5
The range of this unit standard is limited to carrying out
routine, preventative maintenance inspection and
servicing on distribution power transformers 11kV to
33kV normally applied at electricity supply Substations.
6
The following terms and abbreviations related to this
unit standard.
IEC
=
International Electrotechnical
Commission
DGA
=
Dissolved gas analysis.
Elements and Performance Criteria
element 1
Prepare for routine service on distribution power transformers 33kV to 11kV.
performance criteria
1.1
The scope of work and equipment is identified and servicing procedures
selected.
Range:
1.2
may include but not limited to associated client or enterprise
‘check and/or inspection lists’ and procedures for - power
transformers, voltage regulators, reactors.
The anticipated replacement spares are made available.
Range:
may include but not limited to completion of the necessary
documentations where required to uplift client held spares.
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ELECTRICITY SUPPLY - POWER
SYSTEM MAINTENANCE
Carry out routine inspection and
servicing on distribution power
transformers 33kV to 11kV
1.3
The equipment is released from operational use.
Range:
1.4
The defect history and plant history records are scrutinised for indications of
servicing needs.
Range:
1.5
may include but not limited to - a careful check of the isolations to
ensure the access permit or recognised equivalent provides a safe
work environment, check space needed to carry out work safely,
confined spaces permits.
All safety measures are in place to eliminate, minimise or control hazards in the
permit area.
Range:
1.7
may include but not limited to - known defects, operator reports,
client special service requests, oil analysis, dissolved gas
analysis, thermography tests.
The required access permit, or recognised equivalent, is received, checked and
signed, in accordance with the industry and enterprise requirements.
Range:
1.6
may include but not limited to the correct and timely completion of
all the prescribed equipment release requests.
includes inspection of the safe working zone to ensure the safe
work area has been correctly delineated and provides a safe work
environment.
The work party is fully briefed on the equipment to be worked on, work to be
done, safe working zone and safety features in place, and has signed the
access permit or its recognised equivalent. All communication with the work
party is clear and unambiguous.
Range:
includes the ability to resolve any concerns the work party may
have over the isolations and the delineation of the safe work area.
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ELECTRICITY SUPPLY - POWER
SYSTEM MAINTENANCE
Carry out routine inspection and
servicing on distribution power
transformers 33kV to 11kV
element 2
Carry out routine inspections and diagnostic tests.
performance criteria
2.1
Personnel and equipment are resourced for the required work.
Range:
2.2
Inspection and diagnostic tests are completed in accordance with the selected
procedures.
Range:
2.3
may include but not limited to - people, tools, spares, materials,
‘inspection sheets’, procedure sheets, diagnostic test equipment.
may include but not limited to applying tests across the following in
accordance with IEC 76 or quoted standards. The deviation to be
less than what the client has prescribed;
windings - resistance of windings, tap changer, surge arrestors,
insulation resistance, thermal auto-protection, thermal comparison
between units, thermal alarms;
bushings - tap insulation resistance, insulation resistance;
cooling system - all pump operating smoothly, controls and
indication, fans tested, alarms and settings;
protection - Buchholz relay indications, pressure relief valve
indication, oil flow indication, oil sampling for DGA and moisture
and power factor analysis, tap change number operations
checked;
tank - inspection for oil leaks, plinth footings.
All diagnostic test results are interpreted and analysed for compliance with
standard.
Range:
may include but not limited to results that are outside of client,
manufacturer or international standards and where corrective
action is required. Interpretation of results may include
recommendations for servicing action.
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ELECTRICITY SUPPLY - POWER
SYSTEM MAINTENANCE
Carry out routine inspection and
servicing on distribution power
transformers 33kV to 11kV
element 3
Carry out servicing.
performance criteria
3.1
All required servicing carried out is consistent with guidelines and procedures.
Range:
3.2
may include but not limited to the following activities - on line oil
filters checked, cleaning ceramic bushings, Buchholz relay
operation checks, replacement of oil pump bearings or unit, fan
motor repairs, remove blockages in oil system, check seismic
constraints are secure, oil treatment and re-testing, tap changer
inspection and oil change.
All equipment is reinstated on the transformers.
Range:
may include but not limited to - all restored equipment is fitted
correctly in the proper order and secured ready for service,
connections tight and electrically correct, oil levels are correct to
level indication.
element 4
Record routine inspection and servicing.
performance criteria
4.1
The ‘as left’ conditions are recorded in the plant history or defect history.
Range:
may include but not limited to - analysis and reporting of any
defects, correct completion of the plant history, including items
replaced.
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ELECTRICITY SUPPLY - POWER
SYSTEM MAINTENANCE
Carry out routine inspection and
servicing on distribution power
transformers 33kV to 11kV
4.2
The equipment condition status is recorded in accordance with client
requirements.
Range:
may include but not limited to - cyclo recorder, number of trial
operations noted, pressures and auxiliary service quantified,
replacement spares fitted.
element 5
Return equipment to service.
performance criteria
5.1
Work party are withdrawn and warned the equipment is no longer safe to work
on.
Range:
5.2
All tools and recipient-applied safety measures are removed in accordance with
client requirements.
Range:
5.3
includes all access devices, for example, work platforms, scaffold,
barriers and notices, ‘cherry pickers’.
All equipment worked on is inspected and set for return to service.
Range:
5.4
includes notification to the work party to regard the equipment as
live when they have signed off.
includes - confirming all equipment and the work party are clear,
all operational equipment which has been worked on is now set
ready for service.
Return of access permit, or its approved equivalent, is confirmed.
Range:
includes - confirming all members of the work party have signed
off, the equipment is returned to service without incident.
 New Zealand Qualifications Authority 2016
14329 version 2
28-Jun-16
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ELECTRICITY SUPPLY - POWER
SYSTEM MAINTENANCE
Carry out routine inspection and
servicing on distribution power
transformers 33kV to 11kV
Comments on this unit standard
Please contact the Electricity Supply Industry Training Organisation ceo@esito.org.nz if
you wish to suggest changes to the content of this unit standard.
Please Note
Providers must be accredited by the Qualifications Authority or a delegated interinstitutional body before they can register credits from assessment against unit standards
or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by the Qualifications Authority 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 providers wishing to
develop education and training programmes, such as minimum qualifications for tutors and
assessors, and special resource requirements.
This unit standard is covered by AMAP 0120 which can be accessed at
http://www.nzqa.govt.nz/site/framework/search.html.
 New Zealand Qualifications Authority 2016