14335 version 4
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Service and repair high voltage disconnectors, earth switches and other
bus structure equipment
Level
3
Credits
6
Purpose
People credited with this unit standard are able, for high voltage
disconnectors, earth switches and other bus structure connected equipment,
to: prepare for routine service; carry out routine inspection and prescribed
diagnostic tests; service and repair or replace defective worn parts; carry out
trial operational checks; and return equipment to service.
Subfield
Electricity Supply
Domain
Electricity Supply - Power System Maintenance
Status
Registered
Status date
27 April 1998
Date version published
20 June 2008
Planned review date
31 December 2009
Entry information
Prerequisites: Unit 14287, Use and maintain test
instruments used within the high voltage electrical
industry; 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
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.
 New Zealand Qualifications Authority 2016
14335 version 4
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Special notes
1
This unit standard can be assessed against 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 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,
Hamilton.
3
The phrase in accordance with industry requirements is implicit in all elements and
performance criteria in this unit standard.
4
‘Industry requirements’ include all industry and workplace documented policies,
procedures, specifications, and business and quality management relevant to the
workplace where assessment is carried out.
5
All work practices shall meet documented enterprise maintenance standards,
including the quality management requirements, and the documentation of activities,
events, and decisions.
6
The range of this unit standard is limited to the service and repair of high voltage
disconnectors, earth switches, and other bus connected equipment normally installed
at electricity supply substations. It does not include high voltage power or instrument
transformers or high voltage circuit breakers, which are covered by separate unit
standards.
 New Zealand Qualifications Authority 2016
14335 version 4
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Elements and performance criteria
Element 1
Prepare for routine service of high voltage disconnectors, earth switches, and other bus
connected equipment.
Performance criteria
1.1
The scope of work and equipment are identified and servicing procedures
selected.
Range
1.2
The special tools and test equipment are selected for use with equipment to be
worked on.
Range
1.3
may include but is not limited to – routine inspection, operation
reports of operating difficulties, thermovision inspection reports.
The anticipated replacement spares are made available.
Range
1.5
may include but is not limited to maker’s tools for the following
equipment – disconnectors and associated mechanism boxes, line
traps, injection couplings, bus clamps, earth switches;
disconnector types may be – pantograph, vertical break or side
rotating;
disconnector contacts may be – beaver tail, wedge type, high
pressure types, single side break, double side breaks, centre side
break or rocking post types;
warning signs, equipment labels, flexible seismic joints.
All defect records and significant reports from routine inspections are analysed
for identifying maintenance requirements.
Range
1.4
may include but is not limited to – system and control circuit wiring
diagrams, client maintenance standards, manufacturer’s manuals
for disconnectors and associated mechanism boxes, line traps,
injection couplings, bus clamps, earth switches;
disconnector types may be – pantograph, vertical break or side
rotating;
disconnector contacts may be – beaver tail, wedge type, high
pressure types, single side break, double side breaks, centre side
break or rocking post types;
warning signs, equipment labels, flexible seismic joints.
includes the completion of the necessary documentations, where
required, to uplift client held spares.
The equipment is released from operational use.
Range
includes the correct and timely completion of all the prescribed
equipment release requests.
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14335 version 4
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1.6
Maintenance documentation is prepared with known service history available.
Range
may include but is not limited to – any information concerning
known previous problems or defects, maintenance procedures
sheets, check lists.
Element 2
Carry out routine inspections and prescribed diagnostic tests.
Performance criteria
2.1
The equipment is removed from operational service and the equipment being
worked on has been made safe for the work.
Range
2.2
The appropriate work control system approval is provided for the work party.
Range
2.3
may include but is not limited to checks required by client’s
standards and manufacturer’s manuals, and may include the
following test checks – contact resistance, all poles correctly
synchronised, inspection of contacts, inspection of arcing horns,
inspect mechanism for oil leaks, trial operations timed, torque up
rods and bell cranks, motor current tests, smooth operation,
contact tension, operating mechanism checked for mechanical
stiffness, looseness or other wear related problems.
The test values are noted on the service documentation.
Range
2.5
includes all the work party being briefed on equipment being
worked on, work to be done, and safe working area.
The inspection and diagnostic checks are carried out.
Range
2.4
may include but is not limited to checks by the recipient that the
correct isolations have been carried out and any secondary deenergisation required has been identified.
includes – recording the results to meet the client’s requirements),
comparing results with those previously obtained, commenting on
any unsatisfactory results, notification to the client regarding
problems.
The components needing adjustment or replacement are documented.
Range
may include recording any adjustments or replacements of
components in a manner consistent with the client’s standards.
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Element 3
Service and repair or replace defective or worn parts.
Performance criteria
3.1
The defective or out of adjustment components are identified, and replaced or
re-adjusted to meet client requirements.
Range
3.2
Checks are made for correct fit, and replacements are documented.
Range
3.3
may include but is not limited to – checking that the part number
corresponds with the manufacturer’s part number, that any moving
parts move freely with no significant resistance or evidence of
binding.
Equipment is re-assembled following manufacturers guidelines. All components
are fitted in their correct order and fastened as required by procedure.
Range
3.4
may include but is not limited to using the manufacturer’s
description and identifier where available, and the clients identifier
(eg stock item number) if available. May include – contact repairs,
pole travel adjustment, application of correct lubrication,
mechanism operation adjusted, main connections secured,
corrosion repairs.
may include but is not limited to the ability to assimilate and follow
the information in the manufacturer’s manual (where available).
Equipment is made ready for testing.
Range
may include but is not limited to confirmation that the correct
equipment, set-up, and test methods are being used for testing.
Element 4
Carry out trial operational checks.
Performance criteria
4.1
Approval is obtained to carry out trial operational checks.
Range
4.2
may include but is not limited to compliance with the client’s
requirements or rules to obtain an approval to carry out
operational checks.
Work party is made aware of tests and cleared off the equipment before the
testing commences.
Range
includes ensuring that the work party are informed of, and their
understanding verified of, the nature and extent of the tests, and
what is required of them during the tests.
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4.3
The operational checks are completed and are within the design parameters.
Element 5
Return equipment to service.
Performance criteria
5.1
Work party is 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
may include but is not limited to all access devices; for example,
work platforms, scaffold, ‘cherry pickers’.
All equipment worked on is inspected and set for return to service.
Range
5.4
may include but is not limited to notification to the work party to
regard the equipment as live when they have signed off.
may include but is not limited to – 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
may include but is not limited to – confirming all members of the
work party have signed off, the equipment is returned to service
without incident.
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.
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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.
 New Zealand Qualifications Authority 2016