20412 Carry out a Line Patrol on an Electricity Supply Network

Explanatory notes

1This unit standard is intended for, but not restricted to, workplace assessment. The range statements across the unit standard can be applied according to industry specific equipment, procedures, and processes.

2Safety of personnel and plant must be a priority throughout the assessment. If the safety requirements are not met the assessment must stop.

3Performance and work practices in relation to the outcomes and evidence requirements 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 current version of the Safety Manual – Electricity Industry (SM-EI) 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 3240.

4The phrase in accordance with industry requirements is implicit in all outcomes and evidence requirements in this unit standard.

5Industry 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.

6This unit standard covers the visual inspection of electrical supply structures, lines hardware, and conductors and the environment they are in. The more detailed inspections are covered in the unit standards covering condition assessment: Unit 20413, Carry out condition assessments of electricity supply wooden pole structures; Unit 20414, Carry out condition assessments of electricity supply concrete and steel pole structures; Unit 20415, Carry out condition assessments of electricity supply steel tower structures; and Unit 20416, Carry out condition assessments of electricity supply line hardware and conductors.

Outcomes and evidence requirements

Outcome 1

Plan and prepare to carry out a line patrol.

Evidence requirements

1.1Scope of work is identified.

Rangeincludes but is not limited to – inspection requirements, site information, plans, procedures, approvals, public places patrol, aerial patrol, ground patrol.

1.2Landowners are notified and access is agreed.

1.3Communication protocols are established.

1.4Check sheets for inspections are selected.

1.5Network line structure components are described and identified.

Rangeincludes but is not limited to – naming convention for legs, transverse and longitudinal faces, foundation types (grillage, anchor bolt, stub leg), tower components (leg extensions, body extension, superstructure, earth peak, diagonals, horizontals, diaphragm, primary and secondary bracing).

1.6Conductor types are identified and described.

Rangeincludes but is not limited to – Aluminium conductor steel reinforced galvanised core (ACSR/GZ), Aluminium conductor steel reinforced greased core (ACSR/AC), Copper (CU), galvanised extra high strength steel (GEHSS), optical fibre ground wire (OFGW).

1.7Tree species and position in a line span are determined.

1.8Vegetation risk in terms of growth, swing distance or fall distance is assessed and described.

Outcome 2

Inspect access tracks.

Evidence requirements

2.1Type and condition of access tracks are identified.

Rangeincludes but is not limited to – sealed, metalled, un-metalled, unformed.

2.2Access track requirements are identified.

Rangeincludes but is not limited to – two-wheel drive access, four-wheel drive light access, four-wheel drive heavy access, quad bike, dry/wet weather access, foot only access.

2.3Culvert and water table condition is determined.

2.4Bridge types are identified and inspected.

Rangeincludes but is not limited to – single/multiple span, suspension, girder (timber, steel, concrete), culvert, concrete or earth abutment, low-level crossing, footbridge.

Outcome 3

Inspect pole structures.

Evidence requirements

3.1Pole structure is inspected and defects identified.

Rangeincludes but is not limited to – pole verticality, excessive cross-arm tilt or bowing, inadequate foundation compaction or subsidence, step bolts too close to ground level, guy anchor and guy fence problems, earthing and bonding, pole tags (colour).

3.2Concrete pole defects are identified and described.

Rangeincludes but is not limited to – cracks, chips, spalling and reinforcing corrosion.

3.3Steel pole defects are identified and described.

Rangeincludes but is not limited to – corrosion, dents or kinks, deformation, splits.

3.4Wood pole defects are identified and described.

Rangeincludes but is not limited to – decay, splitting, deterioration of repairs, excessive loose sapwood, fire hazards, pole caps.

3.5Tower defects are identified and described.

Rangeincludes but is not limited to – anti-climb frame requirements, steel damage that is of a serious and urgent nature, tower bolt defects, tower distortion from foundation settlement or from construction defects, tower vibration.

3.6Insulators and line hardware defects are identified and described.

Rangeincludes but is not limited to – broken disks, obsolete and mandatory replacement fittings, leaning of suspension insulators, electrical leakage.

3.7Conductor and earth wire defects are identified and described.

Rangeincludes but is not limited to – serious sag and tension differentials including line crossings, broken strands and bulging conductors; loose fittings – dampers, spacers and weights, earthwires sagging below the phase conductors, conductor movement with wind and impact on clearances, conductor movement with temperature change and impact on clearances, conductor to structure electrical clearances, earthwire bonding, foreign objects.

3.8Conductor to ground clearance measurements are taken.

Rangeincludes but is not limited to – minimum clearances for line voltage, measure conductor height.

3.9The separation between buildings and conductors is measured, and the position in the span of the building is identified.

3.10Other structure defects and environmental problems are identified and described.

Rangestructure defects include but are not limited to – signage (including line structure danger, circuit phase identification, aerial identification, navigable waterways), unauthorised attachments to structures, television frequency issues, missing and loose bolts, bent steel, anti-climb frames;

environmental problems include but are not limited to – ponding around the foundation, vegetation at base of structure, subsidence threatening foundations, excavations threatening foundations.

Outcome 4

Inspect vegetation near electrical lines.

Evidence requirements

4.1Vegetation status near lines is identified and described.

Rangeincludes but is not limited to – vegetation encroachment rules, asset owners rights and obligations, minimum separation distances, tree and conductor separation distances, tree fall arcs.

4.2Tree growth patterns that may impact on an existing conductor/tree separation gap are identified and described.

4.3Tree types, growth rates and stability factors are identified and described.

4.4Tree measurements are taken.

Rangeincludes but is not limited to – tele pole, range finder, forest vernier clinometers.

Outcome 5

Report line patrol results.

Evidence requirements

5.1Recorded information is complete, concise, and legible.

5.2Information is recorded in the required format and filed in the required location.

5.3Red or orange tagged wooden poles are reported.

Status information and last date for assessment for superseded versions

This AMAP 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, 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 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.

Consent 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

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