ELECTRICITY SUPPLY - POWER SYSTEM MAINTENANCE Carry out routine inspection and servicing on high voltage minimum oil circuit breakers

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1 1 of 9 level: 4 credit: 6 planned review date: December 2006 sub-field: purpose: entry information: Electricity Supply People credited with this unit standard are able to: prepare for inspection, testing and servicing on high voltage minimum oil ; make the safe for work; carry out routine inspections and diagnostic tests; carry out servicing; perform function tests and pre-service checks; and complete documentation. Prerequisites: Unit 14287, Use and maintain test instruments used in high voltage electrical industry; Unit 14294, Carry out insulating oil sampling and voltage breakdown tests; Unit 14700, Apply and remove safety measures in an electricity supply environment; Unit 14701, Manage electricity supply work control system; 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: moderation option: Evaluation of documentation and visit by NZQA and industry. A centrally established and directed external moderation system has been set up by the Electricity Supply Industry Training Organisation.

2 2 of 9 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 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.

3 3 of 9 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 diagnostic testing and applying preventative maintenance and replacement repairs where necessary on high voltage minimum oil, and is normally done at electricity supply substations. 6 The following terms and abbreviations relate to this unit standard: CB = Circuit breaker. Elements and Performance Criteria element 1 Prepare for inspection, testing and. 1.1 The scope of work and equipment to be serviced is identified from client requirements. may include but not limited to associated check and/or inspection lists, procedures and client required diagnostic tests and servicing for - minimum oil, with pneumatic, hydraulicspring, motor-spring or solenoid mechanisms.

4 4 of Personnel and equipment are resourced for the required work. may include but not limited to - people, tools, spares, materials, inspection sheets, procedure sheets. 1.3 The inspection, diagnostic testing and servicing requirements are interpreted, and analysed for determining the performance and quality standards required. may include but not limited to - manufacturer s guidelines, client maintenance standards or enterprise guidelines. element 2 Make the safe for work. 2.1 The required access permit, or recognised equivalent, is received, checked, and signed in accordance with the industry and enterprise requirements. includes a careful check of the isolations to ensure the access permit or recognised equivalent provides a safe work environment. 2.2 Additional isolation from other energy sources on the circuit breaker is applied. may include but not limited to - releasing or spragging spring closing energy systems, isolating actuating trip coils and motor drive systems, release or isolation of hydraulic or pneumatic pressure systems.

5 5 of 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 approved equivalent. All communication with the work party is clear and unambiguous. may include but not limited to the ability to resolve any concerns the work party may have over the isolations and the delineation of the safe work area. 2.4 Safety measures are available and prepared to protect the environment and personnel. may include but not limited to - oil spill clean up facilities, protective clothing, storage facilities. element 3 Carry out routine inspections and diagnostic tests. 3.1 The CB defect history and operational records are scrutinised and incidents indicating service needs noted for attention during the routine servicing. may include but not limited to - serious fault interruptions, malfunction, reported problems, thermovision inspection results. 3.2 The inspections carried out identify any damage or defects. may include but not limited to - oil leaks, signs of overheating.

6 6 of The diagnostic tests are carried out and the results analysed for interpreting the servicing required. may include but not limited to - oil breakdown tests, insulation resistance tests, time travel tests, contact resistance, timing tests, minimum operating voltage, trip tests, auxiliary contact tests, oil insulation tests, alarm and pressure settings, compressor pump up time. 3.4 The results of the diagnostic tests are recorded to meet the client requirements. may include but not limited to - completing enterprise check lists, electronic data records, client reports. element 4 Carry out servicing. 4.1 Oil recovery and treatment are completed, consistent with enterprise or client requirements. may include but not limited to storage treatment and re-testing before re-filling the. 4.2 The minor invasive servicing is carried out following enterprise or client procedures. may include but not limited to - insulating oil replacement top-up, repairs to or replacement of worn parts, adjustments, contact tip replacement, cleaning, lubricating, hydraulic control and mechanism serviced.

7 7 of The re-assembly of the circuit breaker is carried out in the approved manner provided by the maker. may include but not limited to - all components being assembled in the correct order, with proper fit and secured in the specified way, oil replaced into circuit breaker to correct level and quality. element 5 Perform function tests and pre-service checks. 5.1 Work party is advised of a trial operation about to start. 5.2 All services and necessary control features are reinstated and approval obtained for function tests. may include but not limited to - air service, control circuits, mechanism, power, indication. 5.3 All the function tests required are completed without malfunction and to standard. may include but not limited to -oil breakdown tests, insulation resistance tests, time travel tests, contact resistance, timing tests, minimum operating voltage, trip tests, auxiliary contact tests, oil insulation tests, alarm and pressure settings, compressor pump up time.

8 8 of All the maintenance tools and facilities are removed and the circuit breaker is left in the ready-for-service condition. may include but not limited to - checking all tools removed, all connections tight, all panels returned, all valves set to in-service position, service, maintenance switch in correct position, CB returned to service. 5.5 All equipment worked on is inspected and set for return to service. may include but 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. 5.6 Return of access permit, or its equivalent, is confirmed. may include but not limited to - confirming all members of the work party have signed off, the equipment is returned to service without incident. element 6 Complete documentation. 6.1 The as found and as left conditions are recorded in the plant history. may include but not limited to - analysis and reporting of any defects, correct completion of the plant and defect history, including replacement spares fitted.

9 9 of The equipment condition status is recorded. may include but not limited to - operation counter noted, number of trial operations noted, pressures and auxiliary services quantified. 6.3 The routine and inspection service records are completed to meet the client requirements. may include but not limited to written records or electronic data reporting. 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