SAQA All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.
SOUTH AFRICAN QUALIFICATIONS AUTHORITY 
REGISTERED UNIT STANDARD THAT HAS PASSED THE END DATE: 

Inspect, test, maintain and commission high voltage transformers 
SAQA US ID UNIT STANDARD TITLE
10277  Inspect, test, maintain and commission high voltage transformers 
ORIGINATOR
SGB Electrical Engineering & Construction 
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY
-  
FIELD SUBFIELD
Field 12 - Physical Planning and Construction Electrical Infrastructure Construction 
ABET BAND UNIT STANDARD TYPE PRE-2009 NQF LEVEL NQF LEVEL CREDITS
Undefined  Regular  Level 4  NQF Level 04  10 
REGISTRATION STATUS REGISTRATION START DATE REGISTRATION END DATE SAQA DECISION NUMBER
Passed the End Date -
Status was "Registered" 		 2002-06-12  2005-06-12  SAQA 0742/02 
LAST DATE FOR ENROLMENT LAST DATE FOR ACHIEVEMENT
2006-06-12   2009-06-12  

In all of the tables in this document, both the pre-2009 NQF Level and the NQF Level is shown. In the text (purpose statements, qualification rules, etc), any references to NQF Levels are to the pre-2009 levels unless specifically stated otherwise.  

This unit standard does not replace any other unit standard and is not replaced by any other unit standard. 

PURPOSE OF THE UNIT STANDARD 
This unit standard is for persons in the Generation; Distribution; Transmission Sector.

The person credited with this unit standard is capable of:
Inspection, testing, maintenance and commissioning of high voltage transformers in order to transform electrical energy in an electrical circuit, in accordance with manufacturers specifications, work site procedures and standards and statutory requirements.

This unit standard will contribute to the full development of the learner within the electrical engineering and construction environment by providing recognition, further mobility and transportability within the field of Physical Planning and Construction. The skills, knowledge and understanding demonstrated within this unit standard are essential for social and economic transformation and upliftment within the electrical engineering and construction environment. 

LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
  • Safety procedures (electrical)
  • Induction to industries
  • Electrical drawings
  • Electrical test instruments
  • Relevant worksite procedures
  • Basic safety procedures related to tools, electricity and cleaning solvents
  • Isolating procedures
  • Dismantling and installation procedures
  • Names and functions of high voltage transformers and their components
  • Carry out insulating oil sampling and voltage breakdown tests
  • Carry out induced voltage tests 
    		•

    UNIT STANDARD RANGE 
    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 oil filled transformers, with off-load or on-load tap changing / diverter switches
  • Relevant drawings
  • Statutory requirements include but are not limited to Occupational Health and Safety Act, SABS 0142, manufacturers specification and worksite procedures.
  • Transformers includes but are not limited to power transformers / Step up and step down transformers / Tappings / Protection / Current transformers / Voltage transformers
  • Transformer equipment includes but is not limited to Bucholz relays, explosion vents, Conservator tank & indicators, temperature probes & indicators, tap changers motor drive, cooling fans and oil pump motors.
  • Inspection report includes but is not limited to verbal and written reports.
  • NOTE: This unit standard does not cover major overhauls of High voltage transformer core or its tap changing mechanism. 
    		•

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    Plan and prepare for inspection, testing, maintenance & commissioning of high voltage Transformers. 
    OUTCOME RANGE 
    Reliable centred maintenance planning periods / schedules, tools, equipment, spares, cleaning material, drawings and documents. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. Planning is arranged, integrated and aligned in terms of resource optimisation. 
    ASSESSMENT CRITERION RANGE 
    Outage schedules, manufacturer's specifications and requirements, other disciplines, control centres, associated equipment, equipment history reports, failure rate, tapping cyclo readings, maintenance programs, plant availability, customer loading requirements.
     

    ASSESSMENT CRITERION 2 
    2. The scope of work and transformer to be inspected, tested, maintained & commissioned is identified according to the job requirement. 
    ASSESSMENT CRITERION RANGE 
    Associated 'check and/or inspection lists', procedures and job required diagnostic tests and maintenance for - transformers with motorised tap changers, temperature probes and indicators, Drawings, nameplate information and documentation.
     

    ASSESSMENT CRITERION 3 
    3. Personnel and equipment resources are sourced for the required work according to the job requirements. 
    ASSESSMENT CRITERION RANGE 
    People, tools, spares, materials, 'inspection sheets', procedure sheets.
     

    ASSESSMENT CRITERION 4 
    4. Equipment test instruments and tools needed for maintenance is selected, inspected and checked for functionality and safety prior to the maintenance task being carried out. 
    ASSESSMENT CRITERION RANGE 
    Test equipment, gas-filling apparatus, and specialised tools.
     

    ASSESSMENT CRITERION 5 
    5. The inspection, diagnostic testing and maintenance requirements are interpreted, and analysed for determining the performance and quality standards required. 
    ASSESSMENT CRITERION RANGE 
    Manufacturer's guidelines, Industry maintenance standards or work site procedures, guidelines & Standards
     

    ASSESSMENT CRITERION 6 
    6. Cleaning material, cleaning equipment and safety equipment are identified and selected to meet job requirements. 
    ASSESSMENT CRITERION RANGE 
    Cleaning solvents, rags, waste material, brushes, scrapers, buckets
     

    SPECIFIC OUTCOME 2 
    Prepare the high voltage transformer for inspection, tests, maintenance and commissioning. 
    OUTCOME RANGE 
    Safety & environmental Regulations - Protective clothing; stored energy; environmental requirements.
    Operating regulations for high voltage systems [ORHVS] - Isolation, Earthing, making safe for work (work permit systems); 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. The high voltage transformer is prepared in accordance with the OHS Act & ORHVS, thus required work permit is received, checked, and signed as per job requirements standards. 
    ASSESSMENT CRITERION RANGE 
    Careful check of the isolations, earthing and safety barricades to ensure the work permit provides a safe work environment.
     

    ASSESSMENT CRITERION 2 
    2. The work party is fully briefed on the high voltage transformer to be worked on in terms of safety regulations. 
    ASSESSMENT CRITERION RANGE 
    Work to be done, re-commissioning process, safe working zone and safety features in place, signed register of all workers, or its approved equivalent. All communication with the work party is clear and unambiguous.
     

    ASSESSMENT CRITERION 3 
    3. Safety measures are available and prepared to protect the environment and personnel as per work site safety requirements. 
    ASSESSMENT CRITERION RANGE 
    Oil spill clean up facilities, protective clothing, oil storage facilities, safe work clearances, storage facilities, safe work area has been identified and demarcated.
     

    ASSESSMENT CRITERION 4 
    4. Additional isolation from other energy sources on the transformer is applied as per maintenance standard requirements. 
    ASSESSMENT CRITERION RANGE 
    Isolating of all 380v auxiliary supply to - tap change motor drive, cooling fan, oil pump temperature probs.
     

    ASSESSMENT CRITERION 5 
    5. All personal protective equipment; tools & equipment and cleaning materials are available on site for use as per job instructions and requirements. 

    ASSESSMENT CRITERION 6 
    6. Obstacles and safety hazards are identified and necessary precautions are taken in accordance with OHSA, ORHVS, local authority; & electrical regulations to ensure work area is/and remains safe for workers. 
    ASSESSMENT CRITERION RANGE 
    Minimum safe working clearances to other energised apparatus or equipment; safe discharges of stored electrical potential (e.g. capacitors)
     

    ASSESSMENT CRITERION 7 
    7. The transformer defect history and operational records are scrutinised and incidents indicating service needs noted for attention during the routine inspections are taken into consideration as per maintenance procedure. 
    ASSESSMENT CRITERION RANGE 
    Serious fault interruptions, malfunction, reported problems, Infra red inspection results, air leaks, oil leaks, faulty fans or pumps.
     

    ASSESSMENT CRITERION 8 
    8. Appropriate drawings/documentation and information is acquired and interpreted as per job and work requirements. 
    ASSESSMENT CRITERION RANGE 
    Main circuit diagrams, AC / DC key diagrams, control circuit diagrams and protection system diagrams
     

    SPECIFIC OUTCOME 3 
    Carry out inspection and tests on High voltage transformers. 
    OUTCOME RANGE 
    History operation reports, visuals, on site tests 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. The inspections carried out according to the maintenance check sheets, identify any damage or defects. 
    ASSESSMENT CRITERION RANGE 
    Oil leaks, excessive gassing, air leaks, overheating / non functional motors or pumps, oil levels in terminal insulators and conservator, damaged porcelain insulators on terminals, corrosion, ware & tare, stress cracks, lack of lubrication, UV damage, paint work faded / metal rusting and seals/ gasket damage.
     

    ASSESSMENT CRITERION 2 
    2. Cooling system is mechanically checked to ensure that it is optimally operational as per manufacturers specifications and work site procedures. 
    ASSESSMENT CRITERION RANGE 
    Oil circulation pumps, cooling fins, cooling fans, temperature probes and indicator instruments
     

    ASSESSMENT CRITERION 3 
    3. Tap change mechanisms are checked for functionality as per manufacturers specifications and work site procedures. 
    ASSESSMENT CRITERION RANGE 
    Tap change drive mechanism, motor, operation cyclo, diverter switches
     

    ASSESSMENT CRITERION 4 
    4. All the diagnostic tests and techniques are carried out as per manufacture requirements, operational standards and the results are analysed in terms of interpreting the maintenance required. 
    ASSESSMENT CRITERION RANGE 
    Dielectric strength tests on transformer oil, induced voltage tests, tests on tap changer and diverter, tap change lock out, contact resistance, protection relay timing tests, trip tests, auxiliary contact tests, Bucholtz relay test, pump/motor run time. Protection alarms and settings on temperature probes and pressure relief valves
     

    ASSESSMENT CRITERION 5 
    5. Oil samples are taken as per manufacturers specification, work site procedures and standards, and sent to laboratory for analysis. 
    ASSESSMENT CRITERION RANGE 
    To determine: - moisture content, internal gasses
     

    ASSESSMENT CRITERION 6 
    6. Conductor / cable connections on terminals are tested according to manufacture requirements and operational standards, and the results analysed for interpreting the maintenance required. 
    ASSESSMENT CRITERION RANGE 
    Contact resistance tests
     

    ASSESSMENT CRITERION 7 
    7. Personal protective equipment is used and site specific procedures are adhered to throughout the process. 
    ASSESSMENT CRITERION RANGE 
    Safety overalls, gloves, goggles, hard hats, safety boots, safety belts/harnesses
     

    ASSESSMENT CRITERION 8 
    8. The results of the inspection & diagnostic tests are analysed and interpreted so as to prepare course of action for maintenance to meet the job requirements. 
    ASSESSMENT CRITERION RANGE 
    Completing worksite check lists, electronic data records, reports, maintenance sheets.
     

    SPECIFIC OUTCOME 4 
    Carry out maintenance on High voltage transformer. 
    OUTCOME RANGE 
    Reliable Centred Maintenance periods or Manufacturers maintenance schedules or other preventative maintenance periods 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. Cleaning is carried out to remove stains and oil leakage spills using specified solvents and materials as per job and safety requirements. 

    ASSESSMENT CRITERION 2 
    2. The minor servicing / maintenance is carried out following manufacturer's procedures and worksite instructions. This may include the disassembly or opening of parts of the equipment and then replacing. 
    ASSESSMENT CRITERION RANGE 
    Insulating oil replacement top-up, oil leaks repaired by replacing gaskets or seals, components, 'repairs to' or 'replacement of' worn parts, replacement of oil temperature cages or float level indicators, replacement of defective seals, cleaning and replacement of breather mechanism components and materials. Repair or replacement of cooling fans or oils circulation pumps.
     

    ASSESSMENT CRITERION 3 
    3. Servicing and maintenance is carried out on the diverter switch mechanism as per manufacturers specifications, work site procedures and standards. 
    ASSESSMENT CRITERION RANGE 
    Insulating oil replacement top-up, oil leaks repaired by replacing gaskets or seals, components, 'repairs to' or 'replacement of' worn parts, replacement at contact buffers, replacement of defective seals, packing, lubricating valves, operation adjustments, contact tip replacement, resister tests and replacement and check / replace flexible internal earth strapping.
     

    ASSESSMENT CRITERION 4 
    4. The re-assembly of all components or parts is carried out in the approved manner provided in the manufacturer's manual and quality maintenance manuals. 
    ASSESSMENT CRITERION RANGE 
    All components being disassembled are assembled in the correct order, with proper fit and secured in the specified way, all tools and cleaning materials are removed from the chambers, insulating medium replaced into transformer to correct level / pressures, permitted moisture parameters and dielectric quality.
     

    ASSESSMENT CRITERION 5 
    5. Ensure that all environmental aspects are taken into consideration as per environmental impact studies / management. 

    ASSESSMENT CRITERION 6 
    6. Safety procedures are adhered to during the whole process. 
    ASSESSMENT CRITERION RANGE 
    Safe Use of: test equipment / Ladders / Scaffolding / platforms, safety gear & discharge earthing.
     

    SPECIFIC OUTCOME 5 
    Perform function tests and pre-service checks. 
    OUTCOME RANGE 
    Operational tests, visual inspections, check sheets 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. Work party is advised of transformer tests and checks about to start as per OHS Act, ORHVS and safe work practices. 
    ASSESSMENT CRITERION RANGE 
    People and tools are all clear of transformer and mechanisms; all communication with the work party is clear and unambiguous.
     

    ASSESSMENT CRITERION 2 
    2. All services and necessary control features are reinstated and approval obtained for function tests according to maintenance procedures. 
    ASSESSMENT CRITERION RANGE 
    Protection circuits, control circuits, mechanism,
     

    ASSESSMENT CRITERION 3 
    3. All the function tests required are completed without malfunction and to worksite standard. 
    ASSESSMENT CRITERION RANGE 
    Induced voltage tests; UV trace tests, flicker test, Tan-delta test, Bucholz operation test, induced pressure test, cooler fail test, oil pump fail test, Induced fault tests, auxiliary contact tests, oil insulation tests, alarm and pressure settings, compressor pump / motor run up time.
     

    ASSESSMENT CRITERION 4 
    4. All equipment worked on is inspected and set for return to service as per maintenance procedures. 
    ASSESSMENT CRITERION RANGE 
    Confirming all equipment and the work party are clear, all operational equipment that has been worked on is now set ready for service. All test equipment is clear.
     

    ASSESSMENT CRITERION 5 
    5. All the maintenance tools and facilities are removed and the Transformer is left in the 'ready-for-service' condition as per maintenance standards and procedures. 
    ASSESSMENT CRITERION RANGE 
    Checking all tools removed, all connections tight, all panels returned, all valves set to 'in-service' position, service, maintenance switch in correct position, Alarms reset, protection relays reset and Oil level indicators checked.
     

    SPECIFIC OUTCOME 6 
    Commission & complete all tasks on Transformer. 
    OUTCOME RANGE 
    Commissioning procedures and pre-energising functional results; Maintenance documentation, inspection sheets, test sheets. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. Post maintenance clean up process is completed according to industry standards, environmental requirements and site specific standards. 
    ASSESSMENT CRITERION RANGE 
    Tools, equipment, oils, gasses, greases, lubricants and solvents.
     

    ASSESSMENT CRITERION 2 
    2. Clearance of the work permit is confirmed as per ORHVS. 
    ASSESSMENT CRITERION RANGE 
    Confirming all members of the work party have signed clearance certificate/workman's registers, Responsible person cleared the work permit and the equipment is returned to service without incident.
     

    ASSESSMENT CRITERION 3 
    3. Commissioning is done as per the commissioning procedure prescribed and ORHVS operating regulations, to minimise impact on system stability and loss of supply to customers. 
    ASSESSMENT CRITERION RANGE 
    The dedicating of the transformer to a specified supply and load, energising in such a way that determines the full supply and loading capability of the transformer.
     

    ASSESSMENT CRITERION 4 
    4. On load Operational tests are done, as per the commissioning procedure prescribed and ORHVS operating regulations, to determine if equipment protection will operate optimally isolating the transformer from the circuit , minimise impact on system stability and loss of supply to customers. 
    ASSESSMENT CRITERION RANGE 
    Fault condition relay operation tests and buz zone operation tests
     

    ASSESSMENT CRITERION 5 
    5. The 'as found' and 'as left' conditions are recorded in the plant history as per maintenance policy and quality standards. 
    ASSESSMENT CRITERION RANGE 
    Analysis and reporting of any defects, correct completion of the plant and defect history, including replacement spares fitted.
     

    ASSESSMENT CRITERION 6 
    6. The equipment condition status is recorded according to site-specific standards. 
    ASSESSMENT CRITERION RANGE 
    Operation counter noted, number of trial operations noted, pressures and auxiliary services quantified.
     

    ASSESSMENT CRITERION 7 
    7. The routine and inspection service records are completed and submitted to meet the worksite requirements. 
    ASSESSMENT CRITERION RANGE 
    Written records and/or electronic data reporting, test reports, inspection reports.
     

    ASSESSMENT CRITERION 8 
    8. Waste material is disposed of according to site specific standards and environmental policies and requirements. 
    ASSESSMENT CRITERION RANGE 
    Gasses, solvents, waste, rags, scrap.
     

    ASSESSMENT CRITERION 9 
    9. Other necessary documentation is completed and submitted to designated personnel. 
    ASSESSMENT CRITERION RANGE 
    Inspection sheets / Test results and reports / Maintenance logs / reports / history; Commissioning test results / reports
     


    UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS 
  • Anyone assessing a learner against this unit standard must be registered as an assessor with the relevant ETQA.
  • Any institution offering learning that will enable achievement of this unit standard must be accredited as a provider through the relevant ETQA by SAQA.
  • Moderation of assessment will be overseen by the relevant ETQA according to the moderation guidelines in the relevant qualification and the agreed ETQA procedures. 
    		•

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
  • A basic understanding and skills in the utilisation of hand tools / Test equipment & measuring tools & specialised tools.
  • A basic understanding & knowledge of: Legislation and applicable regulations
  • A basic knowledge of: safety related standards and procedures
  • A basic knowledge of: Environmental awareness
  • Able to read and interpret basic drawings; diagrams and instructions
  • Able to use a range of cleaning solvents safely and effectively
  • Process and steps involved in the commissioning of Equipment to be used in service in an electrical circuit / system. 
    		•


    Critical Cross-field Outcomes (CCFO): 

    UNIT STANDARD CCFO WORKING 
    Tasks using responsible thinking and decision making (in relation to the use and choice of relevant personal protecting equipment and safety equipment ). 

    UNIT STANDARD CCFO ORGANISING 
    Organise oneself and one`s activities responsibly and effectively (in the ability to follow instructions when working by ones self or in a work team, ensure safe execution of work activities). 

    UNIT STANDARD CCFO COLLECTING 
    Collect, evaluate, organise and critically evaluate information related to ( inspection, testing, maintenance & commissioning of high voltage transformer). 

    UNIT STANDARD CCFO COMMUNICATING 
    Effective use of communication methods when (giving instructions to fellow workers, following of instructions, recording and reporting information). 

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically, showing responsibility towards the environmental and the health of others (inspection, testing, maintenance & commissioning of high voltage transformer to ensuring that all safety and environmental conditions are considered). 

    UNIT STANDARD NOTES 
  • 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.
  • Performance in relation to the elements must comply with current legislation, especially the OSH Act and their subsequent amendments, electricity supply industry codes of practice and documented procedures. A full list of current legislation and industry codes is available from the SETA
  • 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.
  • Performance in relation to the elements must comply with Industry operating regulations for high voltage systems [ORHVS]
  • All work practices shall meet documented industry maintenance standards, including the quality management requirements, and the documentation of activities, events, and decisions.

    SPECIFIED REQUIREMENTS:

    LEGAL REQUIREMENTS:
    SABS 0142
    OHS Act
    Local Authority

    A glossary of terms about the terminology of:
    Switch Gear = Circuit Breaker gear within a circuit
    The following terms and abbreviations relate to this unit standard:
    ORHVS =
    Operating Regulations for High Voltage Systems [extensions to OHSA]
    OHS Act =
    Occupational Health and Safety Act
    HV =
    High voltage

    CONTEXT SPECIFIC
    Specific to a discipline or a industry
  • Manufacturers specifications
  • Work site policies and procedures 
    		•

    QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Core  20420   National Certificate: Electrical Engineering  Level 4  NQF Level 04  Passed the End Date -
    Status was "Registered"     		 2004-02-10  Was EWSETA until Last Date for Achievement 


    PROVIDERS CURRENTLY ACCREDITED TO OFFER THIS UNIT STANDARD: 
    This information shows the current accreditations (i.e. those not past their accreditation end dates), and is the most complete record available to SAQA as of today. Some Primary or Delegated Quality Assurance Functionaries have a lag in their recording systems for provider accreditation, in turn leading to a lag in notifying SAQA of all the providers that they have accredited to offer qualifications and unit standards, as well as any extensions to accreditation end dates. The relevant Primary or Delegated Quality Assurance Functionary should be notified if a record appears to be missing from here.
     
    NONE 


    All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.