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: 

Demonstrate knowledge of single phase transformers 
SAQA US ID UNIT STANDARD TITLE
115244  Demonstrate knowledge of single phase transformers 
ORIGINATOR
SGB Aircraft Maintenance and Overhaul 
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY
-  
FIELD SUBFIELD
Field 06 - Manufacturing, Engineering and Technology Manufacturing and Assembly 
ABET BAND UNIT STANDARD TYPE PRE-2009 NQF LEVEL NQF LEVEL CREDITS
Undefined  Regular  Level 3  NQF Level 03  3 
REGISTRATION STATUS REGISTRATION START DATE REGISTRATION END DATE SAQA DECISION NUMBER
Passed the End Date -
Status was "Reregistered" 		 2018-07-01  2023-06-30  SAQA 06120/18 
LAST DATE FOR ENROLMENT LAST DATE FOR ACHIEVEMENT
2024-06-30   2027-06-30  

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 will be useful to people employed in, or seeking employment in the aerospace industry who are required to maintain aircraft. This unit standard specifies the learning outcomes for instruction in single-phase transformer theory for electricians and related trades.
People credited with this unit standard are able to: demonstrate knowledge of construction and operating principles of transformers; solve problems involving transformers; determine transformer characteristics by measurement; and demonstrate knowledge of transformer applications, and instrument transformers.
They are able to:
  • demonstrate knowledge of construction and operating principles of transformers
  • solve problems involving transformers
  • determine transformer characteristics by measurement
  • demonstrate knowledge of transformer applications 
    		•

    LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
    The credit calculation is based on the assumption that learners are already competent in terms of the following outcomes or areas of learning when starting to learn towards this unit standard:
  • Communications and Mathematical literacy at Level 2, or equivalent competence.
  • In addition learners need to have achieved credit for "Demonstrate knowledge of electrical and electronic components" and "Demonstrate knowledge of electrical safe working practices" or equivalent competence. 
    		•

    UNIT STANDARD RANGE 
    Specific range statements are provided in the body of the unit standard where they apply to particular specific outcomes or assessment criteria. 

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    Demonstrate knowledge of construction and operating principles of transformers. 
    OUTCOME RANGE 
    Transformers include: double-wound transformer, auto-transformer 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Transformer construction is described with the aid of a sketch, and with reference to cores and windings. 

    ASSESSMENT CRITERION 2 
    The transformer operating principle is described with reference to mutual or self-induction and regulation by tap changing. 

    SPECIFIC OUTCOME 2 
    Solve problems involving transformers. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Problems involving primary and secondary turns, voltage, and current are solved for resistive loads. 
    ASSESSMENT CRITERION RANGE 
    IP/IS = NS/NP = VS/VP
     

    ASSESSMENT CRITERION 2 
    Problems involving transformer ratings with resistive loads and negligible losses are solved according to industry practice. 

    ASSESSMENT CRITERION 3 
    The difference between volt-amps and watts is explained with reference to reactive and resistive loads. 

    SPECIFIC OUTCOME 3 
    Determine transformer characteristics by measurement. 
    OUTCOME RANGE 
    Characteristics include: isolating transformer, step-down double-wound transformer, auto transformer 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Voltages and currents are measured and recorded for each transformer, using a resistive load. 

    ASSESSMENT CRITERION 2 
    Volt-amps, power in load, and turns ratio are calculated correctly. 

    ASSESSMENT CRITERION 3 
    Variations between measured and name plate values are explained in terms of supply variations, transformer losses, and measurement error. 

    SPECIFIC OUTCOME 4 
    Demonstrate knowledge of transformer applications. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Double-wound and auto-transformers are compared. 
    ASSESSMENT CRITERION RANGE 
    Comparisons include: physical size, cost and complexity for similar volt-amp, operating voltage ranges; response to load changes, ambient temperature; ease of cooling; operational requirements
     

    ASSESSMENT CRITERION 2 
    Common transformer applications are stated. 
    ASSESSMENT CRITERION RANGE 
    Applications include: double-wound transformer - step up and step down of voltage and current, safety isolation, safety extra-low-voltage source, instrumentation;
    auto-transformer - reduced-voltage motor starters, voltage regulation, variable-voltage supplies
     

    ASSESSMENT CRITERION 3 
    Requirements of current regulations and standards with respect to transformers are stated. 
    ASSESSMENT CRITERION RANGE 
    Requirements include: extra-low voltage circuits, electric toys, medical and dental apparatus, high-voltage discharge lamps, restrictions for auto-transformers;
    for assessment purposes candidates may refer to current regulations and standards
     

    SPECIFIC OUTCOME 5 
    Demonstrate knowledge of instrument transformers. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Voltage transformers are described with reference to typical connections, standard voltage ranges, and burden. 

    ASSESSMENT CRITERION 2 
    Current transformers are described in terms of principle of operation, typical connections, standard current ranges, burden, and safety precautions. 
    ASSESSMENT CRITERION RANGE 
    Current transformer types - bar, wound primary, measurement and protection types.
     

    ASSESSMENT CRITERION 3 
    Reasons for using instrument transformers are described in terms of measurement convenience, and personal and property safety. 
    ASSESSMENT CRITERION RANGE 
    Reasons include: isolation, reduction of voltage and current; remote measurement; metering, indication.
     


    UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS 
    1. Anyone assessing a learner against this unit standard must be registered as an assessor with the relevant ETQA.

    2. Any institution offering learning that will enable achievement of this unit standard must be accredited as a provider through the relevant ETQA by SAQA.

    3. Moderation of assessment will be overseen by the relevant ETQA according to the moderation guidelines and the agreed ETQA procedures. 

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
    Essential embedded knowledge will be assessed through assessment of the specific outcomes in terms of the stipulated assessment criteria. Candidates are unlikely to achieve all the specific outcomes, to the standards described in the assessment criteria, without knowledge of the listed embedded knowledge. This means that for the most part, the possession or lack of the knowledge can be directly inferred from the quality of the candidate's performance. Where direct assessment of knowledge is required, assessment criteria have been included in the body of the unit standard. 

    UNIT STANDARD DEVELOPMENTAL OUTCOME 
    N/A 

    UNIT STANDARD LINKAGES 
    N/A 


    Critical Cross-field Outcomes (CCFO): 

    UNIT STANDARD CCFO IDENTIFYING 
    Identify and solve problems and make decisions using critical and creative thinking.
    Note: The ability of the candidate to identify hazardous conditions, assess and take appropriate action. 

    UNIT STANDARD CCFO WORKING 
    Work effectively with others as members of a team, group, organisation or community.
    Note: The ability and willingness of the candidate to accept and interpret work instructions correctly and to request assistance with making safe in an appropriate manner as a team member. 

    UNIT STANDARD CCFO ORGANISING 
    Organise and manage themselves and their activities responsibly and effectively.
    Note: The preparation for making safe, the candidate must indicate what tools and personnel protective equipment is required and communicate to fellow workers his/her intentions. 

    UNIT STANDARD CCFO COLLECTING 
    Collect, analyse, organise and critically evaluate information.
    Note: The ability of the candidate to reconcile the information from the visual examination and constantly evaluate the changing situation. 

    UNIT STANDARD CCFO COMMUNICATING 
    Communicate effectively, using visual, mathematical and / or language skills in the modes of oral and / or written presentations.
    Note: The appropriate communication with the relevant personnel with regard to the reporting of hazards and sub-standard conditions will indicate his/her proficiency in effective communication 

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically showing responsibility towards the environment and health of others.
    Note: The use of science and technology is not relevant for this unit standard. 

    UNIT STANDARD CCFO DEMONSTRATING 
    Demonstrate an understanding of the world as a set of related systems by recognising that problem-solving contexts do not exist in isolation.
    Note: The ability of the candidate to identify hazard conditions. The effect of non-compliance and deviation from power plant procedures will indicate his/her proficiency in understanding that a specific action or decision taken has more than one effect. 

    UNIT STANDARD ASSESSOR CRITERIA 
    Assessors should keep the following principles in mind when designing and conducting assessments against this unit standard:
  • Focus the assessment activities on gathering evidence in terms of the main outcome expressed in the title to ensure assessment is integrated rather than fragmented. Remember we want to declare the person competent in terms of the title. Where assessment at title level is unmanageable, then focus assessment around each specific outcome, or groups of specific outcomes.
  • Make sure evidence is gathered across the entire range, wherever it applies. Assessment activities should be as close to the real performance as possible, and where simulations or role-plays are used, there should be supporting evidence to show the candidate is able to perform in the real situation.
  • Do not focus the assessment activities on each assessment criterion. Rather make sure the assessment activities focus on outcomes and are sufficient to enable evidence to be gathered around all the assessment criteria.
  • The assessment criteria provide the specifications against which assessment judgements should be made. In most cases, knowledge can be inferred from the quality of the performances, but in other cases, knowledge and understanding will have to be tested through questioning techniques. Where this is required, there will be assessment criteria to specify the standard required.
  • The task of the assessor is to gather sufficient evidence, of the prescribed type and quality, as specified in this unit standard, that the candidate can achieve the outcomes again and again and again. This means assessors will have to judge how many repeat performances are required before they believe the performance is reproducible.
  • All assessments should be conducted in line with the following well documented principles of assessment: appropriateness, fairness, manageability, integration into work or learning, validity, directness, authenticity, sufficiency, systematicity, openness and consistency.

    The following particular issues should be taken into consideration when assessing against this unit standard:
    All tasks are carried out in accordance with enterprise procedures, the enterprise being the organisation carrying out the work. Enterprise procedures referred to in this unit standard are the applicable procedures found in the following:
  • enterprise exposition;
  • manufacturer publications;
  • Government and local body legislation;
  • airworthiness authority requirements. 
    		•

    REREGISTRATION HISTORY 
    As per the SAQA Board decision/s at that time, this unit standard was Reregistered in 2012; 2015. 

    UNIT STANDARD NOTES 
    N/A 

    QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Elective  48861   National Certificate: Aircraft Maintenance and Overhaul  Level 4  Level TBA: Pre-2009 was L4  Passed the End Date -
    Status was "Reregistered"     		 2016-12-31  TETA 


    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.