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SOUTH AFRICAN QUALIFICATIONS AUTHORITY 
REGISTERED UNIT STANDARD THAT HAS PASSED THE END DATE: 

Understand electrical and mechanical engineering principles as applicable to air conditioning and refrigeration systems of domestic appliances 
SAQA US ID UNIT STANDARD TITLE
123452  Understand electrical and mechanical engineering principles as applicable to air conditioning and refrigeration systems of domestic appliances 
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  7 
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
2026-06-30   2029-06-30  

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 is for persons in the electrical engineering field who will be required to maintain and repair refrigerated domestic appliances.

A person credited with this unit standard will be capable of:
  • Explaining the thermodynamic properties of commonly used refrigerants.
  • Demonstrating and explaining the basic concepts of open and closed systems.
  • Applying the basic concepts of fluid mechanics and flow rates.

    This unit standard will contribute to the full development of the learner within the electrical engineering field by providing recognition, further mobility and portability within the field of appliance repair. The skills knowledge and understanding demonstrated within this unit standard are essential for social and economic transformation and contribute to the upliftment and economic growth within the appliance repair environment. 
    		•

    LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
    It is assumed that learners are already competent in the following:
  • Communication at NQF Level 3.
  • Mathematical Literacy at NQF Level 3.
  • A thorough understanding of the operation of air conditioning, refrigeration and ventilation plants.
  • Identify materials, piping, fittings, jointing methods and insulation.
  • Identify and apply fixing methods for piping, ducting and equipment.
  • Demonstrate understanding of fundamentals of electricity and its applications.
  • Identify components, accessories and controls.
  • Handle and place in position equipment used within the domestic air conditioning, refrigeration industries. 
    		•

    UNIT STANDARD RANGE 
    Basic principles of mechanical engineering:
  • Engineering statics and dynamics: Forces, loads, friction, motion, momentum, energy, power, vibrations and balancing.
  • Fluid flow in pipes, ducts and across flat plates: Fluid properties, fluid static's, fluid power, forces developed by flowing fluids.
  • Thermodynamics: Energy, basic concepts, systems, gases, heat transfer.
    > For appliances using not more than 300 grams of refrigerant. 
    		•

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    Name and explain the thermodynamic properties of commonly used refrigerants in domestic appliances. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The phenomenon of energy conversion and the need for high-energy conversion efficiencies is explained in accordance with energy conversion principles. 

    ASSESSMENT CRITERION 2 
    The nature and states of matter are explained in terms of atomic theory. 
    ASSESSMENT CRITERION RANGE 
    Solids, gases, liquids, molecular motion, phase change.
     

    ASSESSMENT CRITERION 3 
    The important thermodynamic properties of a substance and its units of measurement are explained in accordance with thermodynamic principles. 
    ASSESSMENT CRITERION RANGE 
    Mass, volume, density, relative density, specific volume, force, weight, pressure, specific heat, enthalpy, entropy, internal energy.
     

    ASSESSMENT CRITERION 4 
    The various laws of thermodynamics are defined and their importance explained and applied in accordance with thermodynamic principles. 
    ASSESSMENT CRITERION RANGE 
    First, second and third law, laws of Boyle, Charles and Dalton, ideal gas law.
     

    ASSESSMENT CRITERION 5 
    The property changes of a gas undergoing typical thermodynamic processes are calculated using specified formulae and methods. 
    ASSESSMENT CRITERION RANGE 
    Heating, cooling, compression or expansion.
     

    ASSESSMENT CRITERION 6 
    Calculations relating to work, sensible and latent heat transfers and availability in energy are carried out using specified formulae and methods. 

    SPECIFIC OUTCOME 2 
    Explain and apply concepts of open and closed systems as used in domestic appliances. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Open and closed systems are defined and the meaning of steady flow explained in terms of prescribed principles. 

    ASSESSMENT CRITERION 2 
    Calculations involving open and closed systems using steady flow principles are carried out using prescribed methods and formulae. 
    ASSESSMENT CRITERION RANGE 
    Fluids being heated or cooled, heat exchange systems.
     

    ASSESSMENT CRITERION 3 
    The modes of heat transfer are described and explained in terms of in terms of heat transfer principles. 
    ASSESSMENT CRITERION RANGE 
    Convection, conduction, radiation.
     

    ASSESSMENT CRITERION 4 
    The heat transfer rates by combined convection, conduction and radiation through float plates, series flat plates and thick and thin-walled pipes as well as insulated pipes are calculated using prescribed methods and formulae. 

    SPECIFIC OUTCOME 3 
    Explain and apply concepts of fluid mechanics. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The various types and characteristics of fluids are described specifically in terms of location and magnitude. 

    ASSESSMENT CRITERION 2 
    The basic properties of fluids are described in terms of physical and chemical characteristics. 
    ASSESSMENT CRITERION RANGE 
    Compressibility, surface tension, solubility.
     

    ASSESSMENT CRITERION 3 
    Saturation vapour pressure and temperature are described including an explanation of the relationship between them. 

    ASSESSMENT CRITERION 4 
    The basic principles of fluid statics relating to fluid pressure are stated with reference to Pascal's principle. 

    ASSESSMENT CRITERION 5 
    The operation of piezometers and manometers are explained and pressures and pressure differences calculated from observed readings. 
    ASSESSMENT CRITERION RANGE 
    Gas-to-liquid, liquid-to-liquid, vertical and inclined.
     

    ASSESSMENT CRITERION 6 
    Static fluid forces are calculated and their location on surfaces determined from observed readings. 
    ASSESSMENT CRITERION RANGE 
    Location, magnitude.
     

    SPECIFIC OUTCOME 4 
    Explain and apply concepts of flow rates. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The meaning of volume and mass-flow rates are explained and calculated in accordance with volume and mass-flow rates principles. 

    ASSESSMENT CRITERION 2 
    The continuity equation in typical fluid flow applications is explained with reference to fluid flow in pipes and ducts with varying cross section, with or without branches. 

    ASSESSMENT CRITERION 3 
    The Bernoulli equation for flow in an ideal fluid is explained and applied to specified data. 

    ASSESSMENT CRITERION 4 
    The variation in the various head terms for typical fluid flow is described. 

    ASSESSMENT CRITERION 5 
    Equations for fluid power are explained and their use demonstrated with reference to mass flow rates and head, volume flow rate and pressures. 

    ASSESSMENT CRITERION 6 
    The use of fluid machinery equations is described and their use in calculations involving fluid machinery demonstrated in respect of fluid power and head loss and efficiency. 
    ASSESSMENT CRITERION RANGE 
    Application of Bernoulli.
     


    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 provider offering learning that will enable achievement of this unit standard must be accredited as a provider through the relevant ETQA.
  • 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 learner can understand, explain and apply:
  • Names, functions and concepts of basic electrical and mechanical engineering principle applicable to refrigeration systems.
  • Descriptions, characteristics and attributes of Thermodynamic, fluid mechanic and materials properties.
  • Basic understanding of the concepts in thermodynamics, fluid mechanics and strength of materials required to design air conditioning, refrigeration and ventilation systems.
  • Systematic analytical calculation procedures.
  • Rules, principles and laws of Thermodynamics. 
    		•

    UNIT STANDARD DEVELOPMENTAL OUTCOME 
    N/A 

    UNIT STANDARD LINKAGES 
    N/A 


    Critical Cross-field Outcomes (CCFO): 

    UNIT STANDARD CCFO IDENTIFYING 
    Identify and solve problems
  • Identifying and solving problems using basic concepts. 
    		•

    UNIT STANDARD CCFO ORGANISING 
    Organise and manage myself and my activities responsibly and effectively
  • Prepare and plan analytical procedures to solve problems. 
    		•

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically
  • Apply theories and physical laws. 
    		•

    UNIT STANDARD CCFO DEMONSTRATING 
    Demonstrate an understanding of the world as a set of related systems
  • Demonstrate an understanding of the Need for energy and its conservation. Optimum use of energy. 
    		•

    UNIT STANDARD ASSESSOR CRITERIA 
    N/A 

    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
    Core  50371   Further Education and Training Certificate: Domestic Appliance Repair  Level 4  NQF Level 04  Passed the End Date -
    Status was "Reregistered"     		 2023-06-30  EWSETA 


    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.