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: 

Apply an understanding of various systems, system components, the actual and the theoretical refrigeration cycle 
SAQA US ID UNIT STANDARD TITLE
261819  Apply an understanding of various systems, system components, the actual and the theoretical refrigeration cycle 
ORIGINATOR
SGB Air-conditioning Refrigeration and Ventilation 
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  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
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 
Describe and explain how a refrigeration system transfers heat; identify and explain the function of its components and accessories. 

LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
Ability to read and write. A basic knowledge of physics relating to heat and temperature. 

UNIT STANDARD RANGE 
Refrigeration systems:
  • The single stage saturated refrigeration cycle.
  • System cooling air or water and rejecting heat via an air-cooled condenser, a water-cooled condenser and a cooling tower or an evaporative condenser.

    Components including but not limited to:

    The compressor, the expansion valve, evaporators cooling liquid or air, water and air-cooled condensers, the cooling tower and the evaporative condenser, fans, pumps, blower coils and fan-coil units, interconnecting piping, receivers, suction accumulators, vibration eliminators, crankcase heaters, sight glass/moisture indicators, service valves, shut-off valves, safety valves, Schraeder valves, charging valves, fusible plugs, filter-driers, burn-out kits, refrigerant strainers, mufflers, suction-liquid line heat exchangers, oil separators. 
    		•

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    Explain the process taking place in each component. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The processes taking place in the components are explained correctly. 

    ASSESSMENT CRITERION 2 
    The purpose of the condenser water pump, the chilled water pump and the spray water pump in the systems is explained correctly. 

    ASSESSMENT CRITERION 3 
    The phase and temperature of the refrigerant at the inlet and outlet of all components is stated correctly. 

    ASSESSMENT CRITERION 4 
    The temperature of the refrigerant and the water at the inlet and outlet of all the components is stated correctly. 

    SPECIFIC OUTCOME 2 
    Identify and explain the function of components and accessories of a refrigeration system. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The various components and accessories of a refrigeration system are correctly identified and their position in a refrigeration plant is indicated. 

    ASSESSMENT CRITERION 2 
    The purpose of each component and accessory in the refrigeration system is explained. 

    ASSESSMENT CRITERION 3 
    The various types of components and accessories are listed. 

    ASSESSMENT CRITERION 4 
    The different makes and models of components and accessories are identified. 

    SPECIFIC OUTCOME 3 
    Explain the differences in operation between the basic and the actual vapour compression refrigeration cycle. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The differences between the basic and the actual vapour compression refrigeration cycle are explained. 
    ASSESSMENT CRITERION RANGE 
    Sub-cooling, superheating, line pressure drop, non-isentropic compression.
     

    ASSESSMENT CRITERION 2 
    The effects of the actual operating conditions on refrigerant mass flow, COP, power requirements and heat transfer are explained. 

    ASSESSMENT CRITERION 3 
    A flow diagram of the actual vapour compression cycle is sketched and the cycle is drawn on a pressure-enthalpy diagram and compared with the basic cycle. 

    ASSESSMENT CRITERION 4 
    A flow diagram of the cycle and its components when the system is used as a heat pump is sketched and described. 

    ASSESSMENT CRITERION 5 
    Causes and effects of flash gas are explained. 

    SPECIFIC OUTCOME 4 
    Compare and discuss the various types of vapour compression refrigeration systems. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The operation of the various types of actual vapour compression refrigeration systems and the component functions are explained using a block flow diagram showing the various components of such systems. 

    ASSESSMENT CRITERION 2 
    The various systems and typical applications are listed, compared and discussed. 

    ASSESSMENT CRITERION 3 
    Advantages and limitations of the various systems are discussed. 


    UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS 
  • Any person wishing to be assessed against this unit standard may apply to an assessment agency, assessor or provider institution accredited by the relevant ETQA, who may appoint a moderator to be present at the assessment.
  • The assessor must have knowledge and experience of air-conditioning and refrigeration. 
    		•

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
  • The basic processes involved in the vapour compression refrigeration cycle.
  • The various systems used and the role and application of refrigeration in daily life.
  • The function and operation of refrigeration components and accessories.
  • The handling, retrieval and storage of refrigeration system components and accessories.
  • Interpreting manufacturer`s and/or work instructions or company guidelines regarding handling, retrieval and storage of refrigeration system components and accessories. 
    		•

    UNIT STANDARD DEVELOPMENTAL OUTCOME 
    N/A 

    UNIT STANDARD LINKAGES 
    N/A 


    Critical Cross-field Outcomes (CCFO): 

    UNIT STANDARD CCFO IDENTIFYING 
    Identify and solve problems:
  • Identify refrigeration components and accessories. 
    		•

    UNIT STANDARD CCFO WORKING 
    Work effectively with others:
  • Assisting Level 3 Trade hand (Mechanic) by supplying correct accessory. 
    		•

    UNIT STANDARD CCFO ORGANISING 
    Work effectively with others:
  • Assisting Level 3 Trade hand (Mechanic) by supplying correct accessory. 
    		•

    UNIT STANDARD CCFO COMMUNICATING 
    Communicate effectively:
  • By oral or written stores` order for component or accessory. Communicating with Level 3 Trade hand (Mechanic). 
    		•

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically:
  • By understanding the processes involved. 
    		•

    UNIT STANDARD CCFO DEMONSTRATING 
    Demonstrate an understanding of the world as a set of related systems:
  • Be aware of the effect of leakage of refrigerants on the environment. 
    		•

    UNIT STANDARD CCFO CONTRIBUTING 
    Learner and societal development:
  • By learning how a refrigeration system operates. 
    		•

    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  65489   National Certificate: Air-Conditioning, Refrigeration and Ventilation  Level 3  NQF Level 03  Passed the End Date -
    Status was "Reregistered"     		 2023-06-30  MERSETA 


    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.