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

Identify and commission modulating control systems as used in air conditioning and refrigeration systems 
SAQA US ID UNIT STANDARD TITLE
116465  Identify and commission modulating control systems as used in air conditioning and refrigeration systems 
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  6 
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 
To enable the learner to:
  • Identify, commission and troubleshoot modulating controls and control systems used in air conditioning and refrigeration systems,
  • Describe their purpose, function and operation, and
  • Connect and commission modulating control systems. 
    		•

    LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
  • Use of hand tools
  • Identify electrical cables.
  • Sketch and construct electrical circuits for air conditioning and refrigeration plants.
  • Identify and set ON-OFF control devices used in air conditioning and refrigeration systems.
  • Explain the operation of commonly applied air conditioning and refrigeration systems. 
    		•

    UNIT STANDARD RANGE 
    Types of electronic modulating control systems:
    Floating control, proportional, proportional and integral (PI), and proportional integral and derivative control (PID), fuzzy controls.
    Terms:
    Proportional action, offset, throttling range, differential, sensitivity, dead zone or dead band, corrective action, lag, direct acting, reverse acting, integral action, derivative action, fuzzy logic, plant management system.
    Types of sensors:
    Electronic type sensor for temperature, enthalpy, relative humidity, pressure, velocity and level.
    NTC and PTC sensors, active and passive sensors.
    Categories of control devices:
    Operational controls, safety controls and efficiency controls.
    Commonly controlled variables.
    Air temperature, humidity, enthalpy, pressure and velocity.
    Liquid temperature, pressure, velocity and level.
    Refrigerant pressures and temperatures.
    Superheat, sub-cooling and temperature differences.
    Safety controls:
    Overheating stats, humidity stats, pressure switches, flow switches, interlocks.
    Types of controllers:
    Electronic, pre-programmed and programmable.
    Types of actuators:
    Relays, contactors, valve actuators and damper motors.
    Types of interface instruments:
    Hand-held and PCs.
    Commonly applied air conditioning and refrigeration systems:
  • Cooling only,
  • Heating only,
  • Cooling and heating,
  • Cooling, heating, humidification and dehumidification.
  • Air pressure, temperature and velocity controls,
  • VAV systems,
  • Defrost control systems for freezer rooms. 
    		•

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    List and discuss the types of modulating control systems and explain their function and operation. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    A modulating control system is defined and its main parts are named. 

    ASSESSMENT CRITERION 2 
    The terms used to describe the function and operation of modulating control systems are listed and discussed. 

    ASSESSMENT CRITERION 3 
    The types of modulating control systems are stated and their function and operation is explained. 

    ASSESSMENT CRITERION 4 
    The variables that are commonly controlled by electronic control systems in air conditioning and/or refrigeration systems are listed. 

    ASSESSMENT CRITERION 5 
    The types of sensors used are listed, compared and contrasted. 

    SPECIFIC OUTCOME 2 
    State and describe the three categories of control devices used on air conditioning and refrigeration systems. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The three categories of control devices used on air conditioning and refrigeration systems are stated. 

    ASSESSMENT CRITERION 2 
    The purpose of the different categories of control devices is stated. 

    ASSESSMENT CRITERION 3 
    Examples of these categories of devices are listed and discussed. 

    SPECIFIC OUTCOME 3 
    List the commonly used types of sensors and describe their application. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The types of sensors used are listed and described. 

    ASSESSMENT CRITERION 2 
    Typical applications of these measuring elements and sensors are named. 

    ASSESSMENT CRITERION 3 
    The advantages and disadvantages of the different types are listed. 

    ASSESSMENT CRITERION 4 
    The application of the different types are listed and discussed. 

    SPECIFIC OUTCOME 4 
    Connect and commission modulating control devices. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The control devices are correctly connected. 

    ASSESSMENT CRITERION 2 
    The control devices are correctly set to stated parameters. 

    ASSESSMENT CRITERION 3 
    Operation of the control devices is checked. 

    ASSESSMENT CRITERION 4 
    Possible malfunctions are listed and discussed 

    SPECIFIC OUTCOME 5 
    Commission modulating control systems. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Correct commissioning information is obtained and interpreted. 

    ASSESSMENT CRITERION 2 
    Control system to be commissioned is identified. 

    ASSESSMENT CRITERION 3 
    Control system is checked for safe and correct operation. 

    ASSESSMENT CRITERION 4 
    All set points are checked and found to agree with commissioning instructions. 

    ASSESSMENT CRITERION 5 
    All systems are found to be operating correctly as per instructions. 

    ASSESSMENT CRITERION 6 
    Commissioning report is completed as per work site instructions. 

    SPECIFIC OUTCOME 6 
    Check system operating parameters. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The correct hand-held instruments are selected. 

    ASSESSMENT CRITERION 2 
    The system is accessed correctly. 

    ASSESSMENT CRITERION 3 
    The operating parameters are all determined and interpreted correctly. 

    ASSESSMENT CRITERION 4 
    Changes to conform to stated standards are made. 

    ASSESSMENT CRITERION 5 
    The system is left in operating condition. 

    ASSESSMENT CRITERION 6 
    No damage occurred to equipment or instrumentation. 


    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 electronic control systems as used in air-conditioning or refrigeration. 

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
    The identification, purpose, function, operation and commissioning of modulating control systems.
    The skill to commission electronic control instruments and systems to perform in accordance with stated parameters.
    The skill to interrogate electronic control systems by means of a hand-held interface or a PC. 

    UNIT STANDARD DEVELOPMENTAL OUTCOME 
    N/A 

    UNIT STANDARD LINKAGES 
    N/A 


    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 
    Supplementary information:

    Only knowledge of the purpose and operation of the controls is required.
    The learner is not required to select the controls or control systems.
    Commissioning will be in accordance with instructions and stated control parameters. 

    QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Elective  48963   National Certificate: Air-Conditioning, Refrigeration and Ventilation  Level 3  NQF Level 03  Passed the End Date -
    Status was "Reregistered"     		 2009-03-12  Was MERSETA until Last Date for Achievement 
    Elective  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.