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 an understanding of logic controllers as used in air conditioning, refrigeration and ventilation applications 
SAQA US ID UNIT STANDARD TITLE
116460  Demonstrate an understanding of logic controllers as used in air conditioning, refrigeration and ventilation applications 
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 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 
Learners competent in this unit standard will be able to demonstrate an understanding and explain the use and applications of pre-programmed and programmable logic controllers as used in the control and instrumentation environment in the air conditioning, refrigeration and ventilation industry.
It will also lead to a better understanding of Building Management Systems. 

LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
  • Basic computer literacy.
  • Basic understanding of electricity.
  • Sketch and construct single and three-phase circuits.
  • Understanding the operation of air conditioning, refrigeration or ventilation systems.
  • Understanding control systems as used for air conditioning, refrigeration or ventilation plants.
  • Understanding the sequence op operation for the equipment included in air conditioning, refrigeration or ventilation plants. 
    		•

    UNIT STANDARD RANGE 
    Types of logic controllers.
    Pre-programmed and programmable logic controllers.

    Criteria for selecting logic controllers:
    Pre- programmed or programmable, number of inputs/outputs, cycle time, ease of programming, programming language, cost, maintenance.

    Types Peripherals:
    Input, output, digital, analogue, binary, discrete and intelligent modules, power supplies.
    Processing section, memory module, interface module,

    Terms:
    Pre-programmed controller, programmable logic controller, main controller, processing section, CPU, data, data logging, interface, compatibility, peripheral, digital input/output, analogue input/output, algorithm, voltage free contact, modem, scanning, cycle time, variables, RAM, ROM, EPROM, EEPROM, display unit, user interface, dip switch, modem.
    Input section, processing section, output section,
    Hard wiring, field bus system, twisted pair, screened cable, digital communication bus,
    Interface, programming, modular concept,
    Scanning, access, ladder diagram, function box diagram, instruction list, password,
    "High", "low", "and", "inclusive or", "exclusive or", "not",
    Bit, byte, baud rate, LAN,

    Functions of controllers.
    Indication and/or control of controlled variables such as temperature, humidity, pressure, velocity, etc.
    Automatic or manual switching plant components "on" and "off",
    Controlling speed of motors,
    Alarm functions,
    Fault indication,
    Data logging,
    Energy saving,

    Types of control instruments and sensors:
    Instruments to control temperature, relative humidity, enthalpy, pressure, velocity and liquid level.
    Intelligent sensors, passive sensors.

    Types of outputs.
    Modulating motors, 2-way valve, 3-way valves,
    Relay outputs for AC or DC actuators,
    Semiconductor outputs for DC loads.
    Triac outputs - digital voltage free contacts. 

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    List and discuss the functions and applications of logic controllers. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The terms used to describe the functions of logic controllers are explained. 

    ASSESSMENT CRITERION 2 
    The basic functions and principles of operation of logic controllers are listed and explained. 

    ASSESSMENT CRITERION 3 
    The differences between pre-programmed and programmable logic controllers are listed and explained. 

    ASSESSMENT CRITERION 4 
    The applications of pre-programmed and programmable logic controllers in air conditioning, refrigeration or ventilation systems are listed. 

    ASSESSMENT CRITERION 5 
    The advantages and disadvantages of pre-programmed and programmable logic controllers are listed and discussed. 

    SPECIFIC OUTCOME 2 
    Explain the purpose and application of pre-programmed logic controllers as fitted to air conditioning, refrigeration or ventilation equipment. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The applications of pre-programmed logic controllers are listed and discussed. 

    ASSESSMENT CRITERION 2 
    The advantages and disadvantages of pre-programmed logic controllers are listed and discussed. 

    ASSESSMENT CRITERION 3 
    The possible functions of a pre-programmed controller fitted to an air conditioning, refrigeration or ventilation plant are listed and discussed. 

    ASSESSMENT CRITERION 4 
    The information required to commission a pre-programmed controller is listed and discussed. 

    ASSESSMENT CRITERION 5 
    The methods of programming the controller are listed and explained. 

    SPECIFIC OUTCOME 3 
    Explain the purpose and application of programmable logic controllers as used in air conditioning, refrigeration or ventilation installations. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The applications of programmable logic controllers are listed and discussed. 

    ASSESSMENT CRITERION 2 
    The advantages and disadvantages of programmable logic controllers are listed and discussed. 

    ASSESSMENT CRITERION 3 
    The possible functions of a programmable logic controller fitted to an air conditioning, refrigeration or ventilation plant are listed and discussed. 

    ASSESSMENT CRITERION 4 
    The information required to program a programmable logic controller is listed and discussed. 

    ASSESSMENT CRITERION 5 
    The information required to commission a programmable logic controller is listed and discussed. 

    ASSESSMENT CRITERION 6 
    The methods of programming the controller are listed and explained. 

    SPECIFIC OUTCOME 4 
    Demonstrate an understanding of the input/output peripherals for a programmable logic controller. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The various peripherals are defined and their function explained and discussed. 

    ASSESSMENT CRITERION 2 
    The various input and output peripherals are identified. 

    ASSESSMENT CRITERION 3 
    Hazards associated with the use of logic controllers are recognised and the necessary precautions are taken according to work site procedure. 

    ASSESSMENT CRITERION 4 
    The correct operation of the peripheral devices is verified. 

    ASSESSMENT CRITERION 5 
    The peripherals are correctly removed and replaced according to manufacturer's specification. 

    ASSESSMENT CRITERION 6 
    Personal safety procedures are demonstrated according to activity requirements. 

    SPECIFIC OUTCOME 5 
    Demonstrate an understanding of field devices interfaced to programmable logic controllers. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The correct field device is identified. 

    ASSESSMENT CRITERION 2 
    The field device is correctly connected to the appropriate peripheral. 

    ASSESSMENT CRITERION 3 
    The operation of the field device is verified. 

    ASSESSMENT CRITERION 4 
    Personal safety equipment is selected and used according to activity requirement. 

    SPECIFIC OUTCOME 6 
    Demonstrate an understanding of the processor in a logic controller. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The function of the indicator lights of the processor are explained. 

    ASSESSMENT CRITERION 2 
    The battery of the processor is correctly identified, removed (if necessary) and replaced according to manufacturer's specifications. 

    ASSESSMENT CRITERION 3 
    Faults are correctly identified by utilizing the indicator lights. 

    ASSESSMENT CRITERION 4 
    The processor mode switch is correctly identified and utilized according to the task instructions. 

    ASSESSMENT CRITERION 5 
    Communication status indicators are correctly identified and the status correctly explained. 

    SPECIFIC OUTCOME 7 
    Demonstrate an understanding of the programming terminal (the interface). 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Handheld or programming terminal is correctly connected to the controller. 

    ASSESSMENT CRITERION 2 
    Communication between the programmer and the processor is established. 

    ASSESSMENT CRITERION 3 
    The correct sequence is used to monitor the on-line program that resides in the processor. 

    ASSESSMENT CRITERION 4 
    Instruction mnemonics are explained with reference to filed devices. 

    ASSESSMENT CRITERION 5 
    Programming the logic controller by means of a PC, laptop or hand-held interface is demonstrated. 


    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 logic controllers as used in air-conditioning, refrigeration or ventilation applications. 

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
    Names and functions of logic controllers, components and accessories
    Terms used to describe the functions and operation of logic controllers.
    Understand the basic principles on which logic controllers operate.
    Advantages and disadvantages of use of logic controllers.
    Comparing logic controller operation with hard-wired controls.
    Understanding logic controllers installed on air conditioning, refrigeration or ventilation equipment and being able to enter the program and menu in order to troubleshoot plant directly or via an interface instrument.
    The types of information to be obtained from a system incorporating a logic controller. 

    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 equipment and/or components and dismantling procedure.
  • Interpret installation and operating instructions
  • Select components and measuring instruments. 
    		•

    UNIT STANDARD CCFO ORGANISING 
    Organise and manage myself and my activities
  • Prepare, plan and select information.
  • Select tools 
    		•

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically
  • Identification and selection of components
  • Identification of devices and explaining their purpose. 
    		•

    UNIT STANDARD CCFO CONTRIBUTING 
    Learner and societal development
  • Application can be used in a variety of trades and professions. 
    		•

    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:
    Programming programmable logic controllers is not a requirement of this unit standard. 

    QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Core  48966   Further Education and Training Certificate: Air-conditioning, Refrigeration and Ventilation  Level 4  NQF Level 04  Passed the End Date -
    Status was "Reregistered"     		 2009-03-12  Was MERSETA until Last Date for Achievement 
    Elective  65509   Further Education and Training Certificate: Air-conditioning, Refrigeration and Ventilation  Level 4  NQF Level 04  Passed the End Date -
    Status was "Reregistered"     		 2023-06-30  MERSETA 
    Elective  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.