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 capacity control systems as used in air-conditioning, refrigeration and ventilation systems 
SAQA US ID UNIT STANDARD TITLE
13480  Demonstrate knowledge of capacity control systems as used in air-conditioning, refrigeration and ventilation systems 
ORIGINATOR
SGB Air-conditioning Refrigeration and Ventilation 
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY
-  
FIELD SUBFIELD
Field 06 - Manufacturing, Engineering and Technology Engineering and Related Design 
ABET BAND UNIT STANDARD TYPE PRE-2009 NQF LEVEL NQF LEVEL CREDITS
Undefined  Regular  Level 5  Level TBA: Pre-2009 was L5  6 
REGISTRATION STATUS REGISTRATION START DATE REGISTRATION END DATE SAQA DECISION NUMBER
Passed the End Date -
Status was "Registered" 		 2001-06-13  2004-06-13  SAQA 0836/01 
LAST DATE FOR ENROLMENT LAST DATE FOR ACHIEVEMENT
2005-06-13   2008-06-13  

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 
Applying suitable control strategies for a variety of refrigeration and air-conditioning, refrigeration and ventilation equipment by using on/off, proportional (P), integral (I) and derivative (D), and fuzzy control action, for determining the settings necessary to have stable and effective control using each method or a combination thereof in suitable applications, and commission systems using each method of control in a variety of applications. 

LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
  • Knowledge of belt drives and gearboxes.
  • Knowledge of all air-conditioning, refrigeration and ventilation equipment of which the capacity can be controlled.
  • Knowledge of control systems. 
    		•

    UNIT STANDARD RANGE 
    Capacity control systems employing on/off, proportional (p), integral (I) and derivative (d) action in any combination, as applied to fans, pumps, compressors, humidifiers, electric and non electric heating banks, motors and any other operating or control element in order to control the capacities of air-conditioning and refrigeration equipment to match the applied load. 

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    List suitable applications for each method of control. 
    OUTCOME RANGE 
    ON/OFF, proportional, integral, derivative and fuzzy control. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. List given is in agreement with control equipment manufacturers' recommended applications or is otherwise proven to be suitable for the cooling/heating equipment. 

    SPECIFIC OUTCOME 2 
    Justify the use of a particular control philosophy in specific applications. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. The justification is done in terms of cost and effective control of the plant to the required specification. 

    ASSESSMENT CRITERION 2 
    2. Control diagrams and sketches are used to support the justification. 

    SPECIFIC OUTCOME 3 
    Determine the value of the settings to be applied to each of the control devices. 
    OUTCOME NOTES 
    Determine the value of the settings to be applied to each of the control devices necessary to maintain the conditions specified, when using each type of capacity control system. 
    OUTCOME RANGE 
    Set point, proportional band, integral timing 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. Values determined are proven to be correct when compared with the values determined or calculated using the equipment manufacturer's method. 

    ASSESSMENT CRITERION 2 
    2. Conditions specified are maintained when the values are applied to an operational system. 

    ASSESSMENT CRITERION 3 
    3. Consequences of incorrect settings are listed and explained. 

    SPECIFIC OUTCOME 4 
    Commission capacity control systems employing each of the methods of control. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    1. Each system commissioned complies with the commissioning requirements of its manufacturer and maintains the specified conditions as the load changes, without hunting or over stability. 


    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 or refrigeration. 

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
    Control terminology as published by companies supplying control instrumentation and systems. The reason why one control system or strategy will not work for all situations. How to recognise the situations most suitable for particular control strategies:
  • Names and functions of control instruments and systems used in air-conditioning, refrigeration and ventilation systems.
  • Purpose of controls.
  • Consequences of selecting and unsuitable control instrument or system. 
    		•


    Critical Cross-field Outcomes (CCFO): 

    UNIT STANDARD CCFO IDENTIFYING 
    Identify and solve problems
  • Identify need for capacity control and select correct method 
    		•

    UNIT STANDARD CCFO COLLECTING 
    Collect, analyse, organise and critically evaluate information
  • Interpretation of requirements and manufacturer`s catalogues 
    		•

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically
  • Application of correct system for various applications 
    		•

    UNIT STANDARD CCFO DEMONSTRATING 
    Demonstrate an understanding of the world as a set of related systems
  • Understanding the need for controlling the capacity of equipment 
    		•

    UNIT STANDARD NOTES 
    Assessment shall only be on commonly applied capacity control systems in South Africa. 

    QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Core  20722   National Diploma: Air Conditioning, Refrigeration and Ventilation  Level 5  Level TBA: Pre-2009 was L5  Passed the End Date -
    Status was "Registered"     		 2004-06-13  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.