Unit of Competency Mapping – Information for Teachers/Assessors – Information for Learners

UEERA0068 Mapping and Delivery Guide
Repair and service self-contained carbon dioxide refrigeration and heat pump systems

Version 1.0
Issue Date: May 2024


Qualification -
Unit of Competency UEERA0068 - Repair and service self-contained carbon dioxide refrigeration and heat pump systems
Description
Employability Skills
Learning Outcomes and Application This unit involves the skills and knowledge required to repair and service self-contained carbon dioxide (CO²) refrigeration and heat pump system.It includes specialised procedures for servicing and repairing of self-contained refrigeration and heat pump equipment using CO² as a refrigerant. It also includes applying safe working practices and refrigeration principles that apply to CO²; following service manuals; testing, locating and rectifying faults and defective components; and completing the necessary service documentation.The skills and knowledgein this unit will be applied by refrigeration and air conditioning technicians during the service and repair of self-contained refrigeration systems using CO² refrigerant.The skills and knowledge described in this unit require a licence or permit to practice in the workplace where work is carried out on electrical installations which are designed to operate at voltages greater than 50 volt (V) alternating current (a.c.) or 120 V direct current (d.c).Competency development activities in this unit are subject to regulations directly related to licensing. Where a licence or permit to practice is not held, skills and knowledge described in this unit require a relevant contract of training, such as an Australian Apprenticeship. Additional and/or other conditions may apply in some jurisdictions subject to regulations related to refrigeration, air conditioning or electrical work. Practice in the workplace and during training is also subject to work health and safety (WHS)/occupational health and safety (OHS) regulations. Permits may also be required for some work environments, such as confined spaces, working aloft, near live electrical apparatus and site rehabilitation.
Duration and Setting X weeks, nominally xx hours, delivered in a classroom/online/blended learning setting.

Assessors must hold credentials specified within the Standards for Registered Training Organisations current at the time of assessment.

Assessment must satisfy the Principles of Assessment and Rules of Evidence and all regulatory requirements included within the Standards for Registered Training Organisations current at the time of assessment.

Assessment must occur in suitable workplace operational situations where it is appropriate to do so; where this is not appropriate, assessment must occur in suitable simulated workplace operational situations that replicate workplace conditions.

Assessment processes and techniques must be appropriate to the language, literacy and numeracy requirements of the work being performed and the needs of the candidate.

Resources for assessment must include access to:

a range of relevant exercises, case studies and/or other simulations

relevant and appropriate materials, tools, facilities, equipment and personal protective equipment (PPE) currently used in industry

resources that reflect current industry practices in relation to servicing, repairing and determining the operating conditions of CO² vapour compression and liquid recirculation/cascade systems

applicable documentation, including workplace procedures, equipment specifications, regulations, codes of practice and operation manuals.
Prerequisites/co-requisites
Competency Field Refrigeration and air-conditioning
Development and validation strategy and guide for assessors and learners Student Learning Resources Handouts
Activities 		Slides
PPT 		Assessment 1 Assessment 2 Assessment 3 Assessment 4
Elements of Competency Performance Criteria              
Element: Prepare to service self-contained CO² refrigeration and heat pump system
  • WHS/OHS hazards, risk control methods, relevant standards, codes and legislation are obtained and applied
       
Element: Safety hazards not previously identified are reported, risk assessed and advice on risk control measures sought from work supervisor
       
Element: Nature of work is obtained from documentation or from work supervisor to determine the scope of work to be undertaken
       
Element: Advice is sought from work supervisor to ensure the work is coordinated effectively with others
       
Element: Sources of materials required for the refrigeration work are accessed in accordance with workplace and procedures
       
Element: Tools, equipment and testing devices needed to carry out refrigeration work are obtained and checked for correct operation and safety
       
Element: Service and repair self-contained CO² refrigeration and heat pump system
  • Measuring system operating parameters are conducted in accordance with WHS/OHS requirements and workplace safety procedures
       
Element: Refrigeration inspection and checks are carried out to ensure the system or component parts are isolated in accordance with WHS/OHS requirements and workplace procedures
       
Element: Refrigerant is removed from system safely in accordance with regulatory requirements, industry standards and practices
       
Element: Precautions are taken to prevent damage to components while pressure testing the refrigeration and heat pump system
       
Element: Pressure testing is conducted at a pressure compatible with CO² and in accordance with industry standards and practices
       
Element: Refrigerant leaks are located and rectified using testing methods appropriate to the system and in accordance with industry standards and practices
       
Element: Refrigeration and heat pump system is evacuated to the required level and cleaned of all moisture and other contaminants in accordance with industry standards and practices
       
Element: Refrigeration and heat pump system is charged safely with refrigerant grade CO² and compatible lubricants in accordance with industry standards and practices
       
Element: Actual and specified range of operating conditions are determined from measured and calculated values as they apply to CO² vapour compression systems in accordance with workplace procedures and industry standards
       
Element: Unplanned situations are dealt with safely and in accordance with workplace procedures and approval of authorised person/s in a manner that minimises risk to personnel and equipment
       
Element: Operating conditions are determined without damage to apparatus, circuits, the surrounding environment or services using sustainable energy practices
       
Element: Complete and report servicing and repair of self-contained CO² refrigeration and heat pump system work activities
  • Worksite is cleaned and made safe in accordance with workplace procedures
       
Element: Contaminated refrigerant and lubricant are dealt with in accordance with legislative/regulatory and industry standard requirements
       
Element: Operation conditions are documented and include identification of any parameter that is not within the specified range for the system
       
Element: Work supervisor is notified of the completion of work in accordance with workplace procedures
       


Evidence Required

List the assessment methods to be used and the context and resources required for assessment. Copy and paste the relevant sections from the evidence guide below and then re-write these in plain English.

Evidence required to demonstrate competence in this unit must be relevant to and satisfy all of the requirements of the elements, performance criteria and range of conditions on at least two separate occasions and include:

applying relevant legislation, industry standards and practices

applying relevant work health and safety (WHS)/occupational health and safety (WHS/OHS) requirements and workplace procedures and practices, including using risk control measures

applying sustainable energy principles and practices

dealing with unplanned events/situations in accordance with workplace procedures in a manner that minimises risk to personnel and equipment

discharging/charging refrigerant/lubricants and pressure testing the system without damage to components

documenting operating conditions correctly

identifying the conditions of the carbon dioxide (CO²) refrigerant at various locations in the vapour compression system in a trans-critical and sub-critical state

locating and rectifying leaks

pressure testing, evacuating, charging/discharging refrigerant/lubricants and determining the operating conditions of CO² vapour compression systems

recording measurements

selecting and using appropriate measuring devices correctly

using calculation methods accurately.

Evidence required to demonstrate competence in this unit must be relevant to and satisfy all of the requirements of the elements, performance criteria and range of conditions and include knowledge of:

CO² refrigeration compressors and lubricants, including:

types, construction and their applications

types of compatible compressor oil (Polyolester (POE) and Polyaphalefin (PAO))

safe handling of lubricants for CO² applications using safety data sheets (SDS)/material safety data sheets (MSDS)

cylinder regulators

moisture problems with CO² systems

refrigerant CO² cylinders and regulators

refrigerant conditions

refrigeration principles

relevant industry standards, codes and practices

relevant job safety assessments or risk mitigation processes, including hazards associated with CO²

relevant manufacturer specifications

relevant WHS/OHS legislated requirements

relevant workplace documentation, including service manuals and service documentation

relevant workplace policies and procedures

self-contained systems employing CO² refrigerant at trans-critical condition, including:

basic operation

domestic refrigerators and freezers

heat pumps

water heaters

refrigerated cabinets

systems and major components

typical applications

service gauges

service procedures

CO² refrigerant, including:

benefits of using CO² as a refrigerant

thermophysical properties

servicing tools, equipment and safe working procedures, including:

cylinder regulators

moisture problems with CO² systems

refrigerant CO² cylinders and regulators

refrigerant conditions

service gauges

service procedures

system standing pressure as a result of power loss

system components, construction and operation, including:

capillary tubes and accurators

CO² evaporator design features

CO² sub-cooler design features

electronic expansion valves

liquid-suction heat exchangers

pressure relief devices

refrigerant flow controls

system standing pressure as a result of power loss.

trans-critical CO² refrigeration and heat pump systems.

Submission Requirements

List each assessment task's title, type (eg project, observation/demonstration, essay, assignment, checklist) and due date here

Assessment task 1: [title]      Due date:

(add new lines for each of the assessment tasks)

Assessment Tasks

Copy and paste from the following data to produce each assessment task. Write these in plain English and spell out how, when and where the task is to be carried out, under what conditions, and what resources are needed. Include guidelines about how well the candidate has to perform a task for it to be judged satisfactory.

Range is restricted to essential operating conditions and any other variables essential to the work environment.

Non-essential conditions may be found in the UEE Electrotechnology Training Package Companion Volume Implementation Guide.

Servicing and repairing self-contained CO² vapour compression systems must include at least the following:

domestic refrigerators and freezers

refrigerated cabinets

heat pumps

water heaters

checking:

suction and discharge pressures

ambient, evaporator and condensed/gas cooler temperatures

evaporator and gas cooler temperature difference

critical point, triple point and trans-critical and sub-critical refrigerant conditions of CO²

charging and discharging trans-critical CO² system with refrigerant and lubricant in a safe and environmentally responsible manner

Copy and paste from the following performance criteria to create an observation checklist for each task. When you have finished writing your assessment tool every one of these must have been addressed, preferably several times in a variety of contexts. To ensure this occurs download the assessment matrix for the unit; enter each assessment task as a column header and place check marks against each performance criteria that task addresses.

Observation Checklist

Tasks to be observed according to workplace/college/TAFE policy and procedures, relevant legislation and Codes of Practice Yes No Comments/feedback
WHS/OHS hazards, risk control methods, relevant standards, codes and legislation are obtained and applied 
 
 
 
 
 
Measuring system operating parameters are conducted in accordance with WHS/OHS requirements and workplace safety procedures 
 
 
 
 
 
 
 
 
 
 
Worksite is cleaned and made safe in accordance with workplace procedures 
 
 
 

Forms

Assessment Cover Sheet

UEERA0068 - Repair and service self-contained carbon dioxide refrigeration and heat pump systems
Assessment task 1: [title]

Student name:

Student ID:

I declare that the assessment tasks submitted for this unit are my own work.

Student signature:

Result: Competent Not yet competent

Feedback to student

 

 

 

 

 

 

 

 

Assessor name:

Signature:

Date:

Assessment Record Sheet

UEERA0068 - Repair and service self-contained carbon dioxide refrigeration and heat pump systems

Student name:

Student ID:

Assessment task 1: [title] Result: Competent Not yet competent

(add lines for each task)

Feedback to student:

 

 

 

 

 

 

 

 

Overall assessment result: Competent Not yet competent

Assessor name:

Signature:

Date:

Student signature:

Date: