This describes the essential skills and knowledge and their level required for this unit

Evidence must show that knowledge has been acquired of safe working practices and determining the operating conditions of both sub critical vapour compression and liquid recirculating carbon dioxide refrigerating systems

All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies

KSEJA

Servicing and repair techniques for carbon dioxide refrigeration Systems

Evidence shall show an understanding of carbon dioxide refrigeration systems operation components service and repair techniques applying safe working practices and relevant Standards Codes and Regulations to an extent indicated by the following aspects

T Carbon Dioxide Refrigeration Systems

Introduction to Carbon Dioxide refrigeration System

Benefits of using Carbon Dioxide as a Refrigerant

Thermophysical Properties

Introduction to Liquid recirculation Cascade system employing Carbon Dioxide refrigerant at SubCritical condition

Systems and Major components

Basic operation

Typical applications

T Operating conditions of carbon dioxide Refrigeration Systems

CO Refrigeration Compressors and lubricants

Types construction and their applications reciprocating screw

Types of compatible compressor oil POE PAO

Safe handling of lubricants for CO applications MSDS POEs PAO

System components construction and operation

CO Low temperature evaporators design features

Medium Temperature Liquid recirculation evaporators

Hand expansion valves medium temp

Electronic expansion valves low temp

Cryogenic pressure relief devices

Plate heat exchangers

Liquid Suction heat exchangers

Liquid CO Refrigerant Pumps

Q Min and Q Max valves

Interconnecting piping

Refrigerant receiver

Isolation valves

Applicable Standards and Codes

Hazards associated with Carbon Dioxide MSDS

ASNZS

ASNZS

IIAR Bulletins

ANSIASHRAE Standards

IOR Safety code for Refrigerating Systems utilising Carbon Dioxide

T Servicing and repair techniques for carbon dioxide refrigeration systems

Service Gauges

Appropriate Type

Care and Maintenance of Gauges and hoses

Service procedures

Charging CO into a system in both vapour and liquid form

Discharging CO from a system safely

Pressure testing

System and component isolation

Leak detection methods for CO

Cylinder Regulators CO

All currently available regulators provide vapour feed only

Pressure readings bottle and line

Refrigerant Cylinders CO

Refrigerant conditions

Hazards and related safe working practices dangerous system pressures

Pressure to temperature conversion Saturated PT is only between kPa and kPa

System standing pressure as a result of power loss

Moisture problems with CO systems

The evidence guide provides advice on assessment and must be read in conjunction with the Performance Criteria Required Skills and Knowledge the Range Statement and the Assessment Guidelines for this Training Package

The Evidence Guide forms an integral part of this unit It must be used in conjunction with all parts of this unit and performed in accordance with the Assessment Guidelines of this Training Package

Overview of Assessment

Longitudinal competency development approaches to assessment such as Profiling require data to be reliably gathered in a form that can be consistently interpreted over time This approach is best utilised in Apprenticeship programs and reduces assessment intervention It is the industrypreferred model for apprenticeships However where summative or final assessment is used it is to include the application of the competency in the normal work environment or at a minimum the application of the competency in a realistically simulated work environment In some circumstances assessment in part or full can occur outside the workplace However it must be in accordance with industry and regulatory policy

Methods chosen for a particular assessment will be influenced by various factors These include the extent of the assessment the most effective locations for the assessment activities to take place access to physical resources additional safety measures that may be required and the critical nature of the competencies being assessed

The critical safety issues inherent in working with electricity electrical equipment gas or any other hazardous substancematerial present a challenge for those determining competence Sources of evidence need to be rich in nature to minimise error in judgment

Activities associated with normal everyday work have a bearing on the decision as to how much and how detailed the data gathered will contribute to its richness Some skills are more critical to safety and operational requirements while the same skills may be more or less frequently practised These points are raised for the assessors to consider when choosing an assessment method and developing assessment instruments Sample assessment instruments are included for Assessors in the Assessment Guidelines of this Training Package

Critical aspects of evidence required to demonstrate competency in this unit

Before the critical aspects of evidence are considered all prerequisites must be met

Evidence for competence in this unit must be considered holistically Each element and associated performance criteria must be demonstrated on at least two occasions in accordance with the Assessment Guidelines UEE Evidence must also comprise

Evidence for competence in this unit must be considered holistically. Each element and associated performance criteria must be demonstrated on at least two occasions in accordance with the 'Assessment Guidelines - UEE07 '. Evidence must also comprise:

A representative body of work performance demonstrated within the timeframes typically expected of the discipline work function and industrial environment In particular this must incorporate evidence that shows a candidate is able to

Implement Occupational Health and Safety workplace procedures and practices including the use of risk control measures as specified in the performance criteria and range statement

Apply sustainable energy principles and practices as specified in the performance criteria and range statement

Demonstrate an understanding of the essential knowledge and associated skills as described in this unit It may be required by some jurisdictions that RTOs provide a percentile graded result for the purpose of regulatory or licensing requirements

Demonstrate an appropriate level of skills enabling employment

Conduct work observing the relevant Anti Discrimination legislation regulations polices and workplace procedures

Demonstrated consistent performance across a representative range of contexts from the prescribed items below

Pressure testing chargingdischarging refrigerantlubricants and determining the operating conditions of Carbon Dioxide vapour compression and volatile secondary liquid recirculation system as described in and including

A

Selecting and using appropriate measuring devices correctly

B

Recording measurements

C

Using calculation methods accurately

D

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

E

Locating and rectifying leaks

F

Decontaminating and evacuating the system

G

Identifying the conditions of the refrigerant R at various locations in the vapour compression and volatile secondary liquid recirculation system

H

Documenting operating conditions correctly

I

Dealing with unplanned events by drawing on essential knowledge and skills to provide appropriate solutions incorporated in a holistic assessment with the above listed items

Context of and specific resources for assessment

This unit should be assessed as it relates to normal work practice using procedures information and resources typical of a workplace This should include

OHS policy and work procedures and instructions

Suitable work environment facilities equipment and materials to undertake actual work as prescribed by this unit

These should be part of the formal learningassessment environment

Note

Where simulation is considered a suitable strategy for assessment conditions must be authentic and as far as possible reproduce and replicate the workplace and be consistent with the approved industry simulation policy

The resources used for assessment should reflect current industry practices in relation to servicing and repairing as well as determining the operating conditions of Carbon Dioxide vapour compression and liquid recirculationcascade system

Method of assessment

This unit shall be assessed by methods given in Volume Part Assessment Guidelines

Note Competent performance with inherent safe working practices is expected in the Industry to which this unit applies This requires assessment in a structured environment which is intended primarily for learningassessment and incorporates all necessary equipment and facilities for learners to develop and demonstrate the essential knowledge and skills described in this unit

Note:
Competent performance with inherent safe working practices is expected in the Industry to which this unit applies. This requires assessment in a structured environment which is intended primarily for learning/assessment and incorporates all necessary equipment and facilities for learners to develop and demonstrate the essential knowledge and skills described in this unit.

Concurrent assessment and relationship with other units

There are no concurrent assessment recommendations for this unit

The critical aspects of occupational health and safety covered in unit UEENEEEB and other discipline specific occupational health and safety units shall be incorporated in relation to this unit

The critical aspects of occupational health and safety covered in unit UEENEEE001B and other discipline specific occupational health and safety units shall be incorporated in relation to this unit..