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

Student: __________________________________________________

Signature: _________________________________________________

Tips for gathering evidence to demonstrate your skills

The important thing to remember when gathering evidence is that the more evidence the better - that is, the more evidence you gather to demonstrate your skills, the more confident an assessor can be that you have learned the skills not just at one point in time, but are continuing to apply and develop those skills (as opposed to just learning for the test!). Furthermore, one piece of evidence that you collect will not usualy demonstrate all the required criteria for a unit of competency, whereas multiple overlapping pieces of evidence will usually do the trick!

From the Wiki University

 

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

What evidence can you provide to prove your understanding of each of the following citeria?

Prepare to service self-contained CO² refrigeration and heat pump system

  1. WHS/OHS hazards, risk control methods, relevant standards, codes and legislation are obtained and applied
WHS/OHS hazards, risk control methods, relevant standards, codes and legislation are obtained and applied

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Safety hazards not previously identified are reported, risk assessed and advice on risk control measures sought from work supervisor

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Nature of work is obtained from documentation or from work supervisor to determine the scope of work to be undertaken

Completed
Date:

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Advice is sought from work supervisor to ensure the work is coordinated effectively with others

Completed
Date:

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Sources of materials required for the refrigeration work are accessed in accordance with workplace and procedures

Completed
Date:

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Tools, equipment and testing devices needed to carry out refrigeration work are obtained and checked for correct operation and safety

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Service and repair self-contained CO² refrigeration and heat pump system

  1. Measuring system operating parameters are conducted in accordance with WHS/OHS requirements and workplace safety procedures
Measuring system operating parameters are conducted in accordance with WHS/OHS requirements and workplace safety procedures

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

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

Completed
Date:

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Refrigerant is removed from system safely in accordance with regulatory requirements, industry standards and practices

Completed
Date:

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Precautions are taken to prevent damage to components while pressure testing the refrigeration and heat pump system

Completed
Date:

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Pressure testing is conducted at a pressure compatible with CO² and in accordance with industry standards and practices

Completed
Date:

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Refrigerant leaks are located and rectified using testing methods appropriate to the system and in accordance with industry standards and practices

Completed
Date:

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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

Completed
Date:

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Refrigeration and heat pump system is charged safely with refrigerant grade CO² and compatible lubricants in accordance with industry standards and practices

Completed
Date:

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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

Completed
Date:

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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

Completed
Date:

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Operating conditions are determined without damage to apparatus, circuits, the surrounding environment or services using sustainable energy practices

Completed
Date:

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Complete and report servicing and repair of self-contained CO² refrigeration and heat pump system work activities

  1. Worksite is cleaned and made safe in accordance with workplace procedures
Worksite is cleaned and made safe in accordance with workplace procedures

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Contaminated refrigerant and lubricant are dealt with in accordance with legislative/regulatory and industry standard requirements

Completed
Date:

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Operation conditions are documented and include identification of any parameter that is not within the specified range for the system

Completed
Date:

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Work supervisor is notified of the completion of work in accordance with workplace procedures

Completed
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Assessed

Teacher: ___________________________________ Date: _________

Signature: ________________________________________________

Comments:

 

 

 

 

 

 

 

 

Instructions to Assessors

Required Skills and Knowledge

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.

Range Statement

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