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Evidence Guide: UEENEEJ179A - Repair and service ammonia refrigeration 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

 

UEENEEJ179A - Repair and service ammonia refrigeration systems

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

Prepare to service and repair Ammonia refrigeration systems

  1. OHS procedures for a given work area are identified, obtained and understood through established routines and procedures
  2. Established OHS risk control measures and procedures are followed in preparation for the work.
  3. Safety hazards which have not previously been identified are reported and advice on risk control measures is sought from the work supervisor.
  4. The nature of work is obtained from documentation or from work supervisor to establish the scope of work to be undertaken.
  5. Advice is sought from the work supervisor to ensure the work is coordinated effectively with others.
  6. Sources of materials that may be required for the work are accessed in accordance with established routines and procedures.
  7. Tools, equipment and testing devices needed to carry out the work are obtained and checked for correct operation and safety
OHS procedures for a given work area are identified, obtained and understood through established routines and procedures

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Established OHS risk control measures and procedures are followed in preparation for the work.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Safety hazards which have not previously been identified are reported and advice on risk control measures is sought from the work supervisor.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

The nature of work is obtained from documentation or from work supervisor to establish the scope of work to be undertaken.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

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

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Sources of materials that may be required for the work are accessed in accordance with established routines and procedures.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

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

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Service and repair Ammonia refrigeration systems.

  1. Established OHS risk control measures and procedures for carrying out the work are followed.
  2. Measuring system operating parameters is conducted in strict accordance with OHS requirements and established safety procedures
  3. Checks are carried out to ensure the system or component parts are isolated, when necessary in strict accordance OHS requirements and procedures.
  4. Refrigerant is removed from a system safely in accordance with regulatory requirements and industry practices.
  5. Precautions are taken to prevent damage to components while pressure testing the system
  6. Pressure testing is conducted at a pressure compatible with Ammonia and in accordance with standards
  7. Leaks are located and rectified using testing methods appropriate to the system and in accordance with industry practices
  8. Oil is removed from an operational Ammonia refrigeration system in accordance with industry practices
  9. System is charged safely with Ammonia and compatible lubricants in accordance with industry practices
  10. Established procedures are used to determine actual and specified range of operating conditions from measured and calculated values as they apply to Ammonia vapour compression and liquid recirculation systems.
  11. Established methods for dealing with unexpected situations are discussed with appropriate person or persons and documented.
  12. Unexpected situations are dealt with safely and with the approval of an authorised person.
  13. Operating conditions are determined without damage to apparatus, circuits, the surrounding environment or services and using sustainable energy practices.
Established OHS risk control measures and procedures for carrying out the work are followed.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Measuring system operating parameters is conducted in strict accordance with OHS requirements and established safety procedures

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Checks are carried out to ensure the system or component parts are isolated, when necessary in strict accordance OHS requirements and procedures.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Refrigerant is removed from a system safely in accordance with regulatory requirements and industry practices.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Precautions are taken to prevent damage to components while pressure testing the system

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Pressure testing is conducted at a pressure compatible with Ammonia and in accordance with standards

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

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

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Oil is removed from an operational Ammonia refrigeration system in accordance with industry practices

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

System is charged safely with Ammonia and compatible lubricants in accordance with industry practices

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Established procedures are used to determine actual and specified range of operating conditions from measured and calculated values as they apply to Ammonia vapour compression and liquid recirculation systems.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Established methods for dealing with unexpected situations are discussed with appropriate person or persons and documented.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Unexpected situations are dealt with safely and with the approval of an authorised person.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

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

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Complete work and report on servicing and repairing Ammonia refrigeration systems

  1. OHS work completion risk control measures and procedures are followed.
  2. Work site is cleaned and made safe in accordance with established procedures.
  3. Contaminated refrigerant and lubricant is dealt with in accordance with legislative/regulatory requirements
  4. Operation conditions are documented, including identification of any parameter that is not within the specified range for the system.
  5. Work supervisor is notified of the completion of the work in accordance with established procedures.
OHS work completion risk control measures and procedures are followed.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Work site is cleaned and made safe in accordance with established procedures.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Contaminated refrigerant and lubricant is dealt with in accordance with legislative/regulatory requirements

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Operation conditions are documented, including identification of any parameter that is not within the specified range for the system.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

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

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Assessed

Teacher: ___________________________________ Date: _________

Signature: ________________________________________________

Comments:

 

 

 

 

 

 

 

 

Instructions to Assessors

Evidence Guide

9) 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

9.1)

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 industry-preferred 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 nature of working with electricity, electrical equipment, gas or any other hazardous substance/material carries risk in deeming a person competent. Sources of evidence need to be ‘rich’ in nature to minimise error in judgment.

Activities associated with normal everyday work influence decisions about how/how much 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

9.2)

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

Evidence for competence in this unit shall be considered holistically. Each element and associated performance criteria shall be demonstrated on at least two occasions in accordance with the ‘Assessment Guidelines – UEE07 ’. Evidence shall 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 shall 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 to such an extent that the learner’s performance outcome is reported in accordance with the preferred approach; namely a percentile graded result, where required by the regulated environment

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, charging/discharging refrigerant/lubricants and determining the operating conditions of Ammonia vapour compression and liquid recirculation refrigeration system.

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 (R717) at various locations in the vapour compression and 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 the holistic assessment with the above listed items

Context of and specific resources for assessment

9.3)

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 learning/assessment 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.

Evidence should show demonstrated competency in servicing and repairing as well as determining the operating conditions of Ammonia vapour compression and liquid recirculation systems.

Method of assessment

9.4)

This unit shall be assessed by methods given in Volume 1, Part 3 ‘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 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

9.5)

There are no concurrent assessment recommendations for 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..

Required Skills and Knowledge

7) This describes the essential skills and knowledge and their level, required for this unit.

Evidence shall show that knowledge has been acquired of safe working practices and determining the operating conditions of Ammonia refrigerating systems.

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

KS01-EJ179A Servicing and repair techniques for Ammonia refrigeration systems

Evidence shall show an understanding of the Ammonia refrigeration systems, their operating conditions, and servicing and repair techniques, applying safe working practices and relevant Standards, Codes and Regulations to an extent indicated by the following aspects:

T1. Ammonia Refrigeration Systems

Vapour Compression Systems

Revision of Vapour Compression Cycle

Properties of Ammonia

Safe Handling of Ammonia

Types of Ammonia Systems

Direct Expansion Systems

Flooded Systems

Liquid Recirculation Systems

Multi Staged Systems

Single Staged Systems

Multi Staged Systems

Cascade Systems

T2. Operating conditions of Ammonia Refrigeration Systems

Compressors

Function of the compressor

Types, construction and their applications

Capacity control of compressors

Factors affecting performance

Economiser operation

Types of oil separators

Methods of oil cooling

Operation and maintenance

Lubrication and lubricants

Lubrication methods

Safe handling of lubricants

Selection of lubricants

Oil / Ammonia separation

Adding and removing oil from Ammonia systems

Methods of oil recovery

Evaporators / Cooling Units

Types of evaporators (air / fluid cooling)

Direct contact freezing

Secondary refrigerants

Evaporator defrost methods and controls

Operation and maintenance

Condensers and high pressure receivers

Evaporative condensers

Water cooled condensers

Air cooled condensers

High pressure receivers

Operation and maintenance

Low Pressure Receivers

Suction accumulators

Intercoolers

Liquid refrigerant pumps

Liquid level controls

Operation and maintenance

Purging

Non condensable gases

Moisture: measurement and removal

Manual; purging of Ammonia systems

Automatic refrigerated purgers

Operation and maintenance

Refrigerant Flow Devices

Expansion valves

Automatic liquid feed control devices

Pressure regulating devices

Operation and maintenance

Methods of oil recovery

Ancillary Components

Strainers, isolating valves

Liquid level indicators

Pressure relief valves

Ammonia leak detectors

Safety controls

Operation and maintenance

T3 Servicing and repairs

Servicing Procedures

Leak detection methods

Adding refrigerant

Removing refrigerant

Range Statement

8) This relates to the unit as a whole providing the range of contexts and conditions to which the performance criteria apply. It allows for different work environments and situations that will affect performance.

This unit must be demonstrated in relation to determining operating conditions using measurement and basic calculation methods of Ammonia refrigeration system. These conditions include suction and discharge pressures, ambient, evaporator and condensing temperatures, evaporator, and condenser temperature difference. Further, this unit must be demonstrated in relation to charging and discharging Ammonia (R717) system with refrigerant and lubricant in a safe and environmentally responsible manner

Generic terms used throughout this Vocational Standard shall be regarded as part of the Range Statement in which competency is demonstrated. The definition of these and other terms that apply are given in Volume 2, Part 2.1.