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Evidence Guide: UEENEEJ112A - Diagnose and rectify faults in complex air conditioning/ 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

 

UEENEEJ112A - Diagnose and rectify faults in complex air conditioning/ refrigeration systems

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

Prepare to diagnose and rectify faults.

  1. OHS procedures for a given work area are identified, obtained and understood
  2. Established OHS risk control measures and procedures are followed in preparation for the work.
  3. Safety hazards that have not previously been identified are documented and risk control measures devised and implemented in consultation with appropriate personnel.
  4. The extent of faults is determined from reports and other documentation and from discussion with appropriate personnel.
  5. Appropriate personnel are consulted to ensure the work is coordinated effectively with others involved on the work site.
  6. Tools, equipment and testing devices needed to diagnose faults are obtained in accordance with established procedures and checked for correct operation and safety.
OHS procedures for a given work area are identified, obtained and understood

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

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

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Safety hazards that have not previously been identified are documented and risk control measures devised and implemented in consultation with appropriate personnel.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

The extent of faults is determined from reports and other documentation and from discussion with appropriate personnel.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Appropriate personnel are consulted to ensure the work is coordinated effectively with others involved on the work site.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Tools, equipment and testing devices needed to diagnose faults are obtained in accordance with established procedures and checked for correct operation and safety.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Diagnose and rectify faults.

  1. OHS risk control measures and procedures for carrying out the work are followed.
  2. The need to test or measure live is determined in strict accordance with OHS requirements and when necessary conducted within established safety procedures.
  3. Circuits/machines/plant are checked as being isolated where necessary in strict accordance OHS requirements and procedures.
  4. Logical diagnostic methods are applied to diagnose complex refrigeration/air conditioning systems faults employing measurements and estimations of system operating parameters referenced to system operational requirements.
  5. Suspected fault scenarios are tested as being the source of system problems.
  6. Causes of the faults are identified and appropriately competent persons are engaged to rectify the fault where it is outside the scope of the refrigeration and air-conditioning system.
  7. Faults in system components of the system are rectified to raise the refrigeration/air conditioning systems to its operation standard.
  8. System is tested to verify that the system operates as intended and to specified requirements.
  9. Decisions for dealing with unexpected situations are made from discussions with appropriate persons and job specifications and requirements.
  10. Methods for dealing with unexpected situations are selected on the basis of safety and specified work outcomes.
  11. Diagnosis and rectification activities are carried out efficiently without waste of materials or damage to apparatus and the surrounding environment or services and using sustainable energy practices.
OHS risk control measures and procedures for carrying out the work are followed.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

The need to test or measure live is determined in strict accordance with OHS requirements and when necessary conducted within established safety procedures.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Circuits/machines/plant are checked as being isolated where necessary in strict accordance OHS requirements and procedures.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Logical diagnostic methods are applied to diagnose complex refrigeration/air conditioning systems faults employing measurements and estimations of system operating parameters referenced to system operational requirements.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Suspected fault scenarios are tested as being the source of system problems.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Causes of the faults are identified and appropriately competent persons are engaged to rectify the fault where it is outside the scope of the refrigeration and air-conditioning system.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Faults in system components of the system are rectified to raise the refrigeration/air conditioning systems to its operation standard.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

System is tested to verify that the system operates as intended and to specified requirements.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Decisions for dealing with unexpected situations are made from discussions with appropriate persons and job specifications and requirements.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Methods for dealing with unexpected situations are selected on the basis of safety and specified work outcomes.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Diagnosis and rectification activities are carried out efficiently without waste of materials or damage to apparatus and the surrounding environment or services and using sustainable energy practices.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Complete and report fault diagnosis and rectification activities.

  1. OHS work completion risk control measures and procedures are followed.
  2. Work site is made safe in accordance with established safety procedures.
  3. Rectification of faults is documented in accordance with established procedures.
  4. Appropriate person or persons notified, in accordance with established procedures, that the system faults have been rectified.
OHS work completion risk control measures and procedures are followed.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Work site is made safe in accordance with established safety procedures.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Rectification of faults is documented in accordance with established procedures.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Appropriate person or persons notified, in accordance with established procedures, that the system faults have been rectified.

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 must 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. 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:

Diagnose and rectify faults in complex refrigeration/air conditioning systems as described in 8) and including:

A

Applying logical diagnostic methods

B

Using fault scenarios to test the cause of system faults

C

Identifying faults and competency needed to rectify them

D

Rectifying faults in system controls

E

Verifying that the system operates correctly

F

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

Note:
Successful completion of relevant vendor training may be used to contribute to evidence on which competency is deemed. In these cases the alignment of outcomes of vendor training with performance criteria and critical aspects of evidence shall be clearly identified

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 diagnosing and rectifying faults in complex refrigeration/air conditioning 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.

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 diagnosing and rectifying faults in complex refrigeration/air conditioning systems.

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

KS01-EJ112A Complex refrigeration and air conditioning system fault finding and repair

Evidence shall show an understanding of fault finding and repairing complex refrigeration and air conditioning system, applying safe working practices and relevant Standards, Codes and Regulations to an extent indicated by the following aspects:

T1 Fault finding techniques

Factors to consider in clarifying the nature of a fault encompassing:

initial fault report

confirmation of symptoms of the fault

comparison of symptoms with normal operation

Effect to cause reasoning — assumptions of possible causes

Methods for testing assumptions encompassing:

Visual inspection

Sectional testing

Split-half tests

Component isolation

Dealing with intermittent faults

Note: Typical causes of intermittent faults are vibration, shock, changes in temperature and electromagnetic interference.

T2 Refrigeration system analysis

Pressure Enthalpy definitions

high pressure & low pressure refrigerants

triple point of new refrigerants

glide of trinary blends

differential evaporation of refrigerant blends

variable refrigerant volume

Refrigeration cycle

expansion process

vaporising process

compression process

condensing process

compression ratio

Enthalpy processes

co-efficient of performance

effect of suction temperature on cycle efficiency

effect of condensing temperature on cycle efficiency

Actual refrigerating cycles

design operating conditions

effects of superheating suction vapour

superheating without useful cooling

superheating that produces useful cooling

superheating in suction piping outside the refrigerated space

superheating the vapour inside the refrigerated space

effects of subcooling the liquid

effects liquid - suction heat exchangers

effects of pressure losses resulting from friction

Refrigeration cycle faults

symptoms and causes

measurements and fault confirmation tests

T3 Air conditioning system analysis

Psychrometric chart

properties, definitions and units

plotting conditions

RA, SA, OA, MA

Psychometric processes

heating

cooling only

cooling and dehumidification

cooling , dehumidification and reheat

Design operating conditions

indoor and outdoor wet and dry bulb temperatures

volume flow rate supply, return and outdoor air

Air conditioning system faults

symptoms and causes

measurements and fault confirmation tests

T4 Power and control system analysis

power and control circuit diagrams

sequence of operation

manufacturers diagrams, specifications and instructions

power and control circuit faults

symptoms and causes

measurements and fault confirmation tests

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 diagnosing and rectifying at least four faults in complex refrigeration/air conditioning systems, incorporating multiple major components (i.e. compressors, condenser, or evaporators) circuits or systems and associated components and controls.

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.