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:

Determine the basic operating conditions of vapour compression systems as described in 8) and including:

A

Selecting and using appropriate measuring devices correctly

B

Recording measurements

C

Using calculation methods accurately

D

Identifying the conditions of a refrigerant at various locations in the vapour compression system

E

Documenting operating conditions 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

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 determining the basic operating conditions of vapour compression 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.

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 basic operating conditions of vapour compression systems.

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

KS01-EJ103A Basic operating conditions of vapour compression systems

Evidence shall show an understanding of basic operating conditions of vapour compression systems, applying safe working practices and relevant Standards, Codes and Regulations to an extent indicated by the following aspects:

T1 Refrigeration Industry

The history of the refrigeration industry (note that A/C is covered in another unit)

Applications, classifications and equipment used in the refrigeration industry

T2 Introduction to the Vapour Compression System

Basic Operation

Major Components

T3 Heat

Matter (atoms, molecules, energy and its different forms)

Heat energy (definition, unit of measurement)

Enthalpy (definition, unit of measurement)

Heat flow (hot to cold)

Heat transfer

methods (conduction, convection, radiation)

requirements

effects

T4 Temperature and relative humidity

Temperature

Scale types (imperial, metric, absolute) and their units of measurement

Conversion to/from absolute values

Temperature difference/change (td, Δt, unit of measurement)

Relative humidity

Thermometer types and applications (digital, stem, dial, max/min, non-contact, data loggers)

Relative Humidity measurement devices and applications (dry bulb/wet bulb, sling, digital)

Hazards and related safe working practices (working near rotating machinery - fans, pulleys, belts etc)

Care and maintenance (bending stems, overheating, removing batteries after use, uncoiling capillary)

Calibration (boiling water, iced water, send to a specialist etc)

Appropriate and safe methods of use

Typical locations on a system

Fitting temperature and relative humidity instruments

T5 Sensible and Latent Heat

Definition of specific heat capacity, latent heat and sensible heat (including units of measurement)

Types of latent heat

Heat calculations

T6 Pressure

Define

Scale types (imperial, metric, absolute) and their units of measurement

Vacuum scales (Pascals, microns)

Conversion to/from absolute values

The basic Gas Laws – Boyles, Charles and Daltons (excl combined or general gas law)

Pressure gauge types and applications (pressure, compound, vacuum, manometer, magnehelic, barometer)

Hazards and related safe working practices (dangerous system pressures)

Care and maintenance (ingress of oil and contaminants (dirt), avoiding needle bounce (esp. HP) etc)

Calibration (atmospheric pressure, send to a specialist etc)

Appropriate and safe methods of use

Typical locations

T7 Refrigerant conditions

Saturation temperature

Saturated liquid / saturated vapour

Superheated vapour

Sub-cooled liquid

Pressure temperature relationships

P/T charts

Enthalpy

T8 The vapour compression cycle

Primary system components

High and low pressure sides

Basic system operation

T9 Working safely with refrigeration vapour compression systems

Risk management principles and processes

Hazards and risk control measures associated with:

refrigeration vapour compression systems and components

refrigerants

measuring and testing equipment

T10 Leak detectors

Detector types and applications (electronic, halide, bubble, ultra violet)

Hazards and related safe working practices (working around rotating machinery, open flame, ultra violet light etc)

Care and maintenance (delicate electronic equipment, changing sensor tip filters, changing gas cartridges etc)

Calibration (auto calibrating , send to a specialist etc)

Leak detection procedures

T11 Service gauges

Service Gauges

Types (dial gauges or electronic, manifolds with additional vacuum and charging ports & sight glasses)

Typical uses for service gauges (high & low side pressure readings, charging, evacuating)

Care and maintenance (oil and contaminants (dirt) in hoses, avoiding needle bounce, changing hose seals)

Calibration (hoses open to atmosphere, adjusting screw etc)

Hose shut-off valves and adaptors (access control valves, kwik couplers, Hansen lines etc)

System Access Fittings

Types (Schrader, piercing, service valve, post valve, quick couplers etc)

Typical applications for each

Hazards and related safe working practices (oil or liquid spray, keeping clean, leaks etc)

Care and maintenance (gland nuts loosened/tightened, seal caps fitted, regulations on piercing valves)

Using Service Gauges

Service gauge manifold hose fitting

Purging

Pressure readings

Service gauge manifold hose removal

Pressure to temperature conversion

T12 Refrigeration Compressors

Function of the compressor

Compressor styles (open drive, semi-hermetic, hermetic)

Types, construction and their applications (reciprocating, rotary, centrifugal, screw, scroll)

Basic types of compressor oil (Mineral, Polyolester (POE), Alkyl Benzene, Polyalkylene Glycols (PAG)) (brief overview - covered in more detail in J8)

Methods of lubrication (splash, forced)

Safe handling (MSDS - POE's, PAG's, Mineral, AB's - Residual acid's in used oil)

T13 Condensers and related components

Function of the condenser

Types, construction and their applications (static, forced draught, water cooled)

Function of a cooling tower

Types, construction and their applications (natural, induced, forced, evaporative)

Function of water pumps

Basic Types and their applications

Function of liquid receivers

Types, construction and their applications (horizontal, vertical, combined condenser/receivers)

T14 Evaporators and related components

Function of the evaporator

Evaporator styles (direct expansion, flooded)

Types, construction and their applications (static, forced draught, water cooling)

Refrigerant/air/water flow paths (forced/induced draft, parallel/counter flow)

Need for water treatment in water systems

Methods used to provide water treatment (brief overview)

Regulations governing water treatment (brief overview)

Secondary refrigerants (brief overview)

Properties & applications of secondary refrigerants (water, sodium/calcium chloride, ethylene/propylene glycol)

Hazards associated with their use (MSDS)

T15 Common Refrigerant Metering Devices

Function of a refrigerant metering device

Overview of common types and their applications (capillary tube and TX Valve)

T16 Basic Operating Conditions

Ambient conditions

Common climate values (highest max temp, lowest min temp, mean daily temp, mean highest/lowest)

Typical climates for various common localities

Evaporator Td

Effect of changes in Evap. Td and typical industry reference values for water cooled, forced draught and static coils

Condenser Td

Effect of changes in Cond. Td and typical industry reference values for water cooled, forced draught and static coils

Typical storage conditions (temp & RH) for common products (dairy, produce, meat and frozen food rooms)

Typical high and low side system operating values (pressures and temperatures allowing 1K equivalent PD)

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 vapour compression systems whether used for refrigeration or air conditioning. These conditions include suction and discharge pressures, ambient, evaporator and condensing temperatures, evaporator, and condenser temperature difference.

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.