Application
This unit describes the performance outcomes required to overhaul and return air conditioning and heating, ventilation and air conditioning (HVAC) system compressors to original manufacturer tolerances and clearances. It involves preparing for the task, dismantling and evaluating the compressor, carrying out the overhaul process, reassembling and testing the compressor, and completing workplace processes and documentation.
It applies to those working in an automotive service and repair industry. The air conditioning and HVAC system compressors include those fitted to agricultural machinery, heavy commercial vehicles, light vehicles or mobile plant machinery.
Licensing requirements apply to this unit. Users are advised to check with relevant regulatory authority.
Elements and Performance Criteria
Elements Elements describe the essential outcomes. | Performance Criteria Performance criteria describe the performance needed to demonstrate achievement of the element. Where bold and italicised text is used, further information is detailed in the range of conditions section. |
1. Prepare to dismantle air conditioning compressor | 1.1 Job requirements are determined from workplace instructions 1.2 Australian automotive code of practice: Control of refrigerant gases during manufacture, installation, servicing or de-commissioning of motor vehicle air conditioners is sourced and interpreted 1.3 Dismantling information is sourced and interpreted 1.4 Dismantling options are analysed and those most appropriate to the circumstances are selected 1.5 Hazards associated with the work are identified and risks are managed 1.6 Dismantling tools and equipment are selected and checked for serviceability |
2. Dismantle and evaluate compressor and components | 2.1 Compressor is dismantled in a logical sequence according to manufacturer and workplace procedures, and safety and environmental requirements, 2.2 Components are cleaned for evaluation according to workplace procedures and safety and environmental requirements 2.3 Components are measured and compared with manufacturer specifications and serviceability is determined 2.4 Component repair method is determined 2.5 Unserviceable parts are identified and replacement parts sourced |
3. Carry out overhaul | 3.1 Overhaul information is sourced and interpreted 3.2 Overhaul options are analysed and those most appropriate to the circumstances are selected 3.3 Overhaul tools and equipment are selected and checked for serviceability 3.4 Components are machined, repaired and replaced as required, and adjustments are carried out according to manufacturer specifications, workplace procedures, safety and environmental requirements, and Australian automotive code of practice |
4. Assemble compressor and components | 4.1 Compressor is assembled according to manufacturer specifications, workplace procedures, and safety and environmental requirements 4.2 Tolerances and clearances are measured against manufacturer specifications and necessary adjustments are made 4.3 Assembly of compressor is completed within workplace timeframes and without causing damage to other components or systems 4.4 Post-assembly testing is carried out according to workplace procedures and safety and environmental requirements, and any problems detected as having been introduced during the assembly process are rectified |
5. Complete work processes | 5.1 Final inspection is made to ensure work is to workplace expectations and compressor is presented ready for use or storage 5.2 Work area is cleaned, waste and non-recyclable materials are disposed of, and recyclable material is collected 5.3 Tools and equipment are checked and stored, and any faulty electrical equipment is identified, tagged and isolated according to workplace procedures 5.4 Workplace documentation is processed according to workplace procedures |
Evidence of Performance
Before competency can be determined, individuals must demonstrate they can perform the following according to the standards defined in this unit’s elements, performance criteria, range of conditions and foundation skills:
overhaul the air conditioning compressors of two different vehicles or machinery, including:
piston, scroll and rotary vane compressors
electric compressors
variable displacement compressors
clutchless compressors
recover and evacuate refrigerants according to required code of practice and regulations, and recharge the system with the appropriate manufacturer refrigerant and oil type.
Evidence of Knowledge
Individuals must be able to demonstrate knowledge of:
work health and safety (WHS) and occupational health and safety (OHS) requirements relating to overhauling air conditioning and heating, ventilation and air conditioning (HVAC) system components, including procedures for:
working with refrigerants at boiling point given risk of frostbite
working with system lubricants, including carcinogenic oils
handling flammable refrigerants
using personal protective equipment (PPE)
identifying and using fire safety equipment
environmental requirements, including procedures for preventing loss of refrigerant to the atmosphere
techniques for reading and interpreting technical information, including:
refrigerant saturation temperatures in relation to ambient temperatures and changing levels of humidity
graphic symbols and diagrams
principal types of vehicle air conditioning and HVAC systems, including:
piston, scroll and rotary vane compressors
electric compressors
variable displacement compressors
clutchless compressors
principal refrigerant types and their respective operating pressures and lubricating oils, including:
R12
R134a
R1234yf
air conditioning and HVAC system component overhaul procedures, including:
methods for cleaning and preparing air conditioning and HVAC system compressor for overhaul
air conditioning and HVAC system compressor dismantling procedures
air conditioning and HVAC system compressor inspection, measuring and evaluation procedures, including methods for measuring and calculating tolerances and clearances
air conditioning and HVAC compressor repair and adjustment procedures, including:
piston, scroll and rotary vane compressors
electric compressors
variable displacement compressors
clutchless compressors
procedures for tolerance measuring and calculating and adjusting components
post-overhaul bench testing procedures, including:
use of manifold gauges and surface probe thermocouples for complete system analysis
analysis of system operation while using gauges, temperature probes, electrical test equipment, scan tools, oscilloscopes and other industry-relevant test equipment
post-overhaul testing of air conditioning and HVAC systems in vehicle or machinery, including:
diagnostic procedures for air conditioning and HVAC systems, including:
accessing and interpreting diagnostic trouble codes (DTCs)
diagnostic flow charts
visual, aural and functional assessments
ambient temperature
centre vent temperature
condenser and suction line temperature
manifold gauge pressure readings
refrigerant leaks.
Assessment Conditions
Assessors must satisfy NVR/AQTF assessor requirements and hold an Australian Refrigerant Council (ARC) Refrigerant Handling licence.
Competency is to be assessed in the workplace or a simulated environment that accurately reflects performance in a real workplace setting.
Assessment must include direct observation of tasks.
Where assessment of competency includes third-party evidence, individuals must provide evidence that links them to the air conditioning and HVAC systems that they have worked on, e.g. repair orders.
Assessors must verify performance evidence through questioning on skills and knowledge to ensure correct interpretation and application.
The following resources must be made available:
automotive repair workplace or simulated workplace
workplace instructions
Australian automotive code of practice:
manufacturer specifications for air conditioning and HVAC system components
two different vehicles or machinery requiring overhaul, with operational air conditioning and HVAC systems and with components specified in the performance evidence
tools, equipment and materials appropriate for overhauling and adjusting a range of air conditioning and HVAC compressors.
Foundation Skills
This section describes those language, literacy, numeracy and employment skills that are essential to performance and are not explicit in the performance criteria.
Skills | Description |
Learning skills to: | locate sources of information relevant to compressor efficiently. |
Reading skills to: | interpret and assess information from manufacturer and workshop literature when seeking air conditioning and HVAC system compressor specifications and procedures. |
Writing skills to: | legibly and accurately fill out workplace documentation when reporting diagnostic findings, making repair recommendations, and recording parts and material used. |
Oral communication skills to: | clarify instructions, report evaluation findings and make overhaul recommendations. |
Numeracy skills to: | measure air conditioning and HVAC system components and use basic mathematical operations, including addition, subtraction, multiplication and division, to calculate distances, areas, volumes, tolerances and deviations from manufacturer specifications match refrigerant types and identification numbers to workplace instructions, vehicle and component part lists, and code of practice requirements interpret weight measurements, including tare and gross weights, and readings on digital and analogue pressure gauges interpret measurements of temperature and pressure relating to air conditioner and HVAC system performance. |
Planning and organising skills to: | plan own work requirements and prioritise and sequence actions to achieve required outcomes and ensure tasks are completed within workplace timeframes. |
Technology skills to: | use precision measuring equipment, such as vernier calipers and micrometers use specialised air conditioning and HVAC system compressor overhaul equipment. |
Range Statement
This section specifies work environments and conditions that may affect performance. Essential operating conditions that may be present (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) are included. Bold italicised wording, if used in the performance criteria, is detailed below.
Safety and environmental requirements must include: | work health and safety (WHS) and occupational health and safety (OHS) requirements, including procedures for: working with refrigerants at boiling point given risk of frostbite working with system lubricants, including carcinogenic oils handling flammable refrigerants using personal protective equipment (PPE) identifying fire safety equipment environmental requirements, including procedures for preventing loss of refrigerant to the atmosphere. |
Sectors
Technical - Air Conditioning and HVAC
Competency Field
Electrical