Unit of competency details

Unit descriptor 

This unit covers performing the selection, maintenance, repair/replacement and adjustment of refrigerant flow controls, either liquid or vapour (mechanical or electronic types) to achieve desired operational performance.

Application of the unit 

The selection, maintenance, repair, replacement and adjustment of refrigerant flow controls are conducted according to refrigeration principles and practices. Adjustments are made to manufacturers' specifications. All work is conducted according to safety regulations and Australian standards and codes.

The associate equipment may include controllers and/or valves required to ensure proper operation of the flow device.

Where any rectification, modification involves electrical disconnection and reconnection, then Unit MEM18049C (Disconnect/reconnect fixed wired equipment up to 1000 volts a.c./1500 volts d.c.) should also be considered.

Band : A 

Unit Weight : 6 

Prerequisite units 

Path 1 

MEM05006C

Perform brazing and/or silver soldering

MEM10010B

Install pipework and pipework assemblies

MEM12023A

Perform engineering measurements

MEM18001C

Use hand tools

MEM18002B

Use power tools/hand held operations

MEM18055B

Dismantle, replace and assemble engineering components

MEM18086B

Test, recover, evacuate and charge refrigeration systems

Employability skills 

This unit contains employability skills.

Elements describe the essential outcomes of a unit of competency.

Performance criteria describe the performance needed to demonstrate achievement of the element. Where bold italicised text is used, further information is detailed in the required skills and knowledge section and the range statement. Assessment of performance is to be consistent with the evidence guide.

ELEMENT 

PERFORMANCE CRITERIA 

1. Undertake preventative maintenance checks on refrigerant flow controls

1.1. The location and operation of the control is understood.

1.2. The operational parameters of the refrigerant control are understood.

1.3. Visual inspection and testing with appropriate test equipment is carried out by following refrigeration principles, procedures and safety requirements.

1.4. The refrigerant type is correctly identified.

2. Undertake fault finding on refrigerant flow controls

2.1. Flow control is identified correctly.

2.2. The characteristics of the flow control are understood.

2.3. The operational function of the flow control and associated valves are inspected and tested.

2.4. Appropriate test equipment can be selected/used safely.

2.5. Correct operation of the flow control is assessed against specification.

3. Repair or replace refrigerant flow control

3.1. Using manufacturers' catalogues and specifications, appropriate flow control or components relevant to system operation are selected for replacement/repair.

3.2. The refrigerant is removed/contained safely from the system in accordance with refrigeration principles and procedures and relevant standards and codes.

3.3. Faulty components are dismantled and repaired /replaced to manufactures' specifications as required.

3.4. Replacement parts are selected from manufactures catalogues according to required specifications.

4. Return to service refrigerant flow control

4.1. System is evacuated and recharged with refrigerant safely, in accordance with refrigeration principles and procedures and relevant standards and codes.

4.2. System is leak tested in accordance with refrigeration principles/procedures and relevant standards and codes.

4.3. Flow control is adjusted to manufactures' specifications in accordance with refrigeration principles and procedures and relevant standards and codes.

4.4. Performance check is undertaken in accordance with refrigeration principles and procedures and relevant standards and codes.

4.5. Maintenance records service reports are completed by appropriate designated means.

REQUIRED SKILLS AND KNOWLEDGE 

This section describes the skills and knowledge required for this unit.

Required skills 

Look for evidence that confirms skills in:

• using tools, techniques and equipment necessary to check for correct operation
• obtaining and interpreting specifications
• comparing system and component performance/operation against specification
• select replacement controls and/or components
• identifying faulty components and non-compliances
• using appropriate test equipment to identify non-compliance
• safely remove, contain or add refrigerant to relevant Australian standards or codes
• making required adjustments to achieve specifications
• sourcing and using relevant catalogues/lists
• applying safety procedures, standard operating procedures and legislative requirements to all work undertaken
• documenting results of the adjustments

Required knowledge 

Look for evidence that confirms knowledge of:

• operation of refrigerant flow controls including:

• TEV
• internal equalised
• external equalised
• direct operating
• servo operated
• pilot operated

• MOP
• cross charged
• gas charged
• capillary tube
• thermo electric
• electronic TEV and controllers
• low side floats
• high side floats
• distributors
• reversing valves
• solenoid valves
• non return valves
• EPR
• CPR
• condenser bypass valves
• liquid level controllers
• AX valves
• hand expansion valves
• measuring instruments/equipment, specifications and procedures for checking temperature(s)
• measuring instruments/equipment, specifications and procedures for checking components
• procedures for reporting non-conformances
• procedures and sequence for performing preventative maintenance
• specifications, operational characteristics and process for identifying system components
• process for localising and confirming faulty components
• process for identifying refrigerant type
• procedures and all legislative and regulatory requirements for safely removing the refrigerant and charging the system
• procedures for dismantling, repairing, reassembling and testing components
• procedures for selecting replacement parts
• procedures for completing maintenance records/service reports

EVIDENCE GUIDE 

The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment 

A person who demonstrates competency in this unit must be able to maintain, adjust, repair or replace refrigerant flow controls, either liquid or vapour, to manufactures' specifications safely to relevant Australian standards codes and regulations. Competency in this unit cannot be claimed until all prerequisites have been satisfied.

Critical aspects for assessment and evidence required to demonstrate competency in this unit 

Assessors must be satisfied that the candidate can competently and consistently perform all elements of the unit as specified by the criteria, including required knowledge, and be capable of applying the competency in new and different situations and contexts.

Context of and specific resources for assessment 

This unit may be assessed on the job, off the job or a combination of both. Where assessment occurs off the job, i.e. the candidate is not in productive work, an appropriate simulation must be used where the range of conditions reflects realistic workplace situations. The competencies covered by this unit would be demonstrated by an individual working alone or as part of a team. The assessment environment should not disadvantage the candidate.

This unit could be assessed in conjunction with any other units addressing the safety, quality, communication, materials handling, recording and reporting associated with the maintenance, repair/replacement or adjustment of refrigerant flow controls, or other units requiring the exercise of the skills and knowledge covered by this unit.

Method of assessment 

Assessors should gather a range of evidence that is valid, sufficient, current and authentic. Evidence can be gathered through a variety of ways including direct observation, supervisor's reports, project work, samples and questioning. Questioning techniques should not require language, literacy and numeracy skills beyond those required in this unit of competency. The candidate must have access to all tools, equipment, materials and documentation required. The candidate must be permitted to refer to any relevant workplace procedures, product and manufacturing specifications, codes, standards, manuals and reference materials.

Guidance information for assessment 

RANGE STATEMENT 

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Control 

Selected from required knowledge list

Parameters 

Operational values

Refrigerant control 

Could be any selected from list in required knowledge

Characteristics 

Operational parameters of the flow control

Associated valves 

Check valves, solenoid valves

Test equipment 

Refrigeration gauges, thermometers, multimeter, vacuum pump, leak detector, associated hand tools, specialised hand tools

Components 

Any part of any flow control selected from list in required knowledge

Performance 

Pressures, temperatures and relationships

Unit sector 

Co-requisite units 

Competency field 

Maintenance and diagnostics