NZQA Expiring unit standard
Title
22704 version 2
Page 1 of 8
Maintain and service refrigeration and air conditioning systems
Level
Purpose
3 Credits 20
This unit standard is for people who work, or intend to work, in the refrigeration and air conditioning sector of the engineering industry, and is intended for use in the training of maintenance and service personnel for refrigeration and air conditioning equipment.
People credited with this unit standard are able to, for refrigeration and air conditioning systems: demonstrate knowledge of the benefits of, and procedures for, performing routine maintenance procedures; source, interpret, and apply information to maintenance and servicing procedures; maintain the integrity of lubrication and refrigerant systems, secondary heat transfer mediums, and air distribution systems; maintain the integrity of mechanical components, thermal insulation, heat transfer componentry, and defrost and/or de-ice systems, and condensate drainage; calibrate and test control and reporting systems; check and maintain electrical components; diagnose and rectify faults; retrofit existing systems with alternative refrigerants; recondition components; and initiate follow-up actions, verify that system specifications have been met, and complete documentation.
Classification Mechanical Engineering > Refrigeration and Air Conditioning
Available grade
This unit standard is expiring
Entry information
Recommended skills and knowledge
Competenz
SSB Code 101571
Recommended: Unit 22706, Assemble commercial refrigeration and/or air conditioning system components under supervision , or demonstrate equivalent knowledge and skills.
Explanatory notes
1 References
Building Act 2004;
Electricity Act 1992;
Electricity Amendment Act 1997;
Hazardous Substances and New Organisms Act 1996;
Health and Safety in Employment Act 1992;
Ozone Layer Protection Act 1996;
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This unit standard is expiring
New Zealand Qualifications Aut

NZQA Expiring unit standard 22704 version 2
Page 2 of 8
Electricity Regulations 1997;
AS/NZS 1677:1998, Refrigerating systems – Refrigerant classification ;
AS/NZS 3000:2000, Electrical installations ;
Code of Practice for the reduction of emissions of fluorocarbon refrigerants in refrigeration and air conditioning applications . Institute of Refrigeration, Heating and
Air Conditioning Engineers of New Zealand (IRHACE New Zealand), 2001. Available from IRHACE, 28 E Lambie Drive, Manukau City, http://www.irhace.org.nz/.
2 Definitions
Commercial refrigeration and air conditioning systems refers to items such as: refrigeration equipment as found in retail food outlets, truck and shipping-container refrigeration, horticultural cool room refrigeration, controlled atmosphere fruit stores; and packaged or split air conditioning equipment as found in commercial buildings and computer rooms.
Industrial refrigeration and air conditioning systems refers to single or multi-staged refrigeration and air conditioning systems (typically using ammonia refrigerant) used in the manufacturing process in areas such as freezing works, breweries, and chemical plants.
Maintenance and servicing activities may include but are not limited to the use of advanced techniques such as: vibration analysis, thermography, trend analysis, laser alignment, refractometry.
Organisational procedures refer to documents that include: organisational rules, codes, and practices; equipment operating instructions; production specifications; documented quality management systems; and health and safety requirements.
3 Range
Competence is to be displayed on either commercial or industrial refrigeration and air conditioning systems .
Outcome 1 This unit standard is
Demonstrate knowledge of the benefits of, and procedures for, performing routine expiring
Evidence requirements
1.1 Consequences of inadequate maintenance of cooling towers and/or evaporator condensers are described in terms of potential health risks and their associated symptoms for persons living or working on-site.
Range health risks may include but are not limited to
– distribution of infected aerosols, establishment of sites of inhalation and infection risk, multiplication factors.
1.2 Procedures for ensuring that routine maintenance of refrigeration and air conditioning systems minimises health risks for persons living or working on-site are described in terms of maintenance activities, tests, and frequency of tests.
Range systems – cooling towers, air-cooled condensers, water-cooled condensers, evaporative condensers, evaporators, evaporative
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New Zealand Qualifications Authority 2020 Competenz
SSB Code 101571
This unit standard is expiring
New Zealand Qualifications Aut

NZQA Expiring unit standard 22704 version 2
Page 3 of 8 coolers, drain trays and drains, automatic dosing systems for scale, corrosion, and biocides; maintenance activities may include but are not limited to – use of biocides; cleaning, disinfection, pre-chlorination; disassembly, cleaning, and reassembly of components; post-chlorination; total dissolved solids (TDS) bleed off; tests may include but are not limited to
– bacterial, legionella, pH, total alkalinity, free chlorine; frequency of tests may include but is not limited to – weekly, monthly, half-yearly.
Outcome 2
Source, interpret, and apply information to maintenance and servicing procedures for refrigeration and air conditioning systems.
Evidence requirements
2.1 Componentry is identified and layout of systems is established from site drawings.
2.2 Correct sequence of system operation is determined from wiring diagrams and piping schematics.
2.3 Maintenance schedules are obtained, details of the work to be completed at specified intervals are identified, and verification is sought as to their suitability to meet operational requirements.
2.4
2.5
Maintenance schedules are followed to meet operational requirements.
Follow-up actions which are required to maintain the integrity of systems are
2.6 reported in accordance with organisational procedures. This unit standard is
Procedures are implemented to protect personnel, equipment, and property in
Range expiring may include but is not limited to
– warning notices, identifications, equipment isolation, electrical isolation.
Outcome 3
Maintain the integrity of lubrication systems in refrigeration and air conditioning systems.
Evidence requirements
3.1 Lubrication system variables and components are checked and adjusted as required to meet operational specifications.
3.2 Oil levels and circulation balances are checked and adjusted as required to meet operational specifications.
3.3 Oil leaks are detected and rectified to ensure operational integrity.
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New Zealand Qualifications Authority 2020 Competenz
SSB Code 101571
This unit standard is expiring
New Zealand Qualifications Aut

NZQA Expiring unit standard
3.4
22704 version 2
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Oil properties and conditions are tested and adjusted as required to meet operational specifications.
Outcome 4
Maintain the integrity of refrigerant systems in refrigeration and air conditioning systems.
Evidence requirements
4.1 Pressure drops across strainers, filters, and filter driers are checked and recorded.
4.2
4.3
Refrigerant leaks are detected and rectified to ensure operational integrity.
Refrigerant system variables are checked and adjusted as required to meet operational specifications.
4.4
4.5
System contaminants are detected and removed to ensure operational integrity.
Where connected, automatic air purgers are checked and adjusted as required to meet operational specifications.
4.6 Where automatic air purgers are not connected, an appropriate manual method is used to diagnose non-condensable gases.
4.7 Where connected, safety relief valves are checked and maintained in accordance with operational specifications.
Outcome 5
Maintain the integrity of secondary heat transfer mediums and air distribution systems in This unit standard is
Evidence requirements
5.1 expiring
Evaporator or indoor air distribution system components and airflows are checked and maintained to meet operational requirements.
5.2 Condenser or outdoor air distribution systems are checked and maintained to meet operational requirements.
5.3 Heat exchangers, their associated pipe-work, and internal fluids are checked and maintained to meet operational requirements.
Range heat exchangers include any of – evaporative condenser, dry cooler, other finned heat exchanger.
5.4 Where fitted, fire damper operation is checked and adjusted as necessary to meet operational requirements.
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New Zealand Qualifications Authority 2020 Competenz
SSB Code 101571
This unit standard is expiring
New Zealand Qualifications Aut

NZQA Expiring unit standard
5.5
22704 version 2
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Where fitted, humidity plant is checked, serviced, and sanitised to meet operational requirements.
5.6 Condensate pans and drains are checked, cleaned, and sanitised to meet operational requirements.
5.7 Where fitted, air filtration equipment is checked, cleaned, and sanitised to meet operational requirements.
5.8 Coil faces, fixings, connections, and any ducting are checked, cleaned, sanitised, and de-iced as required to meet operational requirements.
Outcome 6
Maintain the integrity of mechanical components, thermal insulation, heat transfer componentry, and defrost and/or de-ice systems, and condensate drainage in refrigeration and air conditioning systems.
Evidence requirements
6.1 Where fitted, duct-attached access doors, safety guards, fans, pumps, compressors, hoses, supports, structures, seismic restraints, and/or enclosures are checked and maintained to meet operational requirements.
6.2 Insulation and vapour barrier integrity is checked and maintained to meet operational requirements.
Range may include but is not limited to – piping, ducting, pressure vessels, cool-room panels.
6.3 Where fitted, cool-room doors, door hinges, door safety release mechanisms, bi-flow relief ports, and/or door curtains are checked and maintained to meet This unit standard is
6.4 expiring
6.5 Where fitted, heat exchanger protections such as surface coatings or sacrificial anodes are checked and maintained to meet operational requirements.
6.6 Defrost and/or de-ice systems are maintained and adjusted as required to meet operational requirements.
Range systems may include but are not limited to
– electrical, hot gas, air, reverse cycle, water.
Outcome 7
Calibrate and test control and reporting systems in refrigeration and air conditioning systems.
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New Zealand Qualifications Authority 2020 Competenz
SSB Code 101571
This unit standard is expiring
New Zealand Qualifications Aut

NZQA Expiring unit standard
Evidence requirements
22704 version 2
Page 6 of 8
7.1 The operation of controls is checked and controls are adjusted as required to meet operational specifications.
7.2 Monitors and reporting systems are checked, and recalibrated or adjusted as required to meet operational specifications.
Outcome 8
Check and maintain electrical components in refrigeration and air conditioning systems.
Evidence requirements
8.1 Electrical circuits are tested, and currents, voltages, and insulation resistances are measured and recorded.
8.2 Test and measurement results are compared with standards and/or ratings, and faults are identified.
8.3 Power train equipment is checked and maintained to meet operational requirements.
Range may include but is not limited to – switches, fuses, contactors, relays, timers, overloads, soft-starts, variable speed drives
(VSDs), microprocessors, data loggers.
Outcome 9
Diagnose and rectify faults in refrigeration and air conditioning systems.
Evidence requirements This unit standard is
9.1 Faults are identified and diagnosed through information provided by users
9.2 expiring
Faults are identified and diagnosed through electrical test procedures.
Range may include but is not limited to – electrical circuit’s continuity and mode, conductor and insulation resistance, componentry integrity, voltages, current draw, phase sequence, termination tightness.
9.3 Faults are identified and diagnosed through engineering data.
Range engineering data may include but is not limited to – pressure variances, temperature variances, superheats, sub-cooling, humidity levels, air flows, fluid flows, carbon dioxide levels.
9.4 Faults are rectified in accordance with organisational procedures.
Range may include but is not limited to – pump-down, recovery, evacuation.

New Zealand Qualifications Authority 2020 Competenz
SSB Code 101571
This unit standard is expiring
New Zealand Qualifications Aut

NZQA Expiring unit standard 22704 version 2
Page 7 of 8
Outcome 10
Retrofit existing refrigeration and air conditioning systems with alternative refrigerants.
Evidence requirements
10.1 Suitability of equipment for retrofit is investigated and justified in terms of lifecycle cost and industry practice.
10.2 Alternative refrigerants and their appropriate oils are selected and inserted into existing systems in accordance with organisational procedures.
Outcome 11
Recondition components for refrigeration and air conditioning systems.
Evidence requirements
11.1 Refrigeration and air conditioning components are reconditioned and overhauled in accordance with organisational procedures.
Range may include but is not limited to – compressor, pump, fan, motor, valve; evidence of two components is required.
Outcome 12
Initiate follow-up actions, verify that system specifications have been met, and complete documentation for refrigeration and air conditioning systems.
Evidence requirements This unit standard is
12.1 Requests and work orders for required follow-up actions are prepared in
12.2 expiring
Relocated, repaired, and/or converted equipment, components, and/or subsystems are reassembled, tested and/or recommissioned to meet system specifications.
12.3 Documentation detailing maintenance and servicing activities completed is recorded in accordance with organisational procedures.
Range documentation may include but is not limited to
– logbooks, service sheets, building management system (BMS) logs, purchase orders, recommissioning verification, warranty; details may include but are not limited to
– labour inputs, materials, operating conditions, adjustments made.
12.4 Manuals and/or operating instructions are updated as necessary to match current specifications.
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New Zealand Qualifications Authority 2020 Competenz
SSB Code 101571
This unit standard is expiring
New Zealand Qualifications Aut

NZQA Expiring unit standard
12.5
22704 version 2
Page 8 of 8
Changes in plant characteristics, operational requirements, and/or regulatory requirements affecting maintenance schedules and/or other system description documentation are identified and reported in accordance with organisational procedures.
Replacement information This unit standard has been replaced by unit standards
28960 and 28965.
This unit standard is expiring. Assessment against the standard must take place by the last date for assessment set out below.
Status information and last date for assessment for superseded versions
Process Version Date Last Date for Assessment
Registration 1 20 June 2006 31 December 2019
Review 2 18 June 2015
Consent and Moderation Requirements (CMR) reference
31 December 2019
0013
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do
.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
This unit standard is which are assessing against unit standards must engage with the moderation system that applies to those standards. expiring
Requirements for consent to assess and an outline of the moderation system that applies to this standard are outlined in the Consent and Moderation Requirements (CMR). The
CMR also includes useful information about special requirements for organisations wishing to develop education and training programmes, such as minimum qualifications for tutors and assessors, and special resource requirements.
This unit standard is expiring

New Zealand Qualifications Authority 2020 Competenz
SSB Code 101571
New Zealand Qualifications Aut