NZQA Expiring unit standard 3397 version 4 Page 1 of 5. Convert an automotive air conditioning system from R-12 to R-134a

Transcription

1 Page 1 of 5 Title Convert an automotive air conditioning system from R-12 to R-134a Level 3 Credits 2 Purpose This unit standard is for people in the automotive repair industry. People credited with this unit standard are able to: evaluate condition of existing air conditioning system on a vehicle; prepare air conditioning system for retrofitting; convert an air conditioning system for R-134a operation; and test R- 134a air conditioning system operation. Classification Motor Industry > Automotive Heating, Ventilation, and Air Conditioning Available grade Achieved Guidance Information 1 Legislation and publications relevant to this unit standard include but are not limited to Health and Safety in Employment Act 1992; Ozone Layer Protection Act 1996; Society of Automotive Engineers (SAE) recommended practices as described in J639 Safety Standards for Motor Vehicle Refrigerant Vapor Compressions Systems, 2005; J1660 Fittings and Labels for Retrofit of Cfc-12 (R-12) Mobile Air-Conditioning Systems to HFC-134a (R-134a), 1998; and J1661 Procedure Retrofitting CFC-12 (R- 12) Mobile Air-Conditioning Systems to HFC-134a (R-134a), 1998; Motor Trade Association (MTA) Automotive Air Conditioning Code of Practice; vehicle manufacturer published retrofit procedures. 2 Society of Automotive Engineers Standards are available online at MTA Automotive Air Conditioning Code of Practice is available from the Motor Trade Association, PO Box 9244, Wellington, phone , website 3 Definitions: R-12 refers to Refrigerant 12 known as CFC 12, a chlorofluorocarbon which is a controlled substance within the meaning of the Ozone Layer Protection Act It is used as a refrigerant in automotive air conditioning systems. R-134a refers to Refrigerant 134a known as HFC134a, a hydrofluorocarbon used as a substitute refrigerant for automotive R-12 air conditioning systems and for dedicated systems. Suitable tools and equipment means industry approved tools and equipment that are recognised within the industry as being the most suited to complete the task in a professional and competent manner with due regard to safe working practices.

2 Page 2 of 5 4 Recommended entry information: Unit 981, Install an automotive air conditioning system. Outcomes and performance criteria Outcome 1 Evaluate condition of existing air conditioning system on a vehicle. 1.1 Safe working practices are observed throughout the task in accordance with 1.2 A visual inspection of all air conditioning components is performed as specified by the manufacturer. Any problems are reported to the supervisor. may include but is not limited to damage, lubricant leaks, corrosion, suitability to be converted, condenser change. 1.3 The vehicle's air conditioning system is operated to check that the system performs on R-12 as intended by the manufacturer. Any malfunction is reported to the supervisor. 1.4 A leak test is performed immediately after the air conditioning system has been operating for 10 to 15 minutes using a compatible leak detector. Any leaks found are repaired in accordance with manufacturer specifications. leaks around compressor, hose fittings, evaporator and condenser. Outcome 2 Prepare air conditioning system for retrofitting. 2.1 Safe working practices are observed throughout the task in accordance with 2.2 Suitable tools and equipment are selected and used that enable the system to be prepared for retrofitting. 2.3 Faults identified from a visual inspection and from an operational check are rectified, so that the air conditioning system operates in accordance with manufacturer specifications.

3 Page 3 of The amount of oil in the compressor is optimised by running the R-12 air conditioning system with the blower on high speed. 2.5 All R-12 refrigerant is recovered from the vehicle's air conditioning system using compatible refrigerant recovery and recycling equipment in accordance with legislative requirements and Code of Practice. 2.6 The air conditioning system is evacuated to remove as much R-12 as possible from the residue mineral oil. minimum of 30 minutes, steady vacuum of 450 microns (29 in.) Hg (mercury) unless otherwise specified by the compressor and vehicle manufacturer. 2.7 The mineral oil is removed from the system following compressor and vehicle manufacturer recommendations. may include but is not limited to removing and draining components, flushing using the recommended flushing fluid or system. Outcome 3 Convert an air conditioning system for R-134a operation. 3.1 Safe working practices are observed throughout the task in accordance with 3.2 Suitable tools and equipment are selected and used that enable R-134a compatible components to be installed to compressor and vehicle manufacturer specifications. 3.3 Non-compatible components are replaced following compressor and vehicle manufacturer recommendations. may include but is not limited to seals, O-rings (where disturbed), desiccant, receiver-drier (accumulator-drier), compressor oil. 3.4 R-134a quick connect service ports are installed over the existing R-12 service ports in a manner that prevents the service ports from being easily removed. 3.5 The air conditioning system is evacuated, so that no air and moisture is present in the system, using R-134a compatible servicing equipment following the procedure outlined in the recovery equipment instructions.

4 Page 4 of The specified amount of R-134a compatible oil (Polyalkylene Glycol [PAG oil] or ester oil) is installed following compressor and vehicle manufacturer recommendations and instructions. 3.7 The air conditioning system is charged with R-134a using compatible servicing equipment, following the compressor and vehicle manufacturer guidelines in accordance with legislative requirements and Code of Practice. 3.8 Retrofit labels are installed close to the service ports, clearly noticeable and displaying information relating to the retrofit. name and address of company (or individual) performing retrofit service, date service performed, type and amount of refrigerant, type and amount of lubricant, warning to use only R-134a refrigerant and the specified oil. 3.9 The vehicle is checked to ensure that no existing labels containing R-12 refrigerant information remain on the vehicle. Outcome 4 Test R-134a air conditioning system operation. 4.1 Safe working practices are observed throughout the task in accordance with 4.2 Suitable tools and R-134a compatible equipment are selected and used that enable the system to be tested to compressor and vehicle manufacturer specifications. 4.3 The air conditioning system is checked for leaks by the use of an R-134a leak tester. 4.4 Any leaks located as a result of leak detection tests are sealed in accordance with compressor and vehicle manufacturer instructions. 4.5 The air conditioning system functions within compressor and vehicle manufacturer acceptable limits of temperatures and pressures. This unit standard is expiring. Assessment against the standard must take place by the last date for assessment set out below.

5 Page 5 of 5 Status information and last date for assessment for superseded versions Process Version Date Last Date for Assessment Registration 1 27 February December 2020 Review 2 21 February December 2020 Review 3 25 January December 2020 Review 4 26 April December 2020 Consent and Moderation Requirements (CMR) reference 0014 This CMR can be accessed at