Back to Critical Work Functions Click here for AEKS Matrix
Occupational Title: Heavy Equipment Maintenance Technician
Key Purpose: Diagnose, service and repair heavy equipment
Critical Work Function
7 Diagnose, service, and repair vehicle refrigerant control systems 		Occupational Skills, Knowledge and Conditions
Key Activities
Performance Criteria
Occupational Skills and Knowledge
Conditions
Those duties or task clusters that are necessary to perform each critical work function.
Specific demonstrable performance and standards that indicate when the key activity has been performed successfully.
Those skills and knowledge that are specific to the occupation, such as technical processes or procedures common across the occupation that are critical to the related key activity.
Tools, resources and equipment necessary to carry out key activities and their related performance criteria.




 KA
  7.1 		Diagnose, service, and repair air conditioning system.
Number
Criteria
7.1.1 Perform air conditioning operational and performance checks.
7.1.2 Determine the type of refrigerant and amount of charge required.
7.1.3 Remove and replace air conditioning refrigerant.
7.1.4 Flush air conditioning system.
7.1.5 Check compressor oil level and add oil to system.
7.1.6 Check heater water valve for proper operation.
7.1.7 Perform voltage-drop checks on air-conditioning clutch circuit.
7.1.8 Test, remove, and install/replace air conditioning components and parts.
7.1.9 Post-service performance indicates components performing at or above OEM specifications.
Knowledge of air-conditioning system components, parts, and their function

Knowledge of various types of refrigerants

Understanding of physical, mechanical, and chemical principles of refrigeration

Knowledge of and application of appropriate test gauges and measuring instruments

Knowledge of proper air conditioning maintenance procedures (recycling refrigerant, evacuating system, usage of gauges, check for bubbles, check temperature/pressure, and check blower)

Knowledge and ability to read electrical schematics

Knowledge and usage of shop manuals and other appropriate documentation
Using the following tools, resources, and equipment:

Common mechanic's hand tools

Manifold test gage set (R134A/R12)

Thermometer

Flush kit

UL/SAE-certified recycling/recharging unit

Appropriate shop service tools and testing equipment

Appropriate shop service manuals and other documentation

KA   7.2 Diagnose, service, and repair transport refrigeration systems.
Number
Criteria
7.2.1 Check refrigeration system's operation and performance.
7.2.2 Determine the type of refrigerant used in the unit and the amount of charge required.
7.2.3 Remove and replace refrigeration system refrigerant.
7.2.4 Perform pressure and leak tests on the refrigeration unit and determine needed repairs.
7.2.5 Perform electrical system test on the refrigeration unit and determine needed repairs.
7.2.6 Perform manufacturer's required maintenance on refrigeration unit.
7.2.7 Test, remove, install/replace, and adjust refrigeration system parts and components.
7.2.8 Remove and install/replace refrigeration unit.
7.2.9 Post-service performance indicates that components performing at or above OEM specifications.
Knowledge of transport refrigeration components and parts, and their function

Knowledge of various types of transport refrigeration systems

Knowledge of various types of refrigerants used in transport refrigeration systems

Knowledge and application of various test gauge sets and measuring instruments

Knowledge and ability to read schematics

Understanding of proper refrigeration system maintenance (evacuating, dehydrating, charging, and adjusting)

Knowledge and usage of shop manuals and other appropriate documentation
Using the following tools, resources, and equipment:

Common mechanic's hand tools

Manifold test gauge set (R134A/R12)

Thermometer

UL/SAE-certified recycling/recharging unit

Appropriate service tools and testing equipment

Belt tension gauge

Flush kit

Appropriate shop service manuals and other documentation