Jr. Tech (JT-1, 2, 3) Knowledge Areas The Jr. Tech Level includes technicians that are just entering the business and are in the beginning stages of their HVAC-R training and development. Over this period of time, it is expected that the Jr. Tech would learn or acquire: Fundamentals of the Industry Required Tools Basic HVAC-R Tasks Routine Maintenance TWC Services, Inc. is committed to the career development of all of its employees, and it is because of this commitment that an expectation of continual training and development must be understood by all. For the Jr. Tech, enrollment in apprenticeship, vo-tech or online training courses is highly recommended. A description of the Jr. Tech level and expectations for required learning are provided below. The following areas of knowledge and list of skills have been assembled in parallel with Refrigeration and Air Conditioning Technology, 8 th edition. Please refer to this publication for additional information. Fundamental Trade Knowledge Heat Heat, Temperature, BTU Thermodynamic Laws Conduction, Convection, Radiation Sensible and Latent Heat Specific Heat Reference- Section 1, Unit 1.1 thru 1.9 Pressure Atmospheric Pressure, Barometric Pressure Gauge Pressure Reference Section 1, Unit 1.11 thru 1.13 2601 Bell Avenue Des Moines, Iowa / 50312 515.284.1911 www.twcservices.com
Matter Elements and Compounds States of Matter Mass and Weight Density Specific Gravity Specific Volume Gas Laws Boyle s Law, Charles s Law, Dalton s Law Reference Section 1, Unit 2.1 thru 2.6 Energy Energy Heat Energy Conservation of Energy Energy in Magnetism Work, Power Electrical Power- Watts Reference Section 1, Unit 2.7 thru 2.14 Refrigeration and Refrigerants Basic Refrigeration Cycle BTU / BTUH / Capacity / Tons of refrigeration Refrigerant Pressure and Temperature Properties of Refrigerant Basic Refrigerant Cycle Components Refrigerants Reference- Section 1, Units 3.1 thru 3.18 Safety Pressure Vessels and Piping Electrical Hazards Fire Ladder Use Hot and Cold Surfaces, Gases, and liquids Mechanical Equipment Heavy Objects Refrigerants Confined Spaces 2
Chemicals Reference- Section 2, Units 4.1 thru 4.8 Tools and Equipment Basic Hand tools Tubing and Piping Types and Sizes Tubing Insulation Line Sets Cutting Tubing Bending Tubing Brazing and Soldering Heat Sources for Brazing and Soldering Flaring Procedures Soft Copper Swaging Steel Pipe- cutting, threading PVC Pipe assembly Other- crimped fittings, push on fittings, flexible gas lines Reference- Section 2, Units 5.1 thru 7.19 Basic Leak Testing Pressurization Purging System Evacuation Reference- Section 2, Units 8.1 thru 8.8 Basic Electricity and Magnetism Atom- components and structure Electrons Conductors Insulators Electricity from Magnetism Alternating and Direct Current (AC/DC) Volts, Amps, and Ohms Electrical Power Generation Basic Electrical Circuit Ohm s Law Electrical Symbols Series and Parallel Circuits 3
Magnetism Inductance Capacitance Impedance Transformers Electric Test Meters Electrical Circuit Protection Fuses, Circuit Breakers, and GFI Semiconductors Diodes, Rectifiers, Thermistors Reference- Section 3, Units 12.1 thru 12.23 Automatic Controls, Components, and Applications, Electromechanical and DDC Types of Automatic Controls Thermal Controls Bi-Metal Fluid Filled Thermocouple / Thermopile Thermistors (PTC and NTC) Reference- Section 3, Units 13.1 thru 13.6 Electric Motors Motor Design, Construction, and Operation Motor Types- Shaded Pole, PSC, ECM, VFD Three Phase Motors Motor Relays and Controls Potential Relays Current Relays PTCR (Positive Temperature Coefficient Resistor) Basic VFD (Variable Frequency Drive) operation Reference- Section 4, Units 17.1 thru 17.3 Application of Motors Power Supply Voltage Current Electrical Frequency and Phase Working Conditions Insulation Type and Class 4
Bearing Types Mounting Drive Assemblies Reference- Section 4, Units 18.1 thru 18.7 Motor Controls Relays, Contactors, Starters Overload Protection NEC Standards Temperature Sensors Reference- Section 4, Units 19.1 thru 19.12 Refrigeration System Operation Evaporator Condenser Compressor Metering Device Reference- Section 5, Units 20 thru 24 Basic Ice Machine Operation and Maintenance Machine Types Water systems Refrigeration Circuits Controls and Microprocessors Water Quality and Filtration Maintenance and Cleaning Reference- Section 5, Units 27.1 thru 27.8 Heating Systems & IAQ Electric Heat 30.1 thru 30.17 Gas Heat 31.1 thru 31.30 Condensing and Non-Condensing Systems Burner types Exhaust Gas Venting Gas Types Ignition systems Flame Proving Systems Gas Piping Gas Delivery and Pressure Ranges 5
IAQ (Indoor Air Quality) 34.1 thru 34.12 Reference- Section 6, Units 30.1, 31, and 34 Air Conditioning Indoor Comfort Basic Psychrometrics Air Flow Installation Reference- Section 7, Units Heat Pumps Reverse Cycle Refrigeration System Coefficient of performance Sequence of operation Balance point Auxiliary heat function Types of defrost Dual fuel sequence of operation Component identification Thermostat Control Reference- Section 8, Unit 43 Commercial Rooftops Installation Curbs Cranes and Rigging Economizers Reference- Section 10, Unit 50 HVAC-R Maintenance Coil and Drain Cleaning Determining the proper cleaning method Selecting the proper cleaning solution Mixing the cleaning chemicals Cleaning fluid containment Drain cleaning and treatment Drain trap design and construction Filter Service 6
Filter types and selection Filter changes System and Component Inspection and Testing Electrical components and wiring High voltage connections Low voltage connections Refrigeration components Mechanical components Motors, belts, pulleys, bearings, dampers Heating system components Pilot assemblies Ignition systems Gas valves Combustion fans and venting Heat exchangers Thermostats and Controls 7