TWC Services, Inc. Structured On-The-Job Training for JT- 1, 2, 3 The following tasks parallel the Jr. Tech (JT-1, 2, 3) description and development plan and use the Refrigeration and Air conditioning Technologies 8 th edition as a reference. Please refer to this resource for additional information. It s intended that the performance of these tasks be preceded by some type of formal study like local apprenticeship or online training program. It is expected that the technician will seek opportunities and actively work with their manager in completing these tasks. A scheduled monthly meeting with your direct supervisor is recommended to let them know how you are progressing. They are in the best position to help you get the work you need to move forward. To be clear, the Jr. Tech must perform the tasks safely and properly in the presence of a designated witness in order for the validation to be accepted. Receiving physical help is acceptable in cases that require two people to do the work. Both parties (Jr. Tech and ) are responsible for seeing that work is performed safely, and all technicians must follow safe work practices. It is assumed that the person performing these tasks knows how to do them and is capable of doing them in a safe manner. If you do not know how to perform a task safely, do not do it. Think, Watch, Control Tools and Equipment Date Required Tool Inventory 1) Basic hand tools (Attach tool inventory) 2) VOM (See specs. on tool list) 3) Refrigeration Gauges (STM must verify accuracy) Heat and Temperature Measuring temperatures 4) Using the ice bath method, verify probe accuracy 5) Measure DB (Dry Bulb) air temperature 6) Measure WB (Wet Bulb) air temperature 7) Measure surface temperature 8) Measure liquid temperature Basic Electricity- Discuss safe work procedures and PPE before proceeding Understand Ohms law and its application in our industry 9) Use VOM to check resistance of contactor coil 10) Use VOM to check continuity of thermostat wire 11) Use VOM to check analog sensor 12) Use VOM to check binary contacts 2601 Bell Avenue Des Moines, Iowa / 50312 515.284.1911 www.twcservices.com
Measure AC and DC volts, mili-volts, AC amps, DC micro-amps, continuity, and resistance to 100K 13) Use VOM to measure A/C supply voltage @ disconnect 14) Use VOM to verify the voltage from the disconnect 15) Using the data from the task above, calculate any voltage drop from the disconnect to the compressor terminals 16) Use VOM to measure DC voltage 17) Describe where this DC voltage was located in the circuit. 18) Use VOM to measure mili-volts on a thermocouple 19) Use VOM to measure mili-volts on a thermopile 20) Use VOM to measure amps on a single phase circuit 21) Use VOM to measure amps on a 3-Phase circuit 22) Calculate the phase balance of a three phase circuit 23) Use VOM to measure micro-amps on flame rectification circuit 24) Measure the temperature and resistance of a thermistor and compare the reading to the manufactures data. Identify capacitor types and values, understand how they function in the system, and be able to read their MFD value. 25) Measure MFD value of a run capacitor 26) Explain if the capacitor reading is in an acceptable range 27) Measure the MFD value of a start capacitor 28) Using two 10 MFD capacitors, configure them to achieve 5 MFD. 29) Using two 5 MFD capacitors, configure them to achieve 10 MFD. Identify switches, relays, and electrical components, and be able to verify their proper operation. 30) Identify compressor contactor and explain its operation 31) Identify potential relay and verify its operation 32) Identify high pressure control, explain what it s used 33) Identify fan relay and certify proper operation 34) Identify low pressure control and verify its proper operation 35) Identify liquid line solenoid and verify its proper operation Have knowledge of wire types and sizing for high and low voltage 36) Visually Identify wire size in disconnect 170509 Page 2
Have knowledge of different fuse types and replacement procedures 37) Identify bad fuse with VOM 38) Change high voltage fuse 39) Change low voltage fuse Identify LV transformer and verify that it s applied and operating properly. 40) Measure and record primary voltage 41) Measure and record secondary voltage 42) Measure current as different components are energized. 43) Install replacement multi-tap LV transformer Know how to make high and low voltage wiring repairs. Understanding of when and how to use wire nuts, crimp fitting, lug nuts or terminal blocks for high and low voltage wire. 44) Use wire nut to connect LV Wires 45) Use wire nut to connect HV wire 46) Strip wire and connect to HV terminal block 47) Strip wire and connect crimp fitting Be able to properly install or repair seal-tight connection 48) Repair or install seal tight connection Pressurization, Leak Testing, Evacuation Discuss safe work procedures and PPE before proceeding 49) Install nitrogen pressure regulator on tank 50) Pressurize empty system with Nitrogen 51) Evaluate standing pressure for leak 52) Check for leaks using soap solution 53) Pressurize system or component with nitrogen and trace gas 54) Check for leak with electronic leak detector 55) Purge nitrogen and or trace gas from system 56) Evacuate system to 500 microns and hold standing vacuum for 1 minute Refrigeration and Refrigerants Basic understanding of the refrigerant circuit- 57) Describe and Identify the 4 major components of a refrigeration circuit 170509 Page 3
58) Describe and identify (in a working systems) the 3 major metering devices 59) Name the 5 different types of commonly used compressors 60) Identify 2 different compressor types in working systems 61) Identify a liquid line solenoid and describe its operation 62) Explain how refrigerant pump-down is accomplished 63) Explain the difference between pump-down and shut-down 64) Identify and describe the operation of a switch-over or reversing valve 65) Identify and describe the operation of a head pressure control valve 66) Connect gauges and read refrigerant pressures and temperatures. 67) Take readings and calculate superheat 68) Take readings and calculate sub-cooling 69) Verify proper refrigerant charge for split system with TXV Discuss readings with STM, and determine if the readings are appropriate for the metering device being evaluated. 70) Verify proper refrigerant charge for split system with fixed orifice Discuss readings with STM, and determine if the readings are appropriate for the metering device being evaluated. 71) Identify and explain operation of low-pressure control 72) Set low-pressure control for temperature control 73) Set low pressure control for pump down control 74) Add refrigerant to a system 75) Remove refrigerant from a system. 76) Perform weigh-in charging procedure 77) Identify components of a basic heat pump circuit and Explain what type of defrost is being used 78) Identify components of a basic walk-in cooler circuit and Explain the type of defrost is being used and 79) Identify components of a basic walk-in freezer circuit Explain the type of defrost is being used and Discuss appropriate defrost frequency for system above 170509 Page 4
Basic understanding of residential / light commercial HVAC systems- 80) Explain proper air flow in CFM per ton of air conditioning 81) Measure and record external static pressure and determine if it s within range for the air moving system being used 82) Measure relative humidity 83) Explain if humidity level is in an acceptable range for cooling 84) Identify kitchen exhaust fan and check for proper operation 85) Be familiar with duct systems and air flow. 86) Be capable of making minor duct repairs and modifications Combustion systems- Review safe work practices and PPE before proceeding 87) Identify gas system components and give brief description 88) Identify gas type for the system being checked 89) Explain the flame safety for the system being checked 90) Visually inspect flame and explain condition 91) Measure inlet gas pressure 92) Measure manifold gas pressure 93) Measure milli-volts in working system 94) Measure micro-amps in a working system 95) Inspect venting and confirm proper operation Ice Machines- 96) Recite sequence of operation for a Manitowoc ID 302A ice machine 97) Recite sequence of operation for a Hoshizaki KM 201BAH 98) Identify components and give brief description of operation 99) Perform maintenance, clean, and sanitize, Manitowoc 100) Perform maintenance, clean, and sanitize, Hoshizaki 101) Perform maintenance, clean, and sanitize, Follett 102) Identify bin level control and explain operation Thermostats- gas operated, mercury, and electronic 103) Explain basic low voltage thermostat operation 104) Identify proper thermostat location 105) Perform thermostat installation 106) Program 7 day schedule 107) Explain standard set points for heating and cooling 108) Define appropriate high and low limit settings and explain why they are important 109) Verify proper operation and calibration of walk-in Cooler or freezer thermostat 170509 Page 5
Copper Tubing Date 110) Cut copper tubing with pipe cutter 111) Ream copper tubing 112) Swag copper tubing 113) Flare copper tubing 114) Bend copper tubing Brazing and Torch Operation Explain safe and proper operation before proceeding 115) Install gauges on oxygen and acetylene tanks 116) Turn tanks on 117) Set Oxygen and Acetylene pressure regulators 118) Light Oxygen and Acetylene torch 119) Adjust flame for brazing 120) Turn torch off and configure torch kit for transport 121) Identify proper brazing components for all copper 122) Braze all copper connection horizontal 123) Braze all copper connection vertical 124) Identify proper brazing components for brazing copper to steal 125) Identify proper brazing components for brazing copper to brass 126) Braze copper to steal or copper to brass connection. Electric Motors 127) Identify PSC Motor 128) Identify shaded Pole motor 129) Identify ECM motor 130) Identify 3-Phase Motor 131) Identify and explain operation of motor starter 132) Identify and confirm potential relay operation 133) Identify and confirm current relay operation 134) Identify and explain how a PTCR (Positive Temperature Coefficient Resistor) works HVAC-R Maintenance TWC Maintenance levels 1-3 135) Describe TWC Maintenance Levels 136) Perform all TWC Maintenance levels Coil and Drain Cleaning 137) Clean a walk-in evap. coil 138) Clean Drain on AC split system 139) Clean reach in cooler/freezer condenser 170509 Page 6
140) Clean rooftop condenser coil Filter Service 141) Change air filter on rooftop package 142) Change air filter on commercial A/H Refrigeration and electrical components 143) Inspect components and identify defective parts 144) Review common service related failures found 145) during a maintenance 146) Review the final task on every level notify the 147) manager of all issues Heating system components 148) Clean pilot assembly 149) Clean and inspect burner assembly on a gas furnace 150) Inspect gas valve and check gas pressure 151) Test high limit 152) Inspect gas valve and check gas pressure 153) Inspect heat exchanger 154) Inspect and clean electric heat element Blower drive components 155) Inspect and change belt if needed 156) Adjust belt tension 157) Inspect drive and driven pulleys 158) Grease bearing 159) Clean blower wheel Duct System 160) Measure external static pressure Discuss if the reading is in range or if indicates the need for further inspection. Date of Completion- Manager- STM- 170509 Page 7