Course Title:
Course Number:

Introduction to the Refrigeration Cycle: Part 2
AC/R-2
  This course is a continuation of Part 1 I Intro. To Refrigeration Cycle, focusing on high temperature applications including: compressors, condensers, evaporators, metering devices, accessory components, compressor capacity controls, balanced system operation, and pressure-temperature charts.
Course Outline: Download/print this course outline
DAY 1 SUBJECT: Introduction to the Troubleshooting Chart and System Operating Components
GOAL: Demonstrate how an entire air condition system is affected by a single problem and how it can be diagnosed by the troubleshooting chart. Show how the TXV and Cap react to over charge and under charge.
OBJECTIVES: Understand the terminology on the troubleshooting char and terminology used in the HVAC/R trade.
Use the chart to diagnose problems in a typical A/C system
What happen to each component under these conditions
Note differences between charging valves and the service valve
SUBJECT CONTENTS: Troubleshooting chart instructions
Terminology used on the chart
Temp changes across an air cool condenser
Temp changes across a DX fan coil
Normal pressure ranges in an A/C system
Sub cooling temp
Superheat temp
Terminology used on components
TXV, captubes
Safety when installing & removing service gauges
Identify different types of refrigerant valves and the use
Use of different thermometers
Review of shop safety
METHODS/
TECHNIQUES:
Handout on troubleshooting chart
Refrigeration & A/C Technology W.J.T.
RESOURCES: Large troubleshooting chart
Ref — trainer
Overhead
System room
EVALUATION: Entrance Exam
Give superheat reading for given problem
Give subcool reading for given problem
Get temperature difference across the air evaporator
Get temperature difference across air cooler condenser
   
DAY 2 SUBJECT: The Troubleshooting Chart And System Operating Components — Pressure Relief Devices
GOAL: Demonstrate how system performance is affected by poor air flow and to use dye.
OBJECTIVES: To use troubleshooting chart to diagnose different mechanical problems
Understand that troubleshooting chart is a tool for learning to diagnose A/C system problems
To take correct temperature & pressure measurements
To identify different pressure relief devices and how they work
How pressure relief’s are piped in a refrigeration system and why they are needed
SUBJECT CONTENTS: HVAC/R industry terms
Relief devices external
Fusible plug
Spring loaded
Safety reason for relief valves
Solving A/C problems using chart
METHODS/
TECHNIQUES:
Refrigeration & A/C Technology W.J.T.
Troubleshooting charts
Overheads
System room
RESOURCES: Refrigeration & A/C technology W.J.T.
Troubleshooting handouts
Sporlan TXV
Alco TXV
Henry valve
EVALUATION: Homework
Quiz
Solving A/C problem using large troubleshooting chart in front of class
Shop —
  • able to get superheat
  • able to get evap air diff. temp
  • able to get cond. air . diff. temp.
   
DAY 3 SUBJECT: Refrigeration Operating Temperatures And Defrost Systems
GOAL: To identify different refrigeration equipment and temperature ranges. Demonstrate setting up of low pressure temperature control and the operation of different defrost controls
OBJECTIVES: Student will be able to:
Define refrigeration temperature ranges
  1. AC high temperature
  2. Medium temperature
  3. Low temperature
Identify equipment
  1. Low boy box
  2. Reach in box
  3. Walk in box
  4. Ice machine
  5. Heat pump
Discuss/note typical temperatures of evaporators coil temperature to discharge air temperature
  1. Control of temperature
  2. Adjusting of low pressure control
  3. Fin spacing of different coils
Discuss/note different types of defrost: off cycle, radin, plane
  1. Elect
  2. Hot G
  3. Start of defrost clock
  4. Control of evaporator fan
  5. Termination defrost
  6. Clock
  7. Temperature
  8. Pressure
Understand the function of defrost
  1. Ice melting
  2. Returning oil to the compressor
  3. Use on a heat pump
SUBJECT CONTENTS: Trade language
Temperature ranges
Setting of low pressure switcher
Setting of defrost controls
METHODS/
TECHNIQUES:
Classroom handout
Refrigeration & A/C Technology W.J.T.
System room — set up of low pressure control
RESOURCES: Work book/handouts
Refrigeration & A/C Technology W.J.T.
PT. Char — Dupont, sporlan or alco
EVALUATION: Homework
Quiz
Shop performance — set up of pressure control
   
DAY 4 SUBJECT: EPR Control Devices, Refrigerant Migration Protection.
Troubleshooting Chart
GOAL: To understand the EPR valve and how it works with the TXV. To identify the 3 types of refrigerant migration protection strategy and draw an electrical wiring diagram for each.
OBJECTIVES: Student will be able to:
Distinguish between mechanical controls
Explain how an EPR valve functions
Describe electrical controls that apply to refrigerant migration protection
Discuss how poor air or water flow affected a system differently than a dirty condenser
Draw wiring diagram of 3 types of refrigeration migration protection
SUBJECT CONTENTS: Trade terms
EPR control diagrams & installation instruction
Review of TXV operation
METHODS/
TECHNIQUES:
Refrigeration & A/C Technology W.J.T.
Work book handouts
Overheads
Large troubleshooting chart
RESOURCES: Refrigeration & A/C Technology W.J.T.
Sporlan
Alco
Henry
Asco
Dupont — product information
EVALUATION: Shop — show system with pump down
Demonstrate location of EPR valve installation
Demonstrate location of LL Solenoid installation & make wiring diagram
Quiz
   
DAY 5 SUBJECT: Recovery, Evacuation and Leak Checking
GOAL: Demonstrate the use of recovery equipment, vacuum pump & leak checking.
OBJECTIVES: Student will be able to:
Understand the proper procedure to evacuate a refrigeration system
  1. Use of the micron gauge (scale)
  2. Best line size
  3. Heat lamps
Connect a recovery machine
  1. Push pull
  2. Vapor recover
Demonstrate how to leak check:
  1. Standing pressure test
  2. Electronic
  3. Halide leak
  4. Dye — visible & U.V.
  5. Sound ultra sonic
SUBJECT CONTENTS: Trade (terms) language
Safety — precaution when using gauge manifold
Robinair vacuum instructions
Robinair recovery instructions
Hazards of working with halide torch leak detector
METHODS/
TECHNIQUES:
Refrigeration & A/C Technology W.J.T.
Work book handouts
Overheads
RESOURCES: Refrigeration & A/C Technology W.J.T.
Manufacture Instruction & Direction
  1. Vacuum pump
  2. Recovery
EVALUATION: Homework
Quiz
Shop (PBF)
   
DAY 6 SUBJECT: Refrigerant Oils And Safety Controls
GOAL: Demonstrate how an oil pressure works and how it is connected to a compressor. Also how to take net oil pressure on compressors.
OBJECTIVES: Student will be able to:
  • Understand the purpose for refrigerant oil & types
  • Understand net oil pressure reading
  • Demonstrate how an oil pressure safety switch is wired in a circuit
  • Explain the function of an oil pressure switch
SUBJECT CONTENTS: Trade (terms) language
Safety use of tools & equipment
Installation and testing of an oil pressure safety
Operation of an oil pressure safety switch
METHODS/
TECHNIQUES:
Refrigeration & A/C Technology W.J.T.
Work book handouts
Overheads
RESOURCES: Refrigeration & A/C Technology W.J.T.
Penn - Johnson
EVALUATION: PBF
Quiz - written
Homework
   
DAYS 7 & 8 SUBJECT: Auxiliary Components — Their Applications and Operation in the Refrigeration Circuit
GOAL: To identify by shape & location on refrigeration piping the different components & their functions.
OBJECTIVES: Student will be able to point out location for component installation & lines connected to component and it’s purpose.
  1. Liquid line drier & size it
  2. Capillary strainer - drier
  3. Suction accumulator and with heat exchanger
  4. Mufflers — suction & discharge
  5. Receivers
  6. Desuperheatiing heat exchanger
  7. Subcooling heat exchanger
  8. Oil separator
  9. Oil reservoirs
  10. Sight glasses
  11. Vibration
  12. EPR — valve
  13. CPR — valve
  14. Relief valve, plug & disk
  15. Head pressure control
  • Fun Cycle
  • Fan speed
  • Air volume
  1. Flooding condenser controls, oroa valve
  2. Solenoid valve
  3. Pressure switcher
  • Low pressure safety
  • Low pressure control
  • High pressure switch
  • Low ambient control
  • Oil safety switch
SUBJECT CONTENTS: Trade names of components
Trade terms used (language)
Troubleshooting chart; when components are used
Danger when using torch or system with compressed refrigerants
METHODS/
TECHNIQUES:
Refrigeration & A/C Technology W.J.T.
Work book handouts
Overheads
RESOURCES: Refrigeration & A/C Technology W.J.T.
Refrigeration Research Inc.
Alco
Sporlan
Ranco
Penn — Johnson
Large Troubleshooting Chart
EVALUATION: Homework
Quiz
   
DAY 9 SUBJECT: Cooling Towers; Water Supplies & Water Reg Valve
GOAL: Demonstrate simple maintenance service on tower, back flush a condenser and adjust a water valve
OBJECTIVES: Student will be able to:
Discuss/understand the operation of a cooling tower
Identify different types of towers
  1. Forced Air
  2. Natural Draft
Discuss the water supply & treatment for cooling tower
Identify safety conditions when working on indoor & outdoor towers
Discuss adjusting/flushing water valve
SUBJECT CONTENTS: Trade language (terms)
Poor safety attitude
The effect of electrical shock
Danger of flooding space
Freeze up
METHODS/
TECHNIQUES:
Work book handouts
Overheads
PBF in system room
RESOURCES: Marley tower
Metrey
Penn - Johnson
EVALUATION: Homework
Quiz
PBF
   
DAY 10 SUBJECT: Evaporative Condensers, Evaporative Fluid Cooler and Drycoolers
GOAL: To understand different type of head rejection devices operation temperature and use in winter operation
OBJECTIVES: Student will be able to:
Identify & define an evaporative condenser, an evaporative fluid and a drycooler
Discuss temperature drop across each
Discuss winter operation, types of sump heaters, fan cycle controls
SUBJECT CONTENTS: Trade (terms) language
Taking temperature
Check performances
Venting lines
Safety with electrical around water
METHODS/
TECHNIQUES:
Work book handouts
Overheads
Large troubleshooting charts
RESOURCES: Marley
EDPAC
BAC
Mammoth Inc.
North American Heat Transfer
Heat Craft
EVALUATION: Homework
Quiz
   
DAYS 11 & 12 SUBJECT: Using Troubleshooting Chart to Find Component Problems
GOAL: To be able to diagnose problems where chart leaves off by reason & logic
OBJECTIVES: Student will be able to:
  • Solve refrigerant service calls
  • Check components mechanical & electrical
  • Diagnose multiple problems
SUBJECT CONTENTS: Dealing with customers poor attitudes
Service Industry term & language
Care in taking pressure & temperature reading
Safety on ladders & electric shock
Rules for diagnosing
Problem — to solve
METHODS/
TECHNIQUES:
Refrigeration & A/C Technology W.J.T.
Large troubleshooting chart
Work book
Service calls
System room — role playing
RESOURCES: Refrigeration & A/C Technology W.J.T.
EVALUATION: Quiz
Homework
PBF
Solving Service Problems