Air Conditioning Systems Principles, Equipment, and Service

by AHRI; Moravek, Joseph

• ISBN13: 9780135179215
• ISBN10: 0135179211
• Edition: 1st
• Format: Paperback
• Copyright: 2000-09-19
• Publisher: Pearson

Summary

Some of the features include: bull; bull;Detailed coverage of charging procedures with information not often found in manufacturer's manuals. This helps the technician perform this critical operation correctly. bull;Heavily illustrated coverage of electrical theory and how it applied to air conditioning systems. Technicians will be better prepared to troubleshoot electrical problems. bull;Emphasis on preventative maintenance. Technicians learn to head off problems before they occur.

Table of Contents

Safety on The Job	1	(13)
Personal Safety	2	(1)
Protective Clothing and Equipment	2	(2)
Harmful Substances	4	(1)
Safe Work Practices	5	(4)
Safety When Working with Electricity	9	(1)
Refrigeration Safety	10	(4)
Refrigeration Cycle: How The System Cools	14	(20)
Introduction	14	(1)
Compressor	15	(3)
Condenser	18	(6)
Metering Device	24	(4)
Thermostatic Expansion Value	28	(1)
Capillary Tube and Fixed-Orifice Device	28	(3)
Evaporator	31	(3)
Leak-Detection Procedures	34	(16)
Introduction	34	(1)
Leak Detection	34	(11)
Major Sources of Leaks	45	(1)
Leak-Repair Requirements	46	(1)
Gas Identifiers and Monitors	47	(3)
How to Charge Air-Conditioning Systems	50	(25)
Introduction	50	(1)
Equipment and Instrument Requirements	51	(1)
Supplies and Information	51	(1)
Preparing to Check the Charge	51	(2)
Gaining Access to the Sealed System	53	(9)
Pressure Measurements	62	(2)
Entering the Sealed System	64	(3)
Refrigerant Charging	67	(3)
Liquid Charging	70	(1)
Charge Faster and Safer	71	(1)
Charging the System with Oil	72	(3)
Charging Procedures: Pressure-Temperature Method	75	(13)
Why Learn Proper Charging Techniques?	75	(1)
Safety First	76	(1)
Pressure-Temperature Method of Checking a Charge	77	(1)
Assumptions	77	(8)
Charging Examples Using the Pressure-Temperature Method	85	(3)
Charging Procedures: Superheat Methods	88	(14)
Chapter Overview	88	(1)
Definition of Superheat	88	(1)
What You Will Need to Start the Charging Procedure	89	(1)
Suction-Superheat Method of Checking a Charge	90	(3)
Suction Superheat	93	(4)
Discharge-Superheat Method of Checking a Charge	97	(3)
Discharge-Line Temperature	100	(2)
Charging Procedures: Subcooling, Amperage Draw, and Manufacturing Recommendations	102	(12)
Subcooling Charging Method	102	(2)
What Subcooling Tells Us About the System	104	(1)
High-System Subcooling	105	(1)
Low-System Subcooling	105	(1)
Amperage-Draw Method	106	(3)
Manufacturer's Charging Recommendations	109	(5)
Temperature-Difference, Sight-Glass, and Sweatback Methods	114	(9)
Introduction	114	(1)
Temperature-Difference Method	114	(4)
Sight-Glass Method	118	(3)
Sweatback Method	121	(2)
Weigh-In, Frostback, and Approach Charging Methods	123	(17)
Introduction	123	(1)
Weigh-in Charging Method	123	(2)
Digital Scale	125	(2)
Charging Cylinder	127	(2)
Frostback Method	129	(5)
Approach Charging Method	134	(1)
HVAC Charging Checklist	135	(5)
Troubleshooting Air-Conditioning Systems	140	(7)
Introduction	140	(1)
Types of System Troubleshooting	140	(1)
Where to Start?	141	(4)
Quick Checks	145	(1)
Operator Error	145	(1)
Troubleshooting Process	145	(2)
MECHANICAL TROUBLESHOOTING-----PART ONE	147	(13)
Safety	147	(1)
General Information	147	(1)
Problem Analysis	148	(1)
Air-System Problems	148	(2)
Refrigeration-System Problems	150	(1)
Analyzing Problems	151	(9)
MECHANICAL TROUBLESHOOTING-----PART TWO	160	(15)
Overview	160	(1)
Mechanical Refrigeration Troubleshooting	160	(2)
Troubleshooting the Compressor	162	(3)
Analysis of a Dead Compressor	165	(1)
Troubleshooting Evaporators and Condensers	165	(3)
Troubleshooting Metering Devices	168	(7)
MECHANICAL TROUBLESHOOTING-----PART THREE	175	(15)
Introduction	175	(1)
Basic Refrigeration-Side Problems	175	(5)
Advanced Troubleshooting	180	(10)
The Electrical Side of Air Conditioning	190	(24)
Introduction	190	(1)
Complete Electrical Circuit	190	(6)
Using the Ohm's and Watts Pie Charts	196	(6)
Electric Meters	202	(12)
Troubleshooting Electrical Components	214	(44)
Introduction	214	(1)
Technician Tools: Digital versus Analog Multimeters	214	(2)
Control Transformers	216	(1)
Volt-Ampere Rating	217	(1)
Troubleshooting Control Transformers	218	(5)
Troubleshooting Capacitors	223	(8)
Troubleshooting Contactors and General Relays	231	(9)
Troubleshooting Compressors	240	(18)
Understanding Electrial Diagrams	258	(21)
Introduction	258	(1)
Electrical Symbols	259	(1)
Defining Circuit Types	259	(7)
Types of Electrical Diagrams	266	(6)
Drawing an Electrical Diagram	272	(7)
Troubleshooting Electrical Diagrams	279	(19)
Introduction to Using Electrical Diagrams as Troubleshooting Tools	279	(1)
Electrical Troubleshooting	280	(4)
Other Troubleshooting Methods	284	(9)
Troubleshooting a Wiring Diagram	293	(5)
Preventive Maintenance	298	(20)
Preventive Maintenance versus Emergency Service	298	(1)
Scheduling Preventive Maintenance	299	(1)
Maintenance Contracts	299	(1)
Measurement and Analysis	300	(1)
Preventive Maintenance Routines	301	(2)
Ultimate Spring Tune-Up	303	(1)
Preventive Maintenance Report	304	(10)
Preventive Maintenance Options	314	(4)
HVAC/R Industry Certification	318	(21)
Industry Certification	318	(1)
Industry Competency Exam for Students	319	(1)
ICE Practice Questions	319	(2)
Experienced Technician Certification Program	321	(2)
General Practice Questions	323	(6)
Specific Sector Practice Examinations	329	(8)
Appliance Certification	337	(2)
Appendix Useful Formulas, Conversions, and Common Abbreviations	339	(6)
Glossary	345	(10)
Index	355

Excerpts

PREFACE Much of the information in this textbook is based on the Air Conditioning and Refrigeration Institute (ARI) Curriculum Guide. The curriculum guide was developed by leaders of the air-conditioning industry to act as a standard of what entry-level air-conditioning technicians should know when they enter the field. The ARI Curriculum Guide is a compilation of many labor-hours of serious discussion and thought about what to expect of an entry-level technician. This book addresses many of these important points. The title, Air Conditioning Systems: Principles, Equipment, and Serviceprepares the reader for the book''s content. The focus on the book is on air-conditioning systems and the components that make up these systems. The text discusses how the system and system components operate as a cooling unit. Another emphasis of the book is to provide information that will be useful to the service technician and suggest ways to maintain, service, and troubleshoot air-conditioning equipment. There are many practical and useful ideas in the chapters that follow. Our goal is to provide theoretical and practical information to the entry-level technician. The practical information could be used to design laboratory activities. Generally, educators and the air-conditioning industry are advocates of competency-based education. Competency-based education means that students exhibit their learned skills in several different ways. The student should be able to write or draw an explanation of how something in an air-conditioning system operates. For example, the student should be able to draw the basic refrigeration cycle and list all the entering and leaving conditions of each of the four major components. In addition, he or she should be able to exhibit his or her practical knowledge of an air-conditioning system. Practical knowledge is tested by having the student identify the four major components of an active air-conditioning system and measure the pressures and temperatures entering and leaving each of these components. The critical part of competency-based education is being able to exhibit to the instructor that the student can do basic field-related work. Competency needs to be displayed on an ongoing basis throughout a student''s coursework. Most students can do a lab activity correctly one time. The problem with doing it one time is that the behavior is not repeated, so it is quickly forgotten. For example, when describing charging procedures, the text begins with the basic pressure-temperature method of charging. It builds on this charging procedure by adding other methods, such as checking superheat, subcooling, and amperage. Each time a new charging procedure is introduced, students use previously learned charging methods along with the newly learned charging skill. This builds on the charging procedures and reinforces the charging methods previously learned. Students will retain this knowledge when they demonstrate repetitive skilled behavior. In any event, repeating the exercises correctly several times during a course will commit the behavior to memory and it will become second nature. This book was written to supplement and advance skills of the entry-level student. It is not intended to be a textbook for first-semester students unless they are enrolled in other basic coursework. The user of this textbook should have a basic knowledge of the refrigeration cycle, basic skills in electrical troubleshooting, and an understanding of the uses of the multimeter. Students should have already taken an air-conditioning course that included basic laboratory activities. The sooner students place this information into practice, the sooner they will develop habits that are important for a professional career in air conditioning. Chapters include extensive coverage of charging airconditioning systems and refrigerant and electrical troubleshooting procedures. The troubleshooting section includes both component diagnostics and system diagnostics. The book includes important chapters on safety and the refrigeration cycle. Preventive maintenance is a big part of equipment longevity. The chapter on preventive maintenance is extensive and can be used as a guide for servicing. The chapter on industry certification explains the different options available to the entry-level technician and the experienced professional. The student''s success is the most important objective of the writer and reviewers. Information must be placed into practice for it to be useful and retained. This is a useful source of technician knowledge in the classroom and in the air-conditioning field. Enjoy your learning journey. As long as you are in air-conditioning technology, you will always be learning something new. ACKNOWLEDGMENTS I would like to thank all those who were instrumental in facilitating the completing of this book, starting with my wife, Martha, who has always been supportive of my many ventures over the many years of our marriage. Leslie Sandler of ARI encouraged me to write this book and set up the contacts to begin this journey. In the 1970s, my start in air conditioning began with Walter Hunt at the Gulf Coast Community Services, Houston, Texas, energy conservation program. Next, my knowledge and experience expanded while working under the supervision of Barby Barbara at the Texas Energy Extension Services at the University of Houston. My career diversified with employment at the City of Houston, Texas. While working for the City of Houston, I was exposed to commercial energy conservation, HVAC/R maintenance, and air-conditioning inspections. Guy Ellyson, Chief HVAC Inspector for the City of Houston, motivated me to learn more about the air-conditioning trade. Next, Larry Giroux, chief trainer of AES Houston, became a driving force behind my knowledge of the trade. For the past eighteen years I have learned from Larry and bothered him with problems and concerns I have had regarding air-conditioning systems and instructional delivery methods used to train technicians. He is a mentor to me. My current employer, Lee College, has been a supporter of this project by allowing me the opportunity to write and learn during the summer. Allowing me free rein of an air-conditioning training program has taught me much. Lee College encourages writing as a way of growth and professional development. I must thank all my students who keep me challenged. Many of their mistakes have been shared in this book so as not be repeated by new students. I have learned much from my students. They are creative in ways of getting things done while maintaining a professional sense about their work in the classroom and in the laboratory. I would be remiss if I did not thank Prentice Hall editor Ed Francis for his guidance on this long project. I must give a special thanks for the final editing done by Linda Thompson, and the project management skills of Lisa Garboski of bookworks. They really "cleansed" the material and molded it into the professional document that you see. These women know their air conditioning grammar, or at least they have me fooled. I must also thank Larry Jeffus of Eastfield College, a prolific author himself, for sharing his experiences and advice as an author. Finally, I must thank all those organizations, companies, and corporations that contributed and allowed me to use their material in this book. This was one of the most difficult tasks on the road to developing this textbook. Gathering appropriate materials and gaining approval for their use was a monumental effort. The completion of this book would have been impossible without their help.