iv About the Author Ernesto Reina is an instructor at Lincoln Technical Institute, where he has taught courses in HVACR and for electrical-electronics service technician and customized training pro- grams. He also is an alumnus from Lincoln Technical Institute, where he developed a spe- cial interest in troubleshooting electrical systems. He then moved on to receive a diploma in Industrial Electronics from RETS Electronics Institute and pursued an A.A.S in Elec- tronics Engineering Technology from Union County College, New Jersey. Before becoming an instructor, Ernesto worked at General Motors (GM), where he expanded his knowledge in mechanic, electrical, and manufacturing engineering through corporate training and work experience. His responsibilities included HVACR and electric system quality assurance. He had the opportunity to learn about the design and manufacturing process for electromechanical components and computerized con- trol systems. He designed and developed specialized test equipment for root cause analy- sis of failed components. During his career, he also provided electrical training to the in-house repair personnel. Mr. Reina has received the Certified Master HVACR Educator (CMHE) certificate from HVAC Excellence. The CMHE certificate requires passing six subject matter expert exams. He is a Specialist Member (electrical) of the Refrigeration Service Engineers Soci- ety (RSES) and received the Imperial award for scoring the highest test grade in the coun- try. He is a licensed master HVACR contractor in New Jersey.