iii Preface Essential Electrical Skills for HVACR: Theory and Labs addresses today’s need to produce HVACR technicians that are proficient in electrical fundamentals and troubleshooting modern HVACR systems. This is a combined electrical text and lab manual that provides a practical approach to core electrical theory supported by integrated, hands-on labs. With concise coverage of the material required to find success in the field, each chapter is presented in a logical, linear order where learning is reinforced by the previous chapter and built upon in the next one. This text serves as supplemental electrical material for those currently using Modern Refrigeration and Air Conditioning as part of their HVACR curriculum. Essential Electrical Skills for HVACR provides numerous detailed illustrations and examples to visually depict component operation and support electrical theory. Forty- five hands-on labs are included in the text, following each chapter as opportunities to apply learning into trade-related practices. End-of-chapter review questions also provide a final reinforcement to evaluate student comprehension. This text has a strong emphasis on electrical troubleshooting, which begins with a solid understanding of electrical fundamentals. These fundamentals, such as construct- ing a simple circuit, applying Ohm’s law, application of alternating and direct current, and reading the various types of electrical diagrams are presented concisely in early chapters for students to master. Students will practice using electrical hand tools, preparing wire terminations, and working with various components. They will also be instructed on how to assemble and operate a universal lab board that is required for most labs assignments in later chapters. Once these basic proficiencies are established, the text will cover special features, including multimeter operation, troubleshooting microprocessor-based printed circuit boards, and exploring HVACR systems. A technician must know how a multimeter works in order to troubleshoot successfully and provide accurate analysis. Lacking this under- standing can lead to inaccurate diagnoses of system operation. To maximize trouble- shooting skills necessary for modern electrical systems, this text covers in detail how a multimeter works and expectations about what the meter can do. Students will then transition to microprocessor-based printed circuit boards and learn how to troubleshoot them. These are found in most systems today and, thus, the HVACR technician must be prepared to troubleshoot these systems proficiently. These labs will use a real circuit board, an integrated furnace control, for evaluation by the stu- dent. The student will provide the necessary input signals sequentially to produce the desired operation outcome. The lab will also guide the student to analyze failure modes. Students will wrap up the text with practice on troubleshooting HVACR systems that include the use of wiring diagrams.