SS103 Electrical Fundamentals v2 - LennoxPROs.com

1 HVAC Essentials Series Electrical Fundamentals Course SS103 Version 2011 HVAC Learning Solutions Page 1 of 73 Course SS103 Electrical Fundamentals HVAC Essentials Series Electrical Fundamentals Course SS103 Version 2013 HVAC Learning Solutions Page 2 of 73 Table of Contents 1. Introduction to Electricity .. 4 Atomic Theory of Matter and Electricity .. 4 How Electricity Is Produced .. 5 Conductors and Insulators of Electricity .. 6 electric Potential (Voltage) .. 7 Current Flow (Amperage) .. 7 Resistance (Opposition to Current Flow).

2 8 Wattage ( electric Power) .. 8 Ohm's Law .. 8 Watt s Law .. 11 Review .. 13 Review Questions .. 15 2. Electrical Circuits .. 19 Electrical circuit Basics .. 19 Source Voltage .. 20 Series Circuits .. 21 Parallel Circuits .. 25 Series-Parallel or Combination Circuits .. 29 Wiring Diagrams .. 29 Review .. 31 Review Questions .. 33 3. Switches .. 37 Single Pole, Single Throw ( ) Switch .. 37 Double Pole, Single Throw ( ) Switch .. 38 Single Pole, Double Throw ( ) Switch .. 38 Double Pole, Double Throw ( ) Switch .. 38 "Need to Know Information" Concerning Switches.

3 39 Other Types of Switches .. 39 Thermostats .. 40 Pressure Switches .. 41 Flow 42 Fuses and Overloads .. 42 HVAC Essentials Series Electrical Fundamentals Course SS103 Version 2013 HVAC Learning Solutions Page 3 of 73 Other Symbols .. 43 4. Loads and 45 Solenoids .. 45 Heaters .. 45 Low Voltage Signal Lights .. 46 Magnetic Controllers .. 46 Transformers .. 50 24-Volt Wall Thermostats for Heating and Cooling Systems .. 52 24-Volt Circuits and Wiring Diagrams .. 53 Motors .. 55 5. Meters, Diagrams, and Troubleshooting.

4 58 Volt Ohm Meters .. 58 Amp Meters .. 59 Ohm Meters: "A Closer Look!" .. 60 Basic Troubleshooting Using a Volt Meter .. 63 Review .. 65 Review Questions .. 66 Appendix: Answers to Review Questions .. 72 Section 1 .. 72 Section 2 .. 72 Section 5 .. 72 HVAC Essentials Series Electrical Fundamentals Course SS103 Version 2013 HVAC Learning Solutions Page 4 of 73 1. Introduction to Electricity The importance of electricity in our modern society is often taken for granted. Without electricity, the heating, cooling, and refrigeration industries would never have advanced beyond ice, saw dust, and the wooden locker.

5 This industry relies on electricity to power and control the components that maintain comfort in our homes and offices. It is for this reason that service technicians need to understand the principles of electricity and be able to troubleshoot these circuits. To begin the study, we ll start with atomic structure. Atomic Theory of Matter and Electricity All matter in the universe is composed of elements. To date, over 100 elements have been found in our universe. To break down the elements, we must look at the atom, which is the smallest particle of an element that can exist alone or in combination with others.

6 The center of an atom is the core or nucleus. The nucleus is composed of protons, which are positively charged particles, and neutrons, which are neither positively nor negatively charged. Atoms of the same element always have the same number of protons (called the atomic number), but the number of neutrons can vary with different atoms of the element. Atoms than contain a different number of protons and neutrons are called isotopes of the element. The other part of the atom is composed of electrons, negatively charged, which orbit the nucleus, very much like our moon orbits the earth.

7 Usually atoms have an equal number of protons and electrons. When this is true, the atom is considered electrically neutral. Under certain conditions, however, either gaining or losing an electron can unbalance an atom. When this occurs an atom can become either negatively or positively charged. HVAC Essentials Series Electrical Fundamentals Course SS103 Version 2013 HVAC Learning Solutions Page 5 of 73 Metal's atomic structure has electrons that can easily be "knocked out of their orbits" around the nucleus. These free electrons and the materials (metals) are called conductors.

8 When an atom loses its electrons, it becomes unbalanced and contains a positive charge. When this occurs the atom can easily attract and acquire additional electrons; this makes the atom negatively charged. When this alternating state of positively then negatively charged particles exists, electrons can flow between the two opposing atoms. This flow of electrons is Electrical energy or electricity. How Electricity Is Produced The movement of electrons or, as we refer to it, a "flow of electrons" is accomplished in several ways. The means most commonly related to HVAC will be discussed here.

9 Chemical A battery produces a flow of electrons by a chemical reaction between two electrodes within the battery. Electrodes by definition are "solid conductors through which an electric current can pass." One electrode in a battery "gives up" the electrons whereas the other electrode "collects" the electrons. The electrodes are constructed of dissimilar metals. When encased within an electrolyte, such as an acid or paste, electricity is produced by the chemical reactions of the electrolyte and conductors. Batteries produce Direct Current (DC), which is electron flow in one direction only.

10 Magnetic Induction or Electricity by Magnetism Magnetic Induction is the most widely used form of electricity generation. This is accomplished by rotating magnets within a coil of wire, whereby the lines of force within the coil cause an alternating current (AC) to flow within the wire. These magnets break the lines of force within the coils of wire and induce alternating current (AC) to be produced. This method of Electrical generation is what powers our homes, our offices, and the heating and air conditioning equipment that maintains our comfort. HVAC Essentials Series Electrical Fundamentals Course SS103 Version 2013 HVAC Learning Solutions Page 6 of 73 Heat If two dissimilar metals are joined together at one end and their junction is heated, a small amount of voltage will be produced.