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Electricity and Controls for HVAC/R Technicians

**Icehouse**:

As requested I am starting this thread to help new as well as seasoned "Technicians"

**Icehouse**:

A.O. Smith's Motor book

**Icehouse**:

Electricity Unit 1: Introduction to Electricity

Lesson 1 - Fundamental Concepts of Electricity

Objectives:

* Describe the basic structure of an atom.

* Describe the movement of electrons.

* Define an electric current.

* Explain the difference between conductors and insulators.

* Identify at least five materials that are good conductors, and at least five materials that are good insulators.

* Explain what “charged bodies” are.

* Define static electricity.

* State Coulomb’s Law.

* Explain “electric fields.”

* Define electromotive force (EMF). Lesson 2 - Fundamental Concepts of Magnetism Objectives:

* State the basic laws of magnetism.

* Understand magnetic circuits.

* Describe an electromagnet.

* Understand the difference between “natural” and “artificial” magnets.

* Explain magnetic fields.

* State the two basic theories of magnetism.

* Explain how the earth’s magnetic field works.

* Define the following terms: magnetic shielding, lines of force, magnetic flux, self inductance, mutual induction, and counter electromotive force.

* State Lenz’s Law. Lesson 3 - Voltage = EMF = Potential Difference Objectives:

* List and describe each of the basic methods of producing electricity.

* Explain the difference between “cells” and “batteries.”

* Explain the difference between primary cells and secondary cells.

* List the three fundamental requirements for producing a voltage by means of magnetism.

* Define the terms current, ampere, and coulomb.

* Solve problems involving current, charge, and time. Lesson 4 - Fundamental Concepts of Direct Current Objectives:

* Define direct current.

* Define the terms voltage, amperage, resistance, and wattage.

* State the three basic equations of Ohm’s Law.

* Describe and recognize a simple series circuit.

* State and explain Kirchhoff’s Law pertaining to voltages in series circuit.

* Describe and recognize a simple parallel circuit.

* State the equations used to determine power consumption in a simple resistive circuit, and apply the equations to solve circuit problems. Lesson 5 - Fundamental Concepts of Alternating Current Objectives:

* Explain alternating current.

* Define peak-to-peak, RMS, and average voltage values.

* Explain sine waves.

* Describe the phase relationships between currents and voltages in capacitive and inductive reactive circuits.

* Determine the capacitive reactance of a circuit, given the value of the capacitor, frequency, and voltage.

* Determine the inductive reactance of a circuit, given the value of the inductor, frequency, and voltage.

* Determine the impedance of a circuit, given the values of the inductive and capacitive reactance, and the resistance.

* Calculate the ”apparent” power and the “true” or “actual” power of a circuit.

* Determine the power factor of a circuit, given the true power, the voltage, and the amount of current draw. Lesson 6 - Series and Parallel Circuits Objectives:

* Describe what causes resistance in a wire.

* Define an ohm.

* State the three basic equations derived from Ohm’s Law.

* Explain how Ohm’s Law can be applied for a series circuit.

* Explain how Ohm’s Law can be applied for a parallel circuit.

* Define electric power.

* State the three basic equations for calculating power.

* Define a kilowatt-hour. Lesson 7 - Electrical Symbols and Schematic Diagrams Objectives:

* Identify the electrical symbols used in schematic diagrams, and the components that they represent.

* Read and use basic wiring diagrams, including “label”-type diagrams and schematic of “ladder”-type diagrams.

* Identify the “line” side and the “load” side of a schematic diagram, and explain the difference.

* Construct simple schematic or “ladder”-type diagrams. Lesson 8 - Electrical Safety Objectives:

* Describe the different levels of electric shock, and explain their effects on the human body.

* Identify the kinds of accidents caused by electric shock.

* State the precautions against shock.

* Differentiate between hot, neutral, and ground wires.

* Explain the proper grounding of electric power tools.

* Describe what a GFCI is and how it operates.

* Explain how to lock out a system.

* List the three basic forms of fires.

**Icehouse**:

Electricity Unit 2 - Electrical Components

Lesson 1 - Resistors and Resistance

Objectives:

* Describe the differences among various types of resistors.

* Describe the basic structure of resistors.

* Explain how electrons move through a resistor.

* Explain how resistive materials function.

* Find the resistance value of resistors.

* Calculate the wattage requirement of a resistor.

* Calculate the value of resistors in series.

* Calculate the value of resistors in parallel.

* Explain the difference between single-phase ac resistance the three-phase ac resistance.

* Calculate the total current in a resistance network of a three-phase circuit. Lesson 2 - Capacitors and Capacitance Objectives:

* Explain the basic structure of capacitors.

* Describe the movement of the electrons in a capacitor.

* Define dielectric.

* Calculate the value of capacitors in series.

* Calculate the value of capacitors in parallel.

* State the basic rules of capacitance.

* Test capacitors for shorts, opens, and values.

* Calculate the capacitive reactance of a capacitor. Lesson 3 - Inductors and Inductance Objectives:

* Define inductance and describe how an inductor works.

* Explain the difference between self-inductance and mutual induction.

* Define electromotive force and counter electromotive force.

* State Lenz’s Law.

* Define inductive reactance.

* Calculate inductive reactance.

* Explain how to solve for inductance when inductors are connected in series.

* Explain how to solve for inductance when inductors are connected in parallel. Lesson 4 - Transformers Objectives:

* List the main components of a transformer.

* Describe the basic operation of a transformer.

* Explain the relationship between turns and voltage.

* Calculate primary and secondary voltages.

* Describe how and when transformers are connected in series and in parallel.

* Explain the common applications of control transformers and autotransformers. Lesson 5 - Relays and Contactors Objectives:

* Describe the basic construction of a relay.

* Explain how a contactor works.

* Describe the operation of a potential relay.

* Describe the operation of an impedance relay.

* Calculate the impedance of relay coil.

* Explain the term ”delay on make.”

* Explain the term ”delay on break.”

* Identify the different types of time-delay relays. Lesson 6 - Motors Objectives:

* Calculate the synchronous speed of a motor.

* Explain what slip is, and demonstrate how to calculate it.

* Identify the start and run windings in a motor.

* Describe the operation of a shaded-pole motor.

* Describe the operation of a permanent split-capacitor motor.

* Describe the operation of a three-phase motor.

* Explain how a stepper motor works.

* Define service factor. Lesson 7 - Circuit Protection Devices Objectives:

* Discuss the conditions under which circuit protection is needed.

* Describe the different types of fuses.

* List the main components and explain the basic function of circuit a breaker.

* Describe the operation of overload protectors used on compressors and motors.

* Explain the difference between “inherent” overload protection and “external” overload protection.

* Describe the various types of electronic motor protectors. Lesson 8 - Conductors Objectives:

* Explain how conductor sizes are measured.

* Calculate the cross-sectional area of a conductor in square mills and circular mills.

* Define the term ampacity.

* Explain the difference between solid wire and stranded wire.

* Explain the purpose of insulation and describe different types of insulation.

* Discuss the difference between low-voltage control wiring and high-voltage control wiring. Lesson 9 - Power Supplies Objectives:

* Describe basic power distribution systems for residential and light commercial applications.

* Explain the difference between three-phase power and single-phase power.

* Explain what a “stinger” leg is, and why it is used.

* Describe how single-phase power can be derived from a three-phase power supply.

* Explain the difference between wye and delta transformers. Lesson 10 - Basic Controls Objectives:

* Explain the need for automatic control systems.

* Identify the four major classifications of automatic control systems.

* Explain the difference between two-position (on/off) controls and proportional controls.

* Describe the operation of a three-wire oil failure control.

* Describe the operation of four-wire oil failure control.

* Describe the operation of electric defrost controls.

* Describe the operation of pump-down controls.

* Describe the operation of Carrier’s Time Guard and Cycle-Loc controls.

* Describe the operation of a “winter start relay.” Lesson 11 - Miscellaneous Components Objective:

* Describe the operation and application of the following miscellaneous components: Ignition devices:

* glow coils

* hot-surface ignitors

* spark ignition systems

* Safety devices:

* heat-sensitive fuse links

* lame roll-out switches

* cadmium sulfide cells

* mercury flame sensors

* thermocouples

* powerpiles

* Control devices:

* multistage sequencers

* head pressure controllers

* pressure sensors

* dc motors

* thermistors

* resistance temperature detectors

**Icehouse**:

Electricity Unit 3 - Basic Electronics

Lesson 1 - Back to Basics

Objectives:

* Define resistance and explain how resistors work.

* Define capacitance and explain how capacitors work.

* Define inductance and explain how inductors work.

* Describe how the basic “building blocks” of matter--elements, compounds, molecules, atoms, and so on--are related to each other, and how atomic structure is related to the study of electricity.

* Define the coulomb, volt, ampere, ohm, and watt, and use these units of measurement properly.

* State Ohm’s Law.

* Use the equations commonly derived from Ohm’s Law to calculate voltage, current, resistance, and power in electric circuits.

* Explain the difference between series circuits and parallel circuits. Lesson 2 - Solid-State Fundamentals Objectives:

* Explain how semiconductors differ from conductors and insulators.

* Explain how a semiconductor is affected by doping.

* Define the term diode and give a brief description of its construction and operation.

* Explain how external voltages applied to semiconductor devices create a forward bias or a reverse bias.

* Define the term transistor and give a brief description of its construction and operation.

* Describe the bias polarity requirements for both NPN and PNP transistors. Lesson 3 - Diodes and Power Supplies Objectives:

* Define rectification.

* Explain how a diode can be used as a half-wave rectifier.

* Explain how diodes can be used as full-wave rectifiers.

* Describe the basic operation of a bridge rectifier.

* Describe the basic construction, operation, and applications of a variety of special-purpose diodes, including LEDs, Zener diodes, diacs, varactors, tunnel diodes, and photodiodes. Lesson 4 - Power Supply Regulation and Filtration Objectives:

* Explain the need for regulation and filtration in power supplies.

* Describe basic resistive/capacitive regulation and filtration.

* Describe basic inductive/capacitive regulation and filtration.

* Explain how a Zener diode can be used in a power supply circuit.

* Describe the operation of a multistage filter network.

* Explain the purpose of fixed and adjustable voltage regulators.

* Discuss the need for heat sinks on regulators. Lesson 5 - Transistors Objectives:

* Define the term transistor and give a brief description of its basic construction and operation.

* Explain the difference between NPN transistors and PNP transistors.

* Identify different types of transistors by their schematic symbols. Explain the concepts of current gain, voltage gain, and power gain.

* Explain how a transistor can be used to amplify a signal.

* Explain how a transistor can be used as a switch.

* Describe the basic operation of a unijunction transistor (UJT), a field-effect transistor (FET), and a phototransistor. Lesson 6 - Silicon-Controlled Rectifiers Objectives:

* Describe the basic construction and operation of a silicon-controlled rectifier (SCR).

* Explain how the SCR is “gated” on and off.

* Explain what effect the removal of the gate signal has on an SCR.

* Describe the two basic types of gate “turn-on” circuits.

* Explain the difference between single-phase and three-phase alternating current SCR control.

* Describe the basic construction and operation of light-activated SCRs and optocoupled SCRs. Lesson 7 - Triacs, Diacs, and Solid-State Relays Objectives:

* Explain how the development of the triac has made HVACR controls more versatile.

* Explain the difference between a triac and an SCR.

* Describe how a triac is “gated” on and off.

* Explain how and why triacs can be used on resistive and inductive loads.

* Describe the operation of three-phase triacs.

* Describe the basic construction and power limitations of a triac.

* Explain how a solid-state relay functions. Lesson 8 - Peltier Diodes Objectives:

* Explain what the Seebeck effect is.

* Explain what the Peltier effect is.

* Describe the basic construction and operation of a Peltier diode.

* Identify common applications of electronic refrigeration. Lesson 9 - Protective Devices Objectives:

* Explain the need for protection in solid-state electronic equipment.

* Define a transient, and explain how it can damage electronic equipment.

* Describe the operation of a pi filter.

* Explain how a metal-oxide varistor (MOV) functions.

* Describe how and where spark arrestors and snubbers are used.

* Explain how crowbar circuits protect against excessive voltage. Lesson 10 - Number Systems Objectives:

* Explain the difference between analog and digital.

* Explain why the standard decimal number system cannot be used in computers.

* Define the basic terms that are common to all number systems--unit, symbol, base, exponent, and power.

* Explain how positional notation works when applied to the decimal and binary number systems.

* Convert binary numbers to their decimal equivalents.

* Convert decimal numbers to their binary equivalents.

* Add binary numbers.

* Describe octal and hexadecimal number systems. Lesson 11 - Logic Circuits Objectives:

* Identify general logic conditions, logic states, logic levels, and positive and negative logic as these terms and characteristics apply to the inputs and outputs of fundamental logic circuits.

* Identify basic AND, OR, NOT, NAND, NOR, and exclusive OR gates, and recognize the Boolean expressions for each.

* Construct and interpret truth tables.

* Explain the function of a simple flip-flop circuit. Lesson 12 - Digital Integrated Circuits Objectives:

* Interpret a pinout diagram.

* Explain what the abbreviations TTL, CMOS, DIP, SSI, LSI, MSI, and VLSI mean.

* Describe the six basic configurations of TTL integrated circuits, and give examples of typical applications. Lesson 13 - Analog Integrated Circuits Objectives:

* Explain how analog ICs differ from digital ICs.

* Describe the basic operation of the op amp.

* Identify the three basic functional applications of the op amp.

* Define and calculate gain.

* Explain how and why negative feedback is used in amplifiers.

* Explain how op amps are used in comparator circuits.

* Describe the basic operating characteristics of the 555 timer, the 3909 LED flasher, and the LM383 power amplifier. Lesson 14 - Microprocessors and Computers Objectives:

* Discuss the history and background of computers, and explain how they evolved from mechanical calculating machines.

* Describe the function of a microprocessor.

* Explain the difference between fixed and programmable digital devices.

* Define hardware, software, and firmware.

* Identify the basic components of a computer.

* Explain the difference between parallel and serial transmission of data.

* Use the basic terminology associated with computers.

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