Author Topic: Electricity and Controls for HVAC/R Technicians  (Read 13321 times)

Offline Icehouse

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    • hvacbob
Electricity and Controls for HVAC/R Technicians
« on: December 19, 2011, 10:04:20 AM »
As requested I am starting this thread to help new as well as seasoned "Technicians"
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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    • hvacbob
Re: Electricity and Controls for HVAC/R Technicians
« Reply #1 on: December 19, 2011, 10:11:39 AM »
A.O. Smith's Motor book
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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    • hvacbob
Re: Electricity and Controls for HVAC/R Technicians
« Reply #2 on: December 19, 2011, 12:55:27 PM »
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.
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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Re: Electricity and Controls for HVAC/R Technicians
« Reply #3 on: December 19, 2011, 12:57:31 PM »
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
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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    • hvacbob
Re: Electricity and Controls for HVAC/R Technicians
« Reply #4 on: December 19, 2011, 12:59:26 PM »
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.
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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    • hvacbob
Re: Electricity and Controls for HVAC/R Technicians
« Reply #5 on: December 19, 2011, 01:02:40 PM »
Electricity Unit 4 - Troubleshooting Components
 

 Lesson 1 - Test Equipment (Part 1)
 Objectives:
 
  • Describe the basic operation of the d’Arsonval meter movement.
  • Explain the difference between analog and digital measuring instruments.
  • Distinguish between voltmeters, ammeters, ohmmeters, and multimeters, and describe the operational principles of each.
  • Explain how the sensitivity of a voltmeter is calculated.
  • Describe how various electrical meters are used to measure resistance, voltage, and current, and to check for continuity.
  • Demonstrate how clamp-on ammeters are used.
  • Describe the basic operation of a Wheatstone bridge, and explain how it can be configured to act as a resistance bridge or a capacitance bridge.
Lesson 2 - Test Equipment (Part 2) Objectives:
 
  • Explain the operation of a wattmeter.
  • Demonstrate how to read a watt-hour meter.
  • Describe how to determine the power factor of a circuit by using a power factor meter.
  • Describe how a varmeter can be used in correcting power factor problems.
  • Explain the purposes and use of various instrument transformers.
  • Explain the operation of megohmmeter.
  • Explain the purpose and use of various recording instruments.
  • Describe how a compressor analyzer can be used in troubleshooting.
Lesson 3 - Resistors Objectives:
 
  • Observe the proper safety precautions when taking ohmmeter readings.
  • Select the best range for a particular resistance measurement.
  • ”zero adjust” an analog ohmmeter.
  • Determine the resistance values of various types of resistors.
  • Use an ohmmeter to test resistors, potentiometers, rheostats, bleeder resistors, thermistors, PTC start-assist devices, and diodes.
Lesson 4 - Capacitors Objectives:
 
  • Observe the proper safety precautions when taking capacitance readings.
  • Explain the differences between start and run capacitors.
  • Discharge a capacitor safely.
  • Describe the four main problems or conditions that identify a faulty capacitor.
  • Describe the operation of various types of instruments used for testing capacitors.
Lesson 5 - Relays, Contactors, and Starters Objectives:
 
  • List common causes of relay failure.
  • Describe the physical indications that identify defective relays and contactors.
  • Explain how to test pilot-duty relays and line-duty relays.
  • Explain how to test contactors and starters.
  • Explain how to test potential relays and current relays.
  • Explain how to test time-delay relays.
Lesson 6 - Transformers Objectives:
 
  • Describe the conditions that cause transformers to fail.
  • Describe the physical indications that identify defective transformers.
  • Explain the differences between residential and commercial transformers.
  • Determine the current-carrying capacity of a control transformer.
  • Explain how to test different types of transformers.
  • Define open circuit voltage (OCV).
  • Test continuity between the primary and secondary windings of a transformer.
Lesson 7 - Thermostats Objectives:
 
  • Describe the basic construction operation of a bimetal mechanical thermostat.
  • Explain the concept of anticipation.
  • Describe some of the physical indications that identify defective thermostats.
  • Test a mechanical thermostat with a voltmeter and/or ohmmeter.
  • Set an adjustable anticipator.
  • Calibrate a mechanical thermostat.
  • Explain the differences between residential and commercial thermostats.
  • Identify common problems that affect electronic thermostats, and explain basic troubleshooting techniques.
Lesson 8 - Motors Objectives:
 
  • List the basic types of motors used in the HVACR industry.
  • Describe some of the visual indications that identify defective motors.
  • Explain the difference between fractional-horsepower motors and integral-horsepower motors.
  • Determine the speed and rotation of a motor.
  • Use appropriate test instruments to troubleshoot various types of motors and their associated starting circuits.
  • Describe some of the causes of overheating in electric motors.
  • Explain what causes single phasing in a three-phase motor.
  • Calculate voltage and current imbalances in three-phase motors.
  • Describe basic motor replacement procedures.
  • Read a motor nameplate.
  • Use NEMA data to determine motor frame sizes and dimensions.
Lesson 9 - Hermetic Compressors Objectives:
 
  • Explain the differences among open, semi-hermetic, and hermetic compressors.
  • Describe the various starting methods used for single-phase hermetic compressors.
  • Explain the function and operation of overload protection devices use in hermetic compressors.
  • Check a single-phase hermetic compressor for proper resistance, voltage, and current readings.
  • Identify the terminals of a single-phase hermetic compressor, even if they are unmarked.
  • Check a three-phase hermetic compressor for proper resistance, voltage, and current readings.
  • Calculate voltage and current imbalances in three-phase hermetic compressors.
Lesson 10 - Semi-Hermetic Compressors Objectives:
 
  • Explain the differences between hermetic and semi-hermetic compressors.
  • Describe the various starting methods used for single-phase semi-hermetic compressors.
  • Check a single-phase semi-hermetic compressor for proper resistance, voltage, and current readings.
  • Identify the terminals of a single-phase semi-hermetic compressor, even if they are unmarked.
  • Check a three-phase semi-hermetic compressor for proper resistance, voltage, and current readings.
  • Calculate voltage and current imbalances in three-phase semi-hermetic compressors.
  • Explain what causes single phasing in three-phase semi-hermetic compressors.
  • Explain the function and operation of overload protection devices use in semi-hermetic compressors.
Lesson 11 - Electronic Components Objectives:
 
  • Explain how to test diodes, both with an analog meter and a digital meter.
  • Explain how to test NPN and PNP transistors.
  • Explain how to test silicon-controlled rectifiers (SCRs).
  • Explain how to test triacs.
  • Describe the effects that electrostatic discharge (ESD) can have on electronic components.
  • List the precautions that you should take to prevent ESD damage when servicing electronic components.
  • Demonstrate logical troubleshooting procedures when diagnosing printed circuit (PC) boards.
Lesson 12 - Wiring Systems Objectives:
 
  • Describe the different types of wiring systems used in the HVACR industry.
  • Test single-phase residential power circuits for voltage drop, voltage imbalance, and current imbalance.
  • Test three-phase commercial power circuits for voltage drop, voltage imbalance, and current imbalance.
  • Define ampacity, and explain how wire sizes are selected for given applications.
  • Troubleshoot low-voltage control circuits.
  • Troubleshoot high-voltage ac control circuits.
  • Troubleshoot direct digital control (DDC) circuits.
  • Describe some of the basic problems encountered in all wiring systems
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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    • hvacbob
Re: Electricity and Controls for HVAC/R Technicians
« Reply #6 on: December 19, 2011, 01:04:52 PM »
Electricity Unit 5 - Troubleshooting Residential Equipment
 

 Lesson 1 - Getting Started
 Objectives:
 
  • Use checklists and log sheets to record information about the equipment you service, and about the service procedures you perform.
  • Identify common warning symbols used by manufactures today, and explain basic electrical safety precautions.
  • Isolate a problem by performing simple electrical troubleshooting tasks in a logical order.
  • Locate a faulty component by using the “hopscotch” method of troubleshooting.
Lesson 2 - Reading Schematics Objectives:
 
  • Read and interpret electrical schematic diagrams correctly as an aid in troubleshooting.
  • Recognize and explain some of the differences between the schematics of one manufacturer and another, including wiring and terminal designations, symbol usage, component placement, and so on.
  • Describe the sequence of operation for the equipment of several different manufacturers by tracing their respective wiring diagrams.
  • Explain how high-voltage and low-voltage power supply information is provided on the schematics of residential and light commercial equipment.
Lesson 3 - Split Systems (Part 1) Objectives:
 
  • Describe appropriate electrical troubleshooting procedures for residential split systems.
  • Develop a logical approach to isolating the cause of a service problem.
  • Read and follow a troubleshooting flow chart.
Lesson 4 - Split Systems (Part 2) Objectives:
 
  • Explain some of the problems encountered with high-voltage gas heating/air conditioning systems.
  • Describe appropriate electrical troubleshooting procedures for these types of residential split systems.
  • Read and interpret the self-diagnostic fault codes used in some high-efficiency furnaces.
  • Locate the probable causes of a service problem (e.g., the electronic thermostat, the printed circuit board, wiring difficulties, etc.).
Lesson 5 - Gas Furnaces (Part 1) Objectives:
 
  • Explain some of the problems encountered with several types of ignition systems and safety controls that are used with gas furnaces.
  • Describe appropriate electrical troubleshooting procedures for these types of heating systems.
  • Read and interpret the schematic diagrams and troubleshooting flow charts provided by the manufacturers of such equipment.
  • Locate the probable cause of a service problem (e.g., the thermostat, the printed circuit board, the wiring, etc.).
Lesson 6 - Gas Furnaces (Part 2) Objectives:
 
  • Explain some of the problems encountered with hot surface ignition (HSI) systems.
  • Describe appropriate electrical troubleshooting procedures for heating systems that use microprocessors, printed circuit boards, and self-diagnostic LEDs.
  • Read and interpret the schematic diagrams and troubleshooting flow charts provided by the manufacturers of such equipment.
Lesson 7 - Oil Furnaces Objectives:
 
  • Explain some of the problems encountered with various types of ignition systems and safety controls that are used with oil-fired furnaces.
  • Describe appropriate electrical troubleshooting procedures for these types of heating systems.
  • Locate the probable cause of a service problem.
  • Evaluate the performance of a cad cell.
  • Use a test lamp to find a shout circuit.
Lesson 8 - Electric Furnaces Objectives:
 
  • Explain some common problems encountered with multistage electric furnaces.
  • Describe appropriate electrical troubleshooting procedures for these types of heating systems.
  • Calculate the actual air flow (in cfm) of an electric furnace.
  • Calculate the temperature rise across a set of electric heaters.
  • Calculate the current draw of an electric heater.
  • Describe the procedure for identifying an open heater.
  • Explain what is meant by “black heat.”
  • Locate the probable cause of a service problem.
Lesson 9 - Air-to-Air Heat Pumps Objectives:
 
  • Explain some common problems encountered with air-to-air heat pump systems.
  • Describe appropriate electrical troubleshooting procedures for these types of heat pumps.
  • Locate the probable causes of typical service problems, including those involving defrost controls and supplemental electric heating sections.
  • Explain the basic operation of a reversing valve, and describe how to diagnose a bad valve.
  • Determine whether the compressor is operating in both the heating mode and the cooling mode.
  • Check the operation of outdoor thermostats.
Lesson 10 - Water-Source Heat Pumps Objectives:
 
  • Explain some common problems encountered with water-source heat pump systems.
  • Describe appropriate electrical troubleshooting procedures for these types of heat pumps.
  • Locate the probable causes of typical service problems, including those involving water flow controls, changeover controls, and lockout controls.
  • Explain the basic operation of a reversing valve, and describe how to diagnose a bad valve.
  • Determine whether the compressor is operating in both the heating mode and the cooling mode.
Lesson 11 - Electronic Air Cleaners Objectives:
 
  • Describe the basic operation of an electronic air cleaner (EAC) and its high-voltage power supply.
  • Explain the purpose of “doubler” rectifier circuits.
  • Discuss some common problems encountered with electronic air cleaners, and describe appropriate electrical troubleshooting procedures for this type of equipment.
  • Locate the probable causes of typical service problems, including those involving safety controls, ozone odors, “white dust,” noisy operation, and television interference.
Lesson 12 - Humidifiers Objectives:
 
  • Describe the basic operation of an evaporative humidifier, and of a steam humidifier.
  • Discuss some common problems encountered with humidifiers, and describe appropriate electrical troubleshooting procedures for this type of equipment.
  • Locate the probable causes of typical service problems, including those involving humidistats, solenoid valves, float switches, and safety controls.
  • Diagnose “too much humidity” and “not enough humidity” complaints.
Lesson 13 - Electrical Troubleshooting Reference Guide This Lesson is intended to serve as a general reference guide for the electrical troubleshooter.  It contains a broad range of technical information, including various tables, charts, symbols, and mathematical equations, as well as service tips and reminders designed to help technicians increase their productivity on the job
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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    • hvacbob
Re: Electricity and Controls for HVAC/R Technicians
« Reply #7 on: December 19, 2011, 01:07:04 PM »
The above is required knowledge to pass the RSES CM (Certified Mechanic) Electricity which is excellent for all tests.
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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    • hvacbob
Re: Electricity and Controls for HVAC/R Technicians
« Reply #8 on: December 19, 2011, 01:10:49 PM »
« Last Edit: December 19, 2011, 01:12:23 PM by Icehouse »
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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    • hvacbob
Re: Electricity and Controls for HVAC/R Technicians
« Reply #9 on: December 19, 2011, 01:30:41 PM »
  PSC Motors - Schematics

Permanent Split Capacitor (PSC) Motors' Schematics

Attached are several Schematics describing the following type Single Phase Induction Motors:

Split-Phase Induction; Permanent Split Capacitor (PSC)

To discuss these items, please refer to the following Thread in the Electrical Theory and Applications Section:

Single Phase Induction Motor

Let me know if you have suggestions, questions or comments.

Scott

*** PLEASE NOTE ***
These Drawings do not include Speed Control; only Start/Stop + Forward / Reverse control.
For Speed Control PSC Schematics, please refer to the Technical Reference Section's "Menu".
Search for the link entitled: "Split-Phase 1Ø Motors: Series 3"


*** Drawings Uploaded 06/05/2008 ***

==============================================================================================

==============================================================================================

*** NOTE ***

Either of the Two (2) "AC-IN" leads may be the System's Grounded ("Neutral") Conductor - for an L-N Circuit (i.e.: 120V, 277V);
or they may both be Ungrounded ("Hot") Conductors - for an L-L Circuit (i.e.: 208V, 240V, 480V).


*** BASIC OPERATION PRINCIPLES ***

This Motor is a Single Phase Squirrel-Cage Induction Motor: Split-Phase, Permanent Split Capacitor.

The Motor's Auxiliary Winding has a low value Capacitor in Series between the Winding and the "Opposite" side of the AC Circuit.

There is no Centrifugal Start Switch in series with the Auxiliary Winding / Capacitor, as would be normal with any other Split-Phase Motors - with the exception of the Cap. Start / Cap. Run Motor, or the Shaded Pole Motor.

The Auxiliary Winding + Capacitor remain connected to the AC Circuit thruout the entire operation of the Motor.

Starting Torque is very low, but Pullout Torque is not so bad!

Speed control of these Motors may be easilly achieved by reducing the input Voltage - either by an external means, or by an intregral Autotransformer wound into the Motor's Windings.

The Speed of the Rotor will be a result of the required True Power (Wattage) needed to drive the load on the shaft, and falling just below a "Slip Frequency" point.

*** STARTING PROCEDURES ***

To get the 1 Phase Motor's Rotor to begin spinning (as opposed to just sitting still), one "Side" of the Main Winding's Magnetic Field must be reduced in intensity. This is achieved by adding the "Auxiliary" (or "Start") winding into the Motor's Circuitry.

At Start, without the Aux. winding, the Main Winding produce an equal Field across its self + the rotor, which results in no Induced VARs (Reactive Power) into the Rotor - so the rotor just sits still.

With the Aux. Winding included to the Circuit, one "Side" of the Main Winding's Field is reduced, which allows for VARs to be Induced into the Rotor - thereby makes the Rotor start to spin.

The Rotor turns toward the "Side/End" of the Main Winding with the larger Field.

Speed increases to the point where the Rotor can develope the needed Torque / Horsepower, by drawing the necessary level of True Power (Wattage) from the Supply (Watage equates to output HP), along with the needed VARs (Reactive Power, or Volt-Amps Reactive).

Both of these Powers are contained in the "Apparent Power" (VA, or Volt-Amps)

Since the Single Phase 2 Wire Circuit has no "Polarity", reversing only the incoming leads will not reverse the Rotor's Direction.

The way the Rotor's Direction is changed is by "Reversing The Relative Polarity" of the Auxiliary Winding, as viewed by the "Relative Polarity" of the Main Winding (the Main Winding's Relative polarity does not get changed).

When this is done, the Magnetic field is reduced on the opposite end of the main Winding, so the Rotor begins to spin towards the "End" of the Main Winding with the larger Magnetic Field.
As a result, the Rotor spins in the opposite direction.

==============================================================================================

==============================================================================================

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------






FIGURE #1-1: BASIC PSC MOTOR CONNECTIONS:
DIRECTION = FORWARD

This Drawing shows the Permanent Split Capacitor Motor (hereafter referred to as "PSC Motor"), with Basic connection scheme for Forward Rotation Direction.


---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------




FIGURE #1-2: BASIC PSC MOTOR CONNECTIONS:
DIRECTION = REVERSE

This Drawing shows the PSC Motor, with Basic connection scheme for Reverse Rotation Direction.


---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------


FIGURE #1-3: BASIC PSC MOTOR CONNECTIONS:
DIRECTION = REVERSE

This Drawing shows what Fig. 1-2 actually looks like to the Rotor.

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------



FIGURE #2-1: DIRECTIONAL PSC MOTOR CONNECTIONS - SWITCH CONTROL:
DIRECTION = FORWARD

This Drawing shows the PSC Motor with SPDT Switches used for Forward / Reverse of the Motor.

Switches are thrown to position for _FORWARD_ Rotation.

"On/Off" Switch controls Motor's input, so if this Switch is Open (Off), the Motor will not run.

----------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------




FIGURE #2-2: DIRECTIONAL PSC MOTOR CONNECTIONS - SWITCH CONTROL:
DIRECTION = REVERSE

This Drawing shows the PSC Motor with SPDT Switches used for Forward / Reverse of the Motor.

Switches are thrown to position for _REVERSE_ Rotation.

"On/Off" Switch controls Motor's input, so if this Switch is Open (Off), the Motor will not run.

----------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------




FIGURE #3-1a: DIRECTIONAL PSC MOTOR CONNECTIONS - CONTACTOR CONTROLLED:
DIRECTION = N/A (MOTOR AT REST)

*** MOTOR CIRCUITRY ***

This Drawing shows the PSC Motor with Contactors used for Forward / Reverse of the Motor.

Control logic State = "REST" (Motor is Off).

See Fig.# 3-1b below, for Control Schematic

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------





FIGURE #3-1b: DIRECTIONAL PSC MOTOR CONNECTIONS - CONTACTOR CONTROLLED:
DIRECTION = N/A (MOTOR AT REST)

*** CONTROL CIRCUITRY ***

This Drawing shows the PSC Motor with Contactors used for Forward / Reverse of the Motor.

Control logic State = "REST" (Motor is Off).

See Fig.# 3-1a above, for Control Schematic

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------



FIGURE #3-2a: DIRECTIONAL PSC MOTOR CONNECTIONS - CONTACTOR CONTROLLED:
DIRECTION = FORWARD

*** MOTOR CIRCUITRY ***

This Drawing shows the PSC Motor with Contactors used for Forward / Reverse of the Motor.

Control logic State = "FORWARD".

See Fig.# 3-2b below, for Control Schematic

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------





FIGURE #3-2b: DIRECTIONAL PSC MOTOR CONNECTIONS - CONTACTOR CONTROLLED:
DIRECTION = FORWARD

*** CONTROL CIRCUITRY ***

This Drawing shows the PSC Motor with Contactors used for Forward / Reverse of the Motor.

Control logic State = "FORWARD".

See Fig.# 3-2a above, for Control Schematic

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------



FIGURE #3-1a: DIRECTIONAL PSC MOTOR CONNECTIONS - CONTACTOR CONTROLLED:
DIRECTION = REVERSE

*** MOTOR CIRCUITRY ***

This Drawing shows the PSC Motor with Contactors used for Forward / Reverse of the Motor.

Control logic State = "REVERSE".

See Fig.# 3-3b below, for Control Schematic

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------





FIGURE #3-3b: DIRECTIONAL PSC MOTOR CONNECTIONS - CONTACTOR CONTROLLED:
DIRECTION = REVERSE

*** CONTROL CIRCUITRY ***

This Drawing shows the PSC Motor with Contactors used for Forward / Reverse of the Motor.

Control logic State = "REVERSE".

See Fig.# 3-3a above, for Control Schematic

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------

 

NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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Re: Electricity and Controls for HVAC/R Technicians
« Reply #10 on: December 19, 2011, 02:04:56 PM »
   [/size]How to check resistance (continuity) in a component-[/color]
  [/size]A Digital Multi-meter (Ohmmeter) is needed for testing components:
An ohmmeter can be used to directly measure an unknown resistance R. This is the simplest way to measure resistance. It is important to realize
that an ohmmeter can not be used when the resistance is connected in a circuit and a current is flowing through it!
 
[/color]Typical Digital Multimeter [/size][/font]
Scale
Measurement Range
in words
ohms (Ω)
2M
two megohm
two million ohms
0-2,000,000
200K
two hundred kilohm
two hundred thousand ohms
0-200,000
20K
twenty kilohm
twenty thousand ohms
0-20,000
2K
two kilohm
two thousand ohms
0-2,000
200
two hundred ohm
0-200
Setting up the meter
To use the multi-meter as an ohmmeter turn the selector dial to point to the ohms range. On some models (usually not on the cheaper ones) the meter will have a single ohms setting and will auto select the best range for you.
To measure resistance you must connect the test leads to the sockets labeled 'COM' and 'Ω'. These may be in different positions on your meter but the labeling should be the same.
Without anything connected between the test leads the display will give an out of range indication (-1 in this case) to show that the resistance is too large to measure. In effect, you are trying to measure the resistance of the air between the two inputs, which is very large.
 
Taking measurements
To check the meter is working touch the leads together and the display should read 0.0 Ω. It may read slightly higher, e.g. 0.3 Ω. This is the resistance of the test leads themselves.Ohm meter and resistance wire height=237 Turn the selector dial to the lowest resistance range that gives a valid reading.
In this case the resistance wire has a resistance of 4.2 Ω.
 
[/size]Accuracy[/color]
The overall accuracy of the reading will depend upon the multi-meter model. The more expensive the meter the better the accuracy will be. For a cheap meter the accuracy is typically in the region of +/- 1% of the displayed value. Check in the manual for the accuracy of your model.
It is important to select the correct measurement range. In the above example if the 2 kΩ range is selected the display will read .004 kΩ and the decimal place will be lost. If the dial is set to 20 kΩ the display may read 0.00 kΩ! Always turn the dial down to the lowest range to get the best accuracy. [/size][/font]
[/size]OHM's Law- [/color]How to calculate resistance and voltage using meter readings:[/size][/font]

 



   
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

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    • hvacbob
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline Icehouse

  • Technician
  • Member Since: Oct 2008
  • Posts: 566
    • hvacbob
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline AJ

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Re: Electricity and Controls for HVAC/R Technicians
« Reply #13 on: December 19, 2011, 07:32:41 PM »
Very nice Icehouse.


I'm going to 'Sticky' this topic to the top so it gets highlighted.


Thanks,   O0
Hope you find our site helpful.

Offline Icehouse

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Re: Electricity and Controls for HVAC/R Technicians
« Reply #14 on: December 19, 2011, 10:25:15 PM »
 O0 O0 You're the best
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

 

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