Electrical Theory for Troubleshooters
iKNOW
This library consists of 12 interactive, on-line lessons. These lessons are excellent for the training of electricians and electronic technicians as well as for the multi-craft training needs of process and manufacturing facilities. The first four lessons in this library cover basic electrical concepts including Ohm’s Law and Kirchhoff’s Law, as well as the use of these laws to determine voltage, current, and resistance in series and parallel circuits.
- 1. Introduction to Electricity
- 2. Basic Electrical Properties
- 3. Series Circuits
- 4. Parallel Circuits
- 5. Alternating Current
- 6. Electromagnetism
- 7. Inductance
- 8. Capacitance
- 9. Three-Phase Circuits
- 10. Wye and Delta Connections
- 11. Introduction to Transformers
- 12. Transformers
Introduction to Electricity
Description: This is the first lesson in the iKNOW™ Electrical Theory for Troubleshooters Library. This lesson uses animation to demonstrate atomic structure, electricity, and how a simple circuit operates. The lesson also explains the characteristics of good conductors and insulators.
Prerequisites: None
Topics:
Atomic Structure
What is Electricity?
Conductors and Insulators
Circuits
Objectives:
- Describe the atomic structure of matter
- Describe the characteristics of good conductors and insulators
- Define electricity
- Describe how a simple circuit operates
Basic Electrical Properties
Description: This is the second lesson in the iKNOW™ Electrical Theory for Troubleshooters Library. This lesson covers Ohm’s Law, as well as the use of Ohm’s Law to calculate an unknown value. The lesson also defines voltage, current, resistance, and power.
Prerequisites: Completion of the lesson, Introduction to Electricity, is recommended.
Topics:
Voltage
Current
Resistance
Ohm’s Law
Power
Objectives:
- Define voltage
- Define current
- Define resistance
- Describe voltage and current relationships
- State Ohm’s Law
- Use Ohm’s Law to calculate an unknown value
- Define power and how to use power values with Ohm’s Law
Series Circuits
Description: This is the third lesson in the iKNOW™ Electrical Theory for Troubleshooters Library. The lesson presents the operation of a series circuit and trains participants in the identification of simple schematic symbols used to represent components in a series circuit. The behavior of current, resistance, and current in a series circuit, and the used of Kirchhoff’s Voltage Law to find total voltage are also covered.
Prerequisites: Basic understanding of electrical circuits and a solid understanding of Ohm’s law is recommended.
Topics:
Series Circuit Operation
Schematic Symbols
Series Resistance
Voltage Drop
Kirchhoff’s Law
Troubleshooting
Objectives:
- Define a series circuit
- Properly identify simple schematic symbols for a battery, switch, lamp, resistor, and conductor
- Describe how current and resistance behave in a series circuit
- Describe how voltage behaves in a series circuit
- Use Kirchhoff’s Voltage Law to find total voltage in a series circuit
Parallel Circuits
Description: This is the fourth lesson in the iKNOW™ Electrical Theory for Troubleshooters Library. This lesson describes the behavior of voltage, current, and resistance in a parallel circuit. The learner is also instructed in the identification of the series and parallel portions of a series-parallel circuit.
Prerequisites: Understanding Ohm’s Law, Kirchhoff’s Law, and series circuits is recommended.
Topics:
Voltage in Parallel Circuits
Current in Parallel Circuits
Resistance in Parallel Circuits
Series – Parallel Circuits
Objectives:
- Describe how voltage and current behave in a parallel circuit
- Describe how resistance behaves in a parallel circuit
- Identify the series portions of a series-parallel circuit
- Identify the parallel portions of a series-parallel circuit
- Simplify a series-parallel circuit to determine how voltage, current and resistance behave
Alternating Current
Description: This is the fifth lesson in the iKNOW™ Electrical Theory for Troubleshooters Library. This lesson teaches the basic AC characteristics of voltage, including how voltage changes over time. The participant is also instructed in using sine waves to interpret the frequency of AC voltage.
Prerequisites: This lesson was designed for participants familiar with Ohm’s Law.
Topics:
Overview
Polarity and Magnitude
Sine Wave
Frequency
Troubleshooting
Objectives:
- State the basic operating AC Characteristics of voltage
- Explain how AC voltage changes over time
- Define sine wave and cycle
- Interpret the frequency of AC voltage using a sine wave
- Explain RMS voltage vs. peak voltage
Electromagnetism
Description: This sixth lesson in the iKNOW™ Electrical Theory for Troubleshooters Library uses animations and demonstrations to explain the principles of magnetism, including flux density and electromagnetic induction. The lesson also shows how to plot a sine wave using a graph.
Prerequisites: This lesson was designed for participants familiar with AC characteristics.
Topics:
Understanding Magnetism
Principles of Magnetism
Flux Density
Electromagnetic Induction
Induced Voltage Sine Wave
Objectives:
- Describe the principles of magnetism
- Describe flux and flux density
- Describe how electromagnetic induction takes place
- Describe how a magnetic field is generated by passing current through a conductor
- Plot a sine wave using a graph
Inductance
Description: This is the seventh lesson in the iKNOW™ Electrical Theory for Troubleshooters Library. This lesson builds on the information presented in the lesson, Electromagnetism. Types of induction, phase, and the effect of induction in AC circuits are covered.
Prerequisites: This lesson was designed for participants familiar with alternating current and electromagnetism.
Topics:
Current Flow
Self-Inductance & Mutual Induction
Coils – Mutual Induction
Transformer Induction
Transformer Taps
Effect of Inductance & Phase Relationships
Objectives:
- Describe how a magnetic field is generated by passing current through a conductor
- Explain self-induction
- Explain counter-electromagnetic field
- Describe how current is induced in a coil-type conductor
- Explain mutual induction
- Explain the principle of transformer function
- Explain the function of a tap in transformer construction
- Describe the effect of inductance in AC circuits
Capacitance
Description: This is the eighth lesson in the iKNOW™ Electrical Theory for Troubleshooters Library. This lesson explains capacitors, their function, and how capacitance affects AC circuits.
Prerequisites: This lesson was designed for participants familiar with alternating current, electro-magnetism, and induction.
Topics:
Capacitor Defined
Charging a Capacitor
Discharging a Capacitor
Effects of Capacitance
Objectives:
- Define capacitance and identify its schematic symbol
- Explain how a capacitor becomes charged
- Explain how a capacitor becomes discharged
- Explain how capacitance affects AC circuits
Three-Phase Circuits
Description: This is the ninth lesson in the iKNOW™ Electrical Theory for Troubleshooters Library. This lesson defines 3-phase AC, describes the components and operating principle of 3-phase generators, and using the formula for frequency, shows how rotor speed and the number of poles is related to frequency.
Prerequisites: The lesson requires a fundamental knowledge of electrical theory and technology.
Topics:
Definition of 3-Phase
3-Phase Generators
3-Phase Sine Wave
Frequency
Objectives:
- Define 3-phase AC
- Differentiate between 3-phase and 1-phase AC
- Describe the components and operating principle of a 3-phase generator
- Use a sine wave to show how 3-phase voltage changes over time
- Explain the relationship between frequency and rotor speed
- State and apply the formula for frequency
- Describe how rotor speed and the number of poles related to frequency
Wye and Delta Connections
Description: The tenth lesson in the iKNOW™ Electrical Theory for Troubleshooters Library, this lesson discusses Wye and Delta configurations and explains the relationship between phase and line voltages in various connections, and demonstrates the application of the formula that shows this relationship.
Prerequisites: The lesson requires a fundamental knowledge of electrical theory and technology. Basic knowledge of 3-phase circuits is recommended.
Topics:
3-Wire Wye Configuration
4-Wire Wye Configuration
Delta Configuration
Real and Apparent Power
Objectives:
- Describe the relationship between phase and line voltages in a 3-wire wye connection
- Describe the relationship between phase and line voltages in a 4-wire wye connection
- Describe the relationship between phase and line currents in a delta connection
- Calculate power in a 3-phase load
- Apply the formula that shows the relationship between phase and line currents in a 3-wire wye connection
- Apply the formula that shows the relationship between phase voltage and single-phase load voltage in a 4-wire wye connection
- Describe the the relationship between phase and line voltages in a delta connection
Introduction to Transformers
Description: The eleventh lesson in the iKNOW™ Electrical Theory for Troubleshooters Library, this lesson presents the basic parts of a transformer and their function. The lesson explains turns ratio and its relationship to a transformer’s input and output voltages. The participant is also cautioned regarding the dangers of improper transformer connections.
Prerequisites: The lesson requires a fundamental knowledge of electrical theory and technology.
Topics:
Transformer Parts
Turns Ratio
Avoiding Improper Connections
Objectives:
- Identify and describe the functions of the basic transformer parts
- Explain the relationship between a transformer’s turns ratio and its input and output voltages
- Describe the danger in reversing or stepping-up the voltage
Transformers
Description: This is the final lesson in the iKNOW™ Electrical Theory for Troubleshooters Library. This lesson builds on the information presented in the lesson, Introduction to Transformers. How to determine primary current and voltage, secondary current and voltage, and load is taught. The function of various transformers is also explained.
Prerequisites: The lesson requires a fundamental knowledge of electrical theory and technology. Completion of the lesson, Introduction to Transformers, is required.
Topics:
Determining Secondary Current
Determining Power
Determining Primary Current
3 Phase Transformers
Multi-tap and Autotransformers
Objectives:
- Given the secondary voltage and load, determine the primary current
- Given the primary voltage and load, determine the secondary current
- Given the turns ratio and voltage and current from either the primary or secondary, determine the power
- Given power and primary voltage, determine primary current
- Given primary voltage, determine secondary voltage in a 3-phase transformer
- Describe the configuration of a 3-phase transformer
- State some applications and maintenance precautions for a 3-phase transformer
- Explain the functions and uses of multi-tap transformer and autotransformers