# Industrial Motors Training

### 409-01 AC Induction Motors

When you complete this lesson, you will be able to describe the design and function of several different types of AC induction motors.

• Identify two main categories of AC induction motors
• List the basic components of an AC induction motor and their functions
• Discuss the operating characteristics of single-phase, AC induction motors
• Compare the design and function of the following pairs of motors:
• A single-phase AC induction motor and a three-phase AC induction motor
• A standard three-phase motor and a wound rotor three-phase motor
• A standard squirrel cage, three-phase induction motor and a three-phase, wound rotor AC induction motor

### 409-02 AC Generators

When you complete this lesson, you will understand how an AC generator produces an AC voltage.

• List the components of a generator
• Describe a rotating field generator
• Identify the purpose of an exciter
• Explain the process of electromagnetic induction
• Describe the sine wave that is formed when a conductor is rotated through a magnetic field
• Identify the difference between a single-phase voltage sine wave and a three-phase voltage sine wave
• Explain the relationship between frequency and speed in an AC generator
• Explain how to increase voltage produced in a conductor

### 409-03 AC Induction Motor Theory

When you complete this lesson, you will be able to describe how an electric AC induction motor uses the principles of magnetism and magnetic fields to convert electrical energy into mechanical energy.

• Describe the makeup of a magnetic field
• State the law of magnetism
• Define the following terms:
• Magnetic flux
• Polarity
• Motor slip
• Synchronous speed
• Describe electromagnetic force
• Discuss the theory behind the operation of single-phase AC motor, rotating stator fields
• Explain the rotation of an AC squirrel cage rotor
• Discuss the three-phase motor’s rotating stator field and its associated waveform

### 409-04 Troubleshooting AC Induction Motors

When you complete this lesson, you will be able to discuss effective troubleshooting procedures for AC induction motors. You will also be able to state various problems related to motor installation, maintenance, and repair.

• Describe five primary steps to take when troubleshooting motors
• Identify the information found on the motor nameplate
• Describe conditions that can cause a motor to trip or fail to start
• Describe the steps for testing motor insulation and the continuity of winding coils

### 409-05 AC Induction Motor Maintenance

When you complete this lesson, you will be able to describe general electric motor maintenance and inspection activities.

• List the common causes of motor failure
• Identify some items to check when visually inspecting an electric motor
• List conditions to watch for when maintaining electric motors
• Discuss the value of checking and monitoring motor operating temperatures
• Describe the difference between sleeve bearings and rolling element bearings
• Describe how lubrication differs between sealed bearings and open face bearings
• List some common causes of vibration
• Discuss the value of monitoring voltage

### 409-06 Overhauling Induction Motors

When you complete this lesson, you will be able to describe and properly execute each of the steps necessary to the induction motor overhaul process.

• List preliminary steps taken before starting any motor disassembly
• Explain how to disconnect the motor leads
• Describe the various steps of motor disassembly and inspection
• Identify tests that may be conducted on the rotor and stator
• Explain how to reassemble the motor and prepare it for service

### 409-07 Generator System Heat Protection

When you complete this lesson, you will be able to discuss industry standard heat reduction methods for industrial AC power generation, including hydrogen cooling systems and their associated equipment.

• Explain why a hydrogen cooling system is a preferred option for operating with AC power generators
• List three properties of hydrogen which make it the efficient gas to use for industrial generator cooling purposes
• Describe how a generator is purged of hydrogen gas using carbon dioxide gas
• Identify hydrogen monitoring systems commonly found in power generation facilities
• Discuss why a seal oil system is required for a hydrogen-cooled generator
• Identify the parts of a stator cooling system commonly found in power generation facilities
• Define the term isolated-phase bus and discuss steps to cool it

### 409-08 Generator Overhaul

When you complete this lesson, you will be able to discuss the steps taken in shutting down the generator, preparing a generator for maintenance, and considerations when conducting the overhaul inspection.

• Describe preparations for generator shutdown that ensure safe working conditions
• Discuss why some systems need to continue to operate after generator shutdown
• Explain the process of purging the hydrogen from the generator
• Describe stator component inspection
• Describe rotor component inspection
• Identify some of the electrical testing conducted on the generator

### 409-09 DC Motors and Generators

When you complete this lesson, you will understand how DC generators and motors convert energy from one form to another. In addition, you will be able to describe basic DC generator and motor winding configurations, and identify uses of each type.

• Outline the process of DC voltage generation
• Describe the windings and connections associated with a DC generator
• Describe the windings and connections associated with a DC motor
• Explain how various types of DC generators operate
• Discuss DC motor theory
• Identify and describe various types of DC motors

### 409-10 Maintenance of Direct Current Motors and Generators

When you complete this lesson, you will be able to describe the basic components of a DC motor and a DC generator, and be prepared to conduct basic maintenance and inspections of each.

• Identify the windings and connections of a DC generator using generator drawings
• Identify the windings and connections of a DC motor using motor drawings
• Explain some problems commonly found with brushes and commutators
• Describe the basics of commutator and brush maintenance for DC generators and motors
• Identify items to be checked as part of regular maintenance and inspections