iKNOW AC/DC Motor Maintenance

This lesson was designed to provide training for electricians, mechanics, and others, wanting to know more about AC and DC motor maintenance. This library consists of 12 interactive, on-line lessons that address AC and DC motor maintenance. These lessons take approximately 30 to 45 minutes to complete.

Introduction to AC Motor Maintenance


Description: This is the first lesson in the iKNOW™ AC/DC Motor Maintenance Library. The lesson explains the purpose of AC motor maintenance programs and the types of motor maintenance. The lesson also identifies safety procedures that should be used during motor maintenance.

Prerequisites:  None

Topics:

Why Have and AC Motor Maintenance Program?
Three Types of Motor Maintenance
Safety and AC Motor Maintenance

Objectives:

  • Identify characteristics of a motor maintenance program
  • Identify types of motor maintenance
  • Identify safety procedures to use during motor maintenance

Records, Tools, and Instruments


Description: This is the second lesson in the iKNOW™ AC/DC Motor Maintenance Library. The lesson explains the purpose of keeping complete and accurate records using various record keeping formats. The lesson also identifies tools and instruments used for given tasks in motor maintenance.

Prerequisites: Review of the lesson, Introduction to AC Motor Maintenance is recommended.

Topics:

Purpose of Record Keeping
Maintenance Records
Tools and Instruments

Objectives:

  • Identify reasons for having a record keeping system
  • Identify categories of information for a record keeping system
  • Select the appropriate motor maintenance tools and instruments for given tasks

Preventive AC Motor Maintenance


Description: This is the third lesson in the iKNOW™ AC/DC Motor Maintenance Library. The lesson explains aspects of preventive motor maintenance, the steps in inspecting a motor for general maintenance and for identifying problems, and cleaning and lubricating a motor as part of a preventive motor maintenance program.

Prerequisites: Review of the lesson, Introduction to AC Motor Maintenance is recommended.

Topics:

Definition of Preventive Motor Maintenance
Inspection
Methods of Inspection
Cleaning
Lubrication

Objectives:

  • Identify characteristics of preventive motor maintenance
  • Inspect a motor for general maintenance and for identifying problems
  • Clean and lubricate a motor as warranted by a preventive maintenance inspection

Measurement in Preventive AC Motor Maintenance


Description: This is the fourth lesson in the iKNOW™ AC/DC Motor Maintenance Library. The lesson demonstrates the need for taking measurements, and the importance of comparing measurements. Causes and effects of current variations, temperature extremes, and vibration measurements are described.

Prerequisites: Review of the lessons, Introduction to AC Motor Maintenance, Records, Tools, and Instruments and Preventive AC Motor Maintenance, is recommended.

Topics:

Measurement Basics
Current Measurement
Temperature Measurement
Vibration Measurement

Objectives:

  • Explain the need for taking measurements in preventive motor maintenance
  • Explain the importance of comparing measurement readings
  • Take current measurements in preventive motor maintenance
  • Explain the causes of current variation in an AC motor
  • Take temperature measurements in preventive motor maintenance
  • Explain the causes and effects of excessive temperature in an AC motor
  • Take vibration measurements in preventive motor maintenance
  • Explain the causes of vibration in an AC motor

Preparing for Periodic AC Motor Maintenance


Description: This is the fifth lesson in the iKNOW™ AC/DC Motor Maintenance Library. The lesson identifies the characteristics of periodic motor maintenance and the major components of an AC motor. Instruction in testing winding resistance, and winding insulation resistance, as part of pre-maintenance testing is given.

Prerequisites: Review of the lessons, Introduction to AC Motor Maintenance and Records, Tools, and Instruments, is recommended.

Topics:

Introduction to Periodic Motor Maintenance
Major Components of an AC Motor
Pre-Maintenance Testing

Objectives:

  • Identify characteristics of periodic motor maintenance
  • Identify the major components of an AC motor
  • Perform pre-maintenance testing: Winding insulation resistance
  • Perform pre-maintenance testing: Winding resistance

Motor Disassembly and Reassembly in Periodic AC Motor Maintenance


Description: This is the sixth lesson in the iKNOW™ AC/DC Motor Maintenance Library.

Prerequisites: Knowledge of AC motor components is required. Review of the lesson, Preparing for Periodic AC Motor Maintenance is recommended. This lesson teaches the procedures for proper disassembly, cleaning, inspection, and reassembly of an AC motor.

Topics:

Motor Disassembly
Cleaning and Inspection
Motor Reassembly

Objectives:

  • Describe how to properly disassemble an AC motor for periodic motor maintenance
  • Disassemble an AC motor
  • Identify the proper way to clean a disassembled AC motor
  • List the various AC motor parts and what to look for during inspection
  • Describe how to reassemble an AC motor
  • Reassemble an AC motor
  • Describe how to perform post-maintenance testing

Corrective Maintenance for AC Motors


Description: This is the seventh lesson in the iKNOW™ AC/DC Motor Maintenance Library. This lesson discusses causes and corrective actions for various motor malfunctions.

Prerequisites:  Knowledge of AC motor components is recommended.  Review of the lesson, Motor Disassembly and Reassembly in Periodic AC Motor Maintenance, is suggested.

Topics:

Motor Won’t Start
Abnormal Noise
Motor Overheating
Overheated Bearings

Objectives:

  • Identify causes and corrective actions for a motor that wont start
  • Identify causes and corrective actions for a motor with abnormal noise
  • Identify causes and corrective actions for a motor overheating
  • Identify causes and corrective actions for a motor with overheated bearings

Introduction to DC Motor Maintenance


Description: This is the eighth lesson in the iKNOW™ AC/DC Motor Maintenance Library. This lesson introduces participants to DC motors and compares them to AC motors.

Prerequisites: None

Topics:

AC and DC Motor Similarities
Commutator Construction
Commutation

Objectives:

  • Identify similarities between AC and DC motors
  • Identify the difference between AC and DC motors
  • Identify components of a DC motor commutator and their function
  • Identify factors that affect commutation

Commutator Inspection


Description: The ninth lesson in the iKNOW™ AC/DC Motor Maintenance Library, this lesson shows participants how to identify some problems that affect the commutator.

Prerequisites: Knowledge of DC motor components and commutation is recommended.

Topics:

Oxide Film Inspection
High Mica
Uneven Segments
Solder

Objectives:

  • Describe the color of the commutator and explain the function of the oxide film
  • Identify the causes of high mica and corrective actions
  • Identify the causes of uneven segments and corrective actions
  • Identify the causes of thrown solder and corrective actions

Commutator Wear


Description: This is the tenth lesson in the iKNOW™ AC/DC Motor Maintenance Library. This lesson trains participants to recognize friction damage, streaking, threading, and grooving, the cause of these problems, and corrective actions.

Prerequisites: Knowledge of DC motor components and commutator inspection is recommended.

Topics:

Friction
Streaking
Threading
Grooving

Objectives:

  • Identify wear patterns, their causes, and corrective actions
  • Identify the causes of arcing and corrective actions
  • Identify the causes of high mica and corrective actions

Commutator Maintenance


Description: This is the eleventh lesson in the iKNOW™ AC/DC Motor Maintenance Library. The lesson demonstrates the process of preparing a commutator for reconditioning, how to properly cut mica, how to check the commutator after maintenance, and explains the purpose of performing a commutator run-in procedure.

Prerequisites: Knowledge of DC motor components and commutator inspection is recommended.

Topics:

Preparing the Commutator for Reconditioning
Cutting Mica
Commutator Film

Objectives:

  • Explain how to prepare a commutator for reconditioning
  • Explain how to undercut the mica of a commutator
  • Describe how to clean and check the commutator after maintenance
  • Explain the purpose of performing a commutator run-in procedure

Brush Maintenance


Description: This is the final lesson in the iKNOW™ AC/DC Motor Maintenance Library. The lesson describes how to select and inspect brushes. The lesson identifies the procedures for cleaning, inspecting, and setting the height of a brush holder. How to seat brushes and adjust spring pressure is demonstrated.

Prerequisites: Knowledge of DC motor components is recommended.

Topics:

Brush Inspection
Brush Selection
Brush Holder Installation
Seating Brushes
Spring Pressure

Objectives:

  • Describe how to inspect various aspects of a brush
  • Identify the factors to be considered when selecting a brush
  • Identify the procedures for cleaning and inspecting the brush holders
  • Identify the steps involved in setting the height of a brush holder
  • Identify the procedure for installing brushes
  • Explain how to seat brushes
  • Explain how to adjust spring pressure