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EASA's private webinars

Displaying 11 - 15 of 54 private webinars available

DC Theory

This webinar describes, in practical terms, how a DC motor works. Working with basic principles of attraction-repulsion and magnets, the operation of a DC machine is explained without mathematical formulas. Some of the principles to be explained include:

  • the role of interpoles
  • armature coil pitch
  • the interaction of fields and armatures to create rotational torque
  • interpole polarity
  • brush neutral
  • compound-wound fields
Who should attend

Those involved in electric motor repair, from entry level to 30+ years of experience, will benefit from attending this session. Hands-on technicians, supervisors and sales personnel, as well as those who use DC machines, will learn from this webinar.


Topic(s): DC

DC Theory and Design 101

This webinar will cover:

  • Video animation of a DC motor
  • Attraction / repulsion explanation as magnets
  • Ampere-turns of armature, fields, interpoles
  • Determining the correct interpole circuits
  • Evaluation of armature designs
  • How to recognize opportunities for improvement
Who should attend

This webinar is intended for supervisors, winders and those desiring to learn more about DC machines.


Topic(s): DC, Theory & design

Dealing with Shaft and Bearing Currents

This session will address key issues related to shaft and bearing currents in electric motors and generators. Critical topics that will be covered include recognizing symptoms of shaft and bearing currents, and determining if damaging current levels are present. Also, possible causes of the damaging current, such as machine dissymmetry and operation on variable frequency drives (VFDs) will be dealt with. Methods of testing to confirm the presence of shaft or bearing currents will be described, as well as how to assess the magnitude of the damaging currents. Further, solutions to eliminate or control shaft and bearing currents, such as insulators, isolators, and ceramic bearings, will be offered.

Who should attend

This seminar will be most useful for service center and field technicians with at least 5 years experience, service center managers, engineers, or anyone with previous experience dealing with shaft and bearing current issues looking to expand their knowledge.


Topic(s): Bearings, Root cause failure analysis, Shafts

Drilling Down Into DC Design

This one-hour webinar will focus on:

  • How to use basic design rules to verify data for fields, interpoles and armatures
  • Verifying the correct armature coil pitch
  • Special cases where you can improve on the original armature design
  • What to do when the armature was received stripped, and the manufacturer no longer exists

Topic(s): DC, Theory & design

Drop Testing of Fields and Synchronous Poles: Tips to Interpretation

This session will cover the basics of drop testing, as well as offer tips for interpreting the results. Both the AC and DC drop test methods will be described as well as the advantages and drawbacks for each. For those cases where the drop test results are out of tolerance, this material will guide the technician in determining the reason for the variation—how to recognize the difference between shorted coils and differences in iron, airgap or other influences. Rewind and assembly tips will also be discussed, where they influence the results of a drop test.

Who should attend

This seminar will be most useful for service center and field technicians with at least 5 years experience, service center managers, engineers, or anyone involved in DC motor or generator repair, as well as those who are simply looking to expand their knowledge.


Topic(s): DC, Testing

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