Facebook Twitter LinkedIn YouTube Menu Search Arrow Right Arrow Left Arrow Down Arrow Up Home Arrow Next Arrow Previous RSS Icon Calendar Icon Warning Icon
Resourcesbreadcrumb separatorResource Library

Filter the results

  • Enter one or more words to find resources containing any of the words entered
  • Enter words or phrases between " " to find exact match
SearchClear

Resource Library

Article

Replacing vintage variable speed drives with VFDs

  • April 2004
  • Number of views: 3002
  • Article rating: 1.0

Jim McKee (deceased)
Alabama Electric Motor Service

The ability to vary the speed of our prime movers has always been desirable. Electric motors are no exception. Many designs and types of motors have been developed over the years to fill this need for variable speed. The most widely used and successful designs include the direct current motor, eddy current coupling/ motor combination, three-phase shunt commutator motor (brush shifting or Schrage motor), and various mechanically variable devices such as adjustable pitch pulleys and cone/ wheel combinations.

EASA service centers often find it desirable or necessary to replace one of these vintage variable speed devices. There are many reasons for replacing older drives; they include improved efficiency, unavailability of repair parts and high maintenance costs. 

A properly sized Variable Frequency Drive (VFD) /three-phase induction motor combination is often the right choice for the new drive.

LOGIN TO VIEW AND DOWNLOAD THE ARTICLE



EASA Technical Manual

More information on this topic can be found in EASA's Technical Manual
  • Section 5: Electronics

Related Reference and Training Materials

Related articles

Categories: Drives/controls
Tags: Variable frequency drives
Rate this article:
1.0
Print

PREVIOUS ITEM
Comments are only visible to subscribers.

Getting The Most From Your Electric Motors

Getting The Most From Your Electric Motors - coverThis 40-page booklet provides great advice for obtaining the longest, most efficient and cost-effective operation from general and definite purpose electric motors.

This booklet covers topics such as:

  • Installation, startup and baseline information
  • Operational monitoring and maintenance
  • Motor and baseline installation data
  • How to read a motor nameplate
  • Motor storage recommendations

LEARN MORE AND DOWNLOAD MÁS INFORMACIÓN Y DESCARGAR BUY PRINTED COPIES

READ MORE ABOUT THE FEATURES AND BENEFITS

EASA/AEMT Rewind Study

EASA Rewind Study cover

The Effect of Repair/Rewinding on Premium Efficiency/IE3 Motors
Tests prove Premium Efficiency/IE3 Motors can be rewound without degrading efficiency.

DOWNLOAD THE FULL RESULTS

ANSI/EASA AR100-2020

ANSI/EASA AR100-2015 cover

Recommended Practice for the Repair of Rotating Electrical Apparatus
This is a must-have guide to the repair of rotating electrical machines. Its purpose is to establish recommended practices in each step of the rotating electrical apparatus rewinding and rebuilding processes.

DOWNLOAD - ENGLISH

DESCARGAR - ESPAÑOL

EASA Technical Manual

EASA Technical Manual cover

Revised September 2022
The EASA Technical Manual is the association's definitive and most complete publication. It's available FREE to members in an online format. Members can also download PDFs of the entire manual or individual sections.

VIEW & DOWNLOAD