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

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

Resource categories

Resource Library

My motor failed. Now what?

  • June 2016
  • Number of views: 2293
  • Article rating: No rating
Trade press article — Maintenance Technology

Process downtime is expensive—even more so when it’s unexpected. So, when an electric motor fails, we tend to pull, repair, or replace it, and move on as quickly as possible. In doing so, however, we may miss an opportunity to capture basic information that could help improve the reliability of the application. With a little planning, these data can be gathered with no delay in startup.

Safe starting of motors: Pay attention to temperature increase

  • May 2014
  • Number of views: 1139
  • Article rating: 5.0

The most stressful time for electric motors is during starting. At starting, the motor current is the highest it will ever be. This is referred to as starting or locked rotor current. These different terms describe that when the shaft speed is zero, the current is maximum. Once the motor has been successfully started, the load current level is reached and the cooling circuit of the motor is able to dissipate the additional heat produced by the starting current. Restarting the motor before this additional heat has been dissipated means more heat in the form of kW•h will be added on top of that which is there. Each subsequent start before the additional heat has been dissipated will add more heat — raising the temperature until some component in the motor reaches its failure point. This article looks at safe starting practices for electric motors.

Squirrel cage motors: Three most common starting methods

  • May 2013
  • Number of views: 1442
  • Article rating: 5.0

The most common method of starting squirrel cage three-phase motors is across the line (direct-on-line). Some applications require limiting the motor starting current and/or torque to reduce the stress on the electrical and mechanical systems. Although there are other methods such as autotransformer, reactor and using a variable frequency drive (VFD), the focus in this article will be on the reasons behind the selection of the three most common methods of achieving these objectives. Specifcally, these methods are part winding, wye-delta, and electronic soft-starting. The windings in all three of these methods usually have 6 leads.

Motor starting capabilities and considerations

  • September 2007
  • Number of views: 829
  • Article rating: No rating

It should not be assumed that because a motor can drive a running load, it also has the capability to accelerate the load up to rated speed. During starting, a motor must deliver the energy required to accelerate the load. To do this, the motor torque must exceed that needed to accelerate the load. The motor torque value in excess of the load torque requirement is termed the "torque available for acceleration."

Comparing differences in wye-delta and part-winding-start connections

  • February 2001
  • Number of views: 1542
  • Article rating: 5.0

One of the most misunderstood winding connections is the part-winding start. Many customers (and some members) tend to blur the differences between the part-winding-start (PWS) connection and wye-start, delta-run connections.

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



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.


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.



EASA Technical Manual

EASA Technical Manual cover

Revised May 2021
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.