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

Articles in Industry Publications

Trade press article

Heed design letters when replacing motors

  • November 2016
  • Number of views: 7108
  • Article rating:

By Mike Howell
EASA Technical Support Specialist

Too often, replacement specifications for three-phase squirrel-cage induction motors cover only basic nameplate data such as power, speed, voltage, and frame size, while overlooking other important performance characteristics such as the design letter. This can lead to misapplication of a motor, causing poor performance, inoperability, or failures that result in unnecessary downtime. To avoid these problems, familiarize yourself with the following speed-torque characteristics and typical applications for design letters that NEMA and IEC commonly use for small and medium machines (up to about several hundred kilowatts/horsepower).

  • NEMA Designs A and B, IEC Design N
  • NEMA Design C, IEC Design H
  • NEMA Design D


Comments are only visible to subscribers.