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 Library

Article

Understanding motor temperature rise limits

  • November 2003
  • Number of views: 12459
  • Article rating: 4.0

Tom Bishop, P.E. 
EASA Technical Support Specialist 

How do we know if a motor is operating within its temperature rating? The simple answer, and a good one, is that the National Electrical Manufacturers Association (NEMA) has defined temperature rise for electric motors in Motors and Generators, NEMA standard MG 1-1998. In this article we will focus on temperature rise and tem­perature sensing of three-phase induction motors. 

We will begin by identifying some key terms. Temperature rise is the increase in temperature above ambient. Ambient temperature is the tempera­ture of the air (or other cooling medium) in the area surrounding the motor, frequently termed “room temperature.” The sum of the ambient temperature and the temperature rise is the overall, or “hot,” tem­perature of a component. Insulation temperature classes are based on the overall temperature. For ex­ample, a Class B winding system is rated 130ºC. The normal maximum ambient, per NEMA, is 40ºC. The temperature rise limit for the Class B winding would be estimated at 90ºC (130-40). 

LOGIN TO VIEW AND DOWNLOAD THE ARTICLE



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 May 2024
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