Matthew Conville, P.E.
EASA Technical Support Specialist

When we consider putting a machine into service, we must consider the duty rating of the machine. If we do not, there is a good chance that the machine being placed into service will have thermal degradation of the windings. Not every application is created equal. For example, a crane motor doesn’t need the same duty rating as a punch press motor that runs continuously, even though they may have the same horsepower ratings. Likewise, a chop saw motor wouldn’t need to have the same duty rating as a pump motor where the pump is operated continuously.

Topics discussed are:

• NEMA MG1-1.40 and IEC 60034-1, 4
• Turndown ratio
• "S" ratings
• Questions to consider

LOGIN TO VIEW AND DOWNLOAD THE ARTICLE