Product Manual

CHAPTER VI
Metric (IEC) Designations and Dimensions
The International Electrotechnical Commission (IEC) is a European-based
organization that publishes and promotes worldwide mechanical and
electrical standards for motors, among other things. In simple terms,
it can be said that IEC is the international counterpart to the National
Electrical Manufacturers Association (NEMA), which publishes the motor
standards most commonly used throughout North America.
Dimensionally, IEC standards are expressed in metric units.
IEC / NEMA Dimensional Comparison
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* Shaft dimensions of these IEC frames may vary between manufacturers.
** Horsepower listed is closest comparable rating with similar mounting
dimensions. In some instances, this results in a greater HP rating than
required. For example, 37 kW 4 pole converts to 50 HP but nearest
HP rating in the NEMA frame having comparable dimensions is 75 HP.
OBSERVE CAUTION if the drive train or driven load is likely to be
damaged by the greater HP.
Equivalent HP can be calculated by multiplying the kW rating by 1.341.
Multiply HP by .7457 to convert HP of kW.
To convert from millimeters to inches multiply by .03937.
To convert from inches to millimeters multiply by 25.
NOTES