IEC VS NEMA
The motor standards are grouped in two major categories: NEMA and IEC.
North America the National Electrical Manufacturer's Association (NEMA) defines motor standards.
In most of the rest of the world these standards are defined by the International Electrotechnical Commission (IEC).
Like NEMA, IEC establishes and publishes mechanical and electrical standards for motors.
Many IEC standards have been somewhat nationalized. For example, Germany has its VDE 0530 standard, Great Britain has its BS 2613 standard and France has NF CS1-100. But they parallel IEC 34-1 standards.
Though NEMA and IEC standards use different terms, they are essentially similar in ratings and, in most cases, are interchangeable. NEMA standards tend to be more moderate - allowing more room for “design interpretation.” IEC standards on the other hand, tend to be more specific and more categorized.