IEC vs ANSI Switchgear – Understanding the Global Standards

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Worldwide there is an increasing demand for companies to leverage their global footprint to drive efficiencies, improve processes and reduce costs. In the electrical engineering realm, this creates many complications. Each country has its own rules, regulations and standards, which do not necessarily align. This highlights the importance of understanding and bridging the gap between standards to properly design and coordinate an electrical system.

In the U.S. and in the rest of the world, there are two prevailing standards bodies: the International Electrotechnical Commission (IEC) and the American National Standards Institute (ANSI). ANSI is the prevailing standard in North America and some select regions, while IEC prevails in much of the rest of the world. Each takes a different approach to developing and approving standards which drastically affect the design and testing of equipment. For instance, the legal and liability environment in North America drives some minimum criteria for design, installation and performance, leading to ANSI standards being closely tied in with building and safety codes. This allows certain oversight and inspection to take place. Since IEC is applicable worldwide, across many countries where local practices, codes and legal environments vary drastically, the standards are more performance-based. Some regions may follow more strict requirements compared to the IEC standards ― for instance in the United Kingdom ― while other regions may only comply with select portions of the IEC standard. Neither standard is better or worse, but understanding the differences in each region is critical when designing and specifying equipment.

When applying equipment out of its typical region, here are a few topics to consider when selecting equipment designed by different standards.

1. ANSI is a design-based standard, while IEC tends to be a performance-based standard.
a. ANSI standards can specify sheet metal thickness, paint color, barriers and other features to ensure consistency of equipment from various manufacturers. This means that most manufacturers’ equipment designed to the same standard vary little from one another. IEC standards dictate the intent of the design, and to what test or environment the design must comply. For instance, the standard may specify a degree of compartmentalization, but how this is achieved in design may vary by product or manufacturer. This means manufacturers of IEC equipment are more free to innovate in their equipment, while complying to the same testing and performance requirements.

2. Electrical testing and ratings between IEC and ANSI are not necessarily the same or equivalent. IEC equipment may not pass the equivalent ANSI test, and vice versa, due to these differences.
a. A good example is with temperature rise testing, where there are some contacts which have the same ratings, while others may have a higher or lower temperature restriction.

switchgear, ANSI, IEC Temperatures

b. Enclosure types also do not compare apples-to-apples. NEMA ratings used with ANSI equipment do not compare directly to IP ratings in IEC.

ANSI NEMA and IEC Enclosure types

Cannot be used to convert IEC Classification Designations to NEMA Type Numbers

Considering these differences, it’s difficult to imagine that there are globally accepted products. Companies like Schneider Electric have made great strides in being a truly global provider of electrical equipment and energy management systems, and there are global products available. Such examples are Schneider Electric’s Motorpact Medium Voltage MCC, GHA Gas-insulated Switchgear, and Premset’s Shielded Solid Insulation System (2SIS), which are both ANSI tested, third-party validated by UL and are also available as IEC products globally. The key is understanding that each product may be slightly modified or have different available ratings based on the requirements and applicable standards for each region in which it is being applied.


To learn more about Bridging the Gap between IEC and ANSI standards, watch the on-demand webinar.


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