Understanding Power Mains Across Global Markets

Markets for electrical and electronic equipment are global and more competitive than ever. Companies are no longer just competing with rivals in Los Angeles, Chicago, or Toronto, but also with those in Taipei, Osaka, Munich, and London.

That creates real opportunities. As Bob Wersen, President of the Interpower Group of Companies, put it, product design and tooling are expensive. Designing for a global market helps spread those costs across the widest possible customer base.

The Global Marketplace

Wersen believes that, to sell globally, a number of considerations must be addressed:

• Markings on components, including cords
• National regulations
• Mains plug patterns
• Mains frequencies
• Mains voltages

Most countries have their own type of plug pattern, with current ratings generally ranging from 10 A to 16 A, depending on the specific plug. Global mains voltages range from 100 VAC to 250 VAC, while mains frequencies are either 50 Hz or 60 Hz.

This voltage range is not usually an issue, as universal input power supplies are readily available.

Wersen said: “All of the world’s developed countries and many of the developing countries have electrical safety standards, and most have safety testing agencies.”

A number of countries and regions also have environmental restrictions on substances contained in equipment sold in these areas.

“Some other good reasons for compliance with international regulations include enhanced quality and reliability of the product, meeting your competition head on, and peace of mind in knowing that you sell a product that is not only safe, but one that conforms to international expectations for safety,” Wersen explained.

Companies should conduct in-depth research before deciding to export globally, and it is important to be knowledgeable about the desired country’s import and export requirements.

Global success requires offering products that can be easily adapted to local market needs, without requiring end-user reconstruction. This is especially relevant to power cords, electromagnetic compatibility requirements, and circuit protection.

Any successful domestic marketer would follow this approach in order to ensure the success of its products at home. The same rules also apply in export markets.

Modern customers expect to be able to unpack and use a product immediately, so it is imperative that the product operate at the customer’s input voltage and frequency before it is shipped. A product running at the incorrect frequency or voltage will not be running at its full potential.

Wersen elaborated, “In effect, the world has become a more cohesive market in a global economy. When we talk about ‘international’ today, we mean a world that includes our own domestic market, not just the countries to which we export.”

Power Entry Design for a Globally Accepted Product

A globally accepted product is one that meets both North American and international product safety requirements. These products can be easily adapted to accommodate the different power-entry requirements of worldwide markets.

A number of important differences exist among North American, European, and international standards, each affecting the power-entry design of a globally accepted product.

Plug and Socket Patterns

Plugs and sockets meet an electrical need by connecting electrical equipment to a power source. Numerous plug patterns are used around the world, making this otherwise simple process complicated.

It is important to specify the correct plug and socket to meet the product's requirements when designing electrical or electronic equipment.

Plug patterns vary significantly by country, meaning that manufacturers designing for global markets must determine how to connect to the power supply safely and correctly in each country they export to.

There are also several other considerations regarding plugs and sockets when designing and building a product.

Ratings

A plug and socket have a maximum amperage and voltage rating determined by national and/or international standards. These ratings are set for safety purposes and are typically higher than the actual current measurement in use.

For instance, European voltage is standardized at 230 V, so if a Continental European plug is rated for 16 A at 250 V, it is unlikely that a constant current of 16 A at 250 V will flow through the electrical connection.

The United States’ National Electrical Code sets the standard for common US household use at 120 VAC.

Class I and Class II

Plugs and sockets can be rated for Class I or Class II applications. A Class I application requires grounding, whereas a Class II application does not.

Electrical systems in developing countries may be ungrounded, but it is not advisable to cut off the ground pin to allow a plug to fit into a two-pole, ungrounded socket. This removes the safety ground connection, rendering the plug or socket no longer approved.

It is recommended to use a Class II plug on a power cord or cord set, rather than altering a Class I assembly.

Polarized or Non-Polarized

The term ‘polarized’ can have two meanings in this context: electrical or pin.

Electrical polarization is a standardized method of wiring a plug or socket to circuit wires. Circuit wires must be correctly connected to the line, neutral, and ground contact points on the plug and socket. These components mirror the electrical circuit.

Pin polarization refers to a dedicated alignment of the pins, meaning that there is only one way to fit the plug into the socket. It is important to note, however, that a polarized plug’s pin is not necessarily electrically polarized.

Approvals

The correct plug and socket must be included in the product design, and they must comply with the relevant standard (if applicable) and be in line with those used in the country of export. Most countries require approval documentation for the final product to be accepted.

Choosing the Correct Plug Pattern

It’s important to confirm the country’s current requirements before exporting, as changes may occur at any time.

Strategies for Designing for Compliance

Design a Different Model for Each Set of Safety Requirements

This approach generally involves designing a product model for sale in North America markets, where the voltages are 120 V at 60 Hz, and another model for sale in export markets, where power supply voltages typically range from 100 V to 250 V at 50 Hz.

This approach is attractive in cases where it is not easy to design the power supply to switch between voltage and frequency ratings.

A country-specific strategy with a permanently attached power cord may represent a cost-effective alternative where significant volumes of low-value products are shipped into a single market, for example, supplying hair dryers to Germany.

Design One Model to be Sold in All Markets

This approach allows one single product to be manufactured and sold worldwide, making it an increasingly popular choice for designers and manufacturers.

It is also especially advantageous for North American equipment manufacturers, who currently enjoy the world’s largest homogeneous home market. It is often possible to translate economies of scale into a significant competitive edge in markets where competition is essentially local.

North American Input at 240 V and International Input at 220 V to 240 V

Using a 240 V input for North America and a 220 V to 240 V input for export models will minimize, but not eliminate, differences between North American and export models of higher-current products.

This approach will not remove the need for different power cords, however, depending on the market, it will allow the use of common circuit protection and power supply, provided the power supply accepts both 50 Hz and 60 Hz power.

Europe’s decision to shift to a 230 V electrical distribution system from 220 V and 240 V systems has made this alternative approach more feasible, but this is not an option for equipment with three-phase power inputs because the majority of standard three-phase inputs are 480 V in the United States, 600 V in Canada, and 380 V and 415 V in international markets.

Exporting Products Designed for North America Only

Some manufacturers will export small quantities of products that have already been designed to comply with North American requirements.

It may not be economical to redesign small quantities of product to operate at 220 VAC to 240 VAC and 50 Hz, however. Agency approvals are desirable if these products are to be used in industrial or commercial environments, but they are not essential unless required by law.

In this instance, it is still possible to export a user-friendly product with minimal re-engineering by adding:

• An appropriate cord set or power cord (if the load exceeds 10 A at 220 V)
• An appropriate RFI filter to satisfy European EMC regulations
• An IEC 60320 power inlet
• A circuit protection device

This solution will be sufficient if the power supply operates at 50 Hz, but a 50 Hz-to-60 Hz power supply may be necessary if it operates at 60 Hz.

Power Connections in Developing Countries

There is limited useful information on electrical systems used in developing countries. Where formal electrical standards do exist, they are often ignored in the marketplace or rarely cover plugs and sockets.

Power-generating and distribution systems are also installed at various times by different contractors, meaning these systems may produce power at different frequencies and deliver different voltages for final distribution.

Some cities, and even individual buildings in those cities, may be supplied by two or more generating plants and power distribution systems, with each system delivering a different single-phase voltage and frequency.

Acknowledgments

Produced from materials originally authored by InterPower.

This information has been sourced, reviewed, and adapted from materials provided by Interpower.

For more information on this source, please visit Interpower.