NEMA and IEC are the two most common standards for power cords used in North America. NEMA connectors are on the side of the power cord that plugs into an AC wall outlet. IEC connectors are the side that plugs into devices like computers or TVs. By and large, NEMA and IEC are compatible with each other. There are many similarities between NEMA and IEC standards, but they are not quite the same.

 

Key Takeaways

 

  • NEMA and IEC are different power-connection standards and systems.
  • NEMA configurations are commonly associated with North American electrical systems.
  • IEC connectors are widely used with electronic equipment internationally.
  • A single power cord can combine a NEMA plug and IEC equipment connector.
  • Always verify the exact connector configuration before purchasing.
  • Check voltage, current, grounding, and equipment requirements.
  • Cable length and connector orientation are important for data centre installations.
  • Do not assume physically similar NEMA or IEC connectors are interchangeable.
  • For international applications, verify the local plug standard and equipment electrical requirements.
  • The correct power cord is determined by the equipment, power source, connector configuration, and electrical specifications.

 

NEMA Connectors

 

 

NEMA is an acronym for the National Electrical Manufacturers Association. Established in 1926, NEMA is an American organization focused on creating, establishing, and promoting safety standards for electrical equipment. Power cords are one of many items that fall under their jurisdiction. Despite being an American organization, NEMA standards are also primarily used in Canada and Mexico as well as parts of Central and South America, nearby small island nations such as Cuba, and some larger countries across the sea like Japan.

NEMA connectors are labeled as two numbers separated by a dash. The first number indicates the voltage rating of the cable; “5” stands for 125 volts and “6” stands for 250 volts. The second number indicates the amperage of the plug. There will also be a letter after the numbers, either a “P” for plug or an “R” for receptacle. For example, a NEMA l5-30p connector will be a plug rated for 125 volts and 30 amps.

 

 

NEMA 5-15P (right) vs. 6-15P (left)

Another standard under NEMA is hospital-grade power cords. The US and Canada have strict standards for power cords used in medical environments. These standards must be followed by law in both countries. Hospital-grade cords have higher safety standards than conventional power cords and are made with enhanced durability.

 

IEC Connectors

 

 

IEC stands for International Electrotechnical Commission. It is a non-profit, non-government organization founded in 1906 that sets international standards on electric and electronic devices. Power cords are one of many devices that fall under their umbrella, specifically IEC 60320. This covers cords that are numbered from C1 to C24, although only a few of these connectors are commonly used throughout the world.

The most common IEC connectors are C13, C15, and C19. C13 is used on household and office electronics such as computers and televisions. C15 is used for devices that generate large amounts of heat, such as electric kettles or small computer networking closets. C19 is used for equipment with higher amperage that requires a constant supply of power, such as data servers or similar rack-mounted hardware.

 

 

From left to right: IEC C13, C15, and C19

Power cords are generally not evaluated as a single item. The connectors and wiring are approved separately. A small number of countries, such as China and Argentina, do approve the whole cord at once but that is the exception, not the rule. Having international standards like IEC connectors makes these evaluations easier from one country to the next.

Because IEC cords are used in different countries with different standards, they do not have universal amperage ratings. For instance, a C13 plug can handle up to 15 amps, which is perfectly fine according to UL (American) standards. But in Europe, the same plug is only approved for up to 10 amps by European regulatory committees. Be sure to check the specs on a cable before buying to make sure it matches the technical requirements of your equipment and legal requirements of your country.

 

Recommendations

 

1. For Computers and Office Equipment

Choose a power cord that matches the equipment inlet, wall outlet, and electrical requirements. Verify the connector configuration rather than selecting a replacement based solely on cable appearance.

2. For Data Centre

Use power cords compatible with the server, networking equipment, rack power distribution unit, and facility power system. Consider connector type, current rating, length, and cable-management requirements.

3. For North American Applications

NEMA power cords are commonly used with North American-style outlets and equipment. Verify the specific NEMA configuration required by the installation.

4. For International Applications

Choose a power cord with the appropriate plug configuration for the destination country and make sure the equipment supports the local voltage and frequency.

5. For Server and Rack Equipment

Check the equipment's IEC inlet and the connector provided by the power distribution system. Select the appropriate cord configuration and length for the rack installation.

6. For High-Density Installations

Consider cable length, connector orientation, and cable-management requirements. Properly selected power cords can help keep rack installations organised.

7. For Replacement Power Cords

Match the replacement cord to the original cord's connector configuration, electrical rating, grounding requirements, and intended application.

8. For Specialized Equipment

Follow the equipment manufacturer's specifications and applicable electrical standards rather than assuming that a physically compatible connector is electrically appropriate.

 

FAQs – Frequently asked questions

 

What is the difference between NEMA and IEC?

NEMA and IEC refer to different standards and connector systems used for electrical power connections. NEMA configurations are widely used in North America, while IEC connectors are commonly used on electronic equipment and in international applications.

What is a NEMA power cord?

A NEMA power cord uses a plug or connector configuration based on NEMA standards. The exact configuration determines its electrical and mechanical characteristics.

What is an IEC power cord?

An IEC power cord uses an IEC connector configuration, commonly on the equipment side of power connections for computers, servers, networking equipment, and other electronic devices.