At the Interpower Group of Companies, we have real people answering the phones. No recorded messages. As a result, we receive a number of interesting product design questions. Usually if a question has been asked by one person, it means that others also have the same question. So to assist you, we will be sharing a few of the commonly asked questions, complete with answers. Be sure to follow our series, “Interpower’s Answers to Commonly Asked Questions.”

Question: 
Why can’t I use a NEMA 5-15 power cord in other countries?

Key points:

• NEMA 5-15 is rated for 125V, not 250V
• Using this in a 220V application can be dangerous

Answer:
Ron Barnett, Product Development Manager, explained the purpose of a NEMA 5-15 power cord.

“First of all, the NEMA 5-15 is intended for use in North America. The NEMA Nomenclature used by UL and CSA states that a NEMA 5-15 be used only up to 125 volts. The ‘5’ signifies the voltage rating, but more specifically the voltage configuration. If you wish to use a North American plug that is UL and/or CSA approved at 250 volts, you will need to use a different configuration other than the standard NEMA 5-15, such as the NEMA 6-15,” Barnett explained.

Barnett acknowledged that some countries, such as the Philippines who have not yet standardized their electrical regulations, allow the use of the NEMA 5-15 at 220VAC, but companies need to be cautious with this. He emphasized that companies shipping equipment should use due diligence in testing the power cord to make sure there are no safety issues involved by using it at 220V.

NEMA (National Electrical Manufacturers Association) has set standards so that consistency and safety can be achieved. A system has been set up to standardize the description and rating of plug and socket patterns.

The first number determines the voltage level:

• A “1” identifies that the configuration is rated at 125 volts, Class II (ungrounded);
• A “5” identifies that the configuration is rated at 125 volts, Class I (grounded);
• A “6” identifies that the configuration is rated at 250 volts, Class I (grounded).

The second number is a system of identifying the amperage ratings: 15 to 60 amps.

• The letter at the end of the number refers to a plug or receptacle (P=plug, R=receptacle).

The “L” at the beginning of a number refers to a locking configuration.

For example:

• L5-20P—Locking, 125V, Class I, 20A plug
• 1-15R—125V, Class II, 15A receptacle

To see a list of the NEMA configurations, see Interpower’s chart Connect to North America.

If you have other questions, Interpower offers free technical support. You can check the website at www.interpower.com, e-mail sales@interpower.com (United States) or uk@interpower.com (United Kingdom) or contact Customer Service in the United States at (800) 662-2290 or in the United Kingdom at +44 (0)1908 295300.

If you have ideas for future InfoPower blogs, please e-mail infopower@interpower.com.