NEMA Naming and Codes

American Plugs and Sockets

Many people have trouble understanding the NEMA (National Electrical Manufacturers Association) pattern and numbering system as allocated to the US power connectors – available to purchase from our e-shop in the Mains Connectors section. The code is comprised of four major identifiers, in a combination of numbers and letters which can appear more like alphabet soup than a structured electrical specification.

However there is a simple way to decode plug patterns and connections, making locating the correct specification dead easy.

  • The first identifier, which is either a blank space or an “L,” indicates whether the plug is a straight or locking blade device – if there is an “L” it is a locking connector.
  • The second identifier is a number which assigns the voltage rating; for example, a “5” represents a voltage rating of 125 Vac and a “6” denotes a rating of 250 Vac. The rating given is the highest voltage allowed for the device. Other voltage ratings are described below.
  • The third identifier, also a number, identifies the highest amperage rating allowed for use with the device.
  • The fourth and final identifier is a letter that determines whether the device is a plug (“P”) or a receptacle / outlet / socket (“R”).

Putting that all together into a quick reference chart produces the following:

You can view a larger version in your browser.

Leads Direct makes great efforts to provide accurate and complete information. However, portions of the information contained in this website and any documents viewed on it or downloaded from it may be incorrect or not current. Any errors or omissions should be reported for investigation and correction. The information provided in any documents whether on our website or otherwise is provided "as is." No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given.

Related Items

Responsive website designed & developed by