National Electrical Installation Standards

Standards as High as Your Own

Tuesday, February 19, 2019


Re: CQD answer published Thursday, January 31, 2019 - Wire Terminations

1) Charlie, I believe the question for CQD, 1-31-2019 is referring to WAGOS. They are listed for both solid and stranded wires according to the information on the package. Tom Ekstrom

2) Hi Charlie, product spec for RTRT is also interesting in regards to the question about stranded versus solid wire under "lug nuts", even though the submitter did not specify the product he was talking about. Terminals of the wire-binding screw, setscrew, or screw-actuated back-wired clamping types are suitable for use with both solid and stranded building wires. Have a great day. Greg McMurphy

3) IMHO all mechanical electrical connections are "pressure connectors" regardless of how the "pressure" is created & maintained. Crimped connections maintain continued "pressure" on the elastic deformation of metal(s). Obviously, this excludes soldered or otherwise similar metallurgical joints.  Perhaps the definition in Article 100 can be more definitive (discriminating). Incidentally, you need to be complimented on the excellent job (service to the industry) you are doing giving continuity to what Charlie Trout started. R. Schneider, P.E.

4) What is meant by an upturned lug in 110.14 (A)? Josh Vinesett



Hey all y'all, thanks for your comments and the kind words.

1) Instructions on product packages can be very helpful and must be followed as stated in 110.3(B). Not all termination types are suitable for both solid and stranded wire.

2) You did the research on product spec we were hoping for. The specific type of terminations you mention are suitable for both solid and stranded wire.

3) Correct, crimped, set screw, wire binding screws are all examples of pressure connectors (Connector, Pressure) as that term is defined in Article100.

4) An upturned lug is typically used do describe a termination with the surface the conductor is placed on (plate) is bent upwards at the corners. A screw is usually provided that is used to secure the conductor.

ABOUT CQD: NECA’s Code Question of the Day (CQD) is a leading National Electrical Code® forum for NECA and the industry. The CQD generates a lively dialogue and relative practical and Code-based responses to an ever-increasing and interactive audience.

IMPORTANT NOTICE: All answers are based on the latest edition of the National Electrical Code®, unless the question requests a response based on a specific edition. This correspondence is not a formal interpretation of the NEC®. Any responses expressed to the questions are opinions and do not necessarily represent the official position of NECA, NFPA, or any technical committee. In addition, this correspondence is neither intended, nor should it be relied upon, to provide professional consultation or services.

ABOUT CHARLIE: Charles M. Trout, better known as Charlie, was a nationally known NEC® expert and author. He served on several NEC® technical committees and is past chairman of CMP-12. In 2006 Charlie was awarded the prestigious Coggeshall Award for outstanding contributions to the electrical contracting industry, codes and standards development, and technical training. Charlie was also a member of NECA’s Academy of Electrical Contracting. Charlie’s experienced team of industry experts keep the CQD dialogue and discussions active and informative in the spirit of the man himself, as he wanted.

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