The National Electrical Code is the bedrock of the electrical
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NECA and Electrical Contractor magazine are pleased to present their
daily online feature, “Code Question of the Day.”
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Code Question Of The Day
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Thursday, September 02, 2010
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Subject: Switch Loop
Hi Charlie,
Regarding the use of two 2-conductor NM cables to form a 3-way switch loop. I believe that this installation is NOT code compliant, it's a violation of 300.3(B) that requires all conductors of a circuit to be contained within the SAME cable. Both cables are forming the "circuit". Am I missing something in the electrical theory department? I believe that this applies to both 3-way switch loops and also "normal" 3-way switch wiring also.
I look forward to your further explanation, as I look forward to reading this extremely useful column every day.
Thanks,
Gary G.
Electrical Contractor
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code question and answer:
Wednesday, September 01, 2010
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Subject: Enclosures in Wet Locations Above Grade
Charlie,
When 300.9 was added in 2008 it specified that the interiors of above ground raceways installed in wet locations are considered wet locations. Why aren’t enclosures in above ground wet locations included as was done in 300.5(B). It seems to me that the same thought should apply to enclosures installed in wet locations.
Robert Sink
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Answer:
Hey Bob, thanks for participating. I don’t know why enclosures were not specifically included but I believe they should have been. It’s hard to imagine that the enclosure would not be subject the same condensation effects as the raceway.
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Section: 300.9
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Source: Charlie Trout
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NECA is looking for people to join the ANSI approved Canvass method for a new NEIS, NECA 412 Standard for Installing Photovoltaic Power Systems. The scope of the standard is:
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ANSWERS: Answers are the author’s opinions and do not represent formal interpretations of the National Electrical Code.
All answers are based on the latest edition of the NEC, unless the question requests a response based on a specific edition.
CONTACT US: To submit a question, subscribe to Code Question of the Day, or remove yourself from this list, please send an e-mail to
codequestion@necanet.org.
ABOUT THE AUTHOR: Charlie Trout is a nationally-known NEC expert and author. He served on three different National Electrical Code-Making Panels and is past chairman of CMP-12. He is also a member of the NECA Codes & Standards Committee. In 2006 Charlie Trout won the prestigious Coggeshall Award, given to recognize outstanding contributions to the electrical contracting industry in the technical and training area.
NECA STANDARDS & SAFETY PRODUCTS: NECA publishes the National Electrical Installation Standards (NEIS), a series of ANSI-approved performance and quality standards for electrical construction. Visit
www.neca-neis.org for more information. NEIS can be purchased in three formats: as paper books, on CD, or as .PDF downloads.
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