National Electrical Installation Standards

Standards as High as Your Own

?
Monday, February 17, 2020

Question:

Hello, regarding smoke detectors and fire dampers on ducts. I have always connected them and seen them connected with FMC or BX cable because the duct could move or is not rigid, so I am looking for clarification. I was reading the IBC recently and came across "909.12.2 Wiring". In addition to meeting requirements of NFPA 70, all wiring, regardless of voltage, shall be fully enclosed within continuous raceways. The commentary reads "Wiring is required to be placed within continuous raceways, which provides an additional level of reliability for the system. The definition of the term “raceway” in NFPA 70 lists several acceptable types of complying raceway that can be used; however, manufactured cable assemblies such as metal-clad cable (Type MC) or armored cable (Type AC) are not included".

No one has said anything to me before, but you know how it goes, you don’t know until someone opens a can of worms...

Camilo Rodriguez

A

Answer:

NOTE: All responses to questions submitted to the Code Question of the Day are answered at face value.

Hi Camilo, thanks for the question.

If Section 909.12.2 requires continuous raceways then that is the type of wiring method that is required to be used. AC Cable and MC Cable are cable assemblies and are defined in Section 320.2 and 330.2 respectively. The term raceway is defined in Article 100 as "An enclosed channel designed expressly for holding wires, cables, or busbars, with additional functions as permitted in this Code." The Articles covering raceways are provided in Chapter 3.

ABOUT CQD: The Code Question of the Day (CQD) is NECA and ELECTRICAL CONTRACTOR Magazine’s flagship National Electrical Code (NEC®) public forum for the industry, sponsored by EATON. The daily distribution of Q&A generates a lively dialogue and shares relative Code-based practical responses.

SUBMIT YOUR CODE QUESTION: Click here to submit a question to for inclusion in an upcoming edition of the Code Question of the Day, or email codequestion@necanet.org

CHARLIE TROUT: 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. Even though Charlie passed away in October of 2015, his work continues in spirit. NECA continues to maintain this question forum for its many subscribers in memory and recognition of all his significant contributions to making the NEC what it is today.

NECA STANDARDS: NECA publishes the National Electrical Installation Standards™ (NEIS™), a series of ANSI-approved performance and quality standards for electrical construction. NEIS can be purchased in the NECA Store in three formats: a printed or PDF download of a standard or, as an annual subscription service.

NECA SAFETY PRODUCTS & PUBLICATIONS: NECA produces electrical safety publications and products for the industry including jobsite safety guides, handbooks and resource kits. View a full listing of available resources and products »

IMPORTANT NOTICE: Unless the question requests a response based on a specific edition, all answers are based on the latest edition of NFPA 70® National Electrical Code®.

This correspondence is not a formal interpretation of the NEC® and any responses expressed to the questions are opinions and do not necessarily represent the official position of NECA, NFPA, the NEC Correlating Committee any Code-making panel or other electrical technical committee. In addition, this correspondence is neither intended, nor should it be relied upon, to provide professional consultation or services. 

UPDATE YOUR SUBSCRIPTION PREFERENCES: Subscribe or Unsubscribe from this list.