National Electrical Installation Standards

Standards as High as Your Own

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Wednesday, January 16, 2019

Question:

Can I run a class 2 circuit cable (outer sheath around insulated conductors) in same conduit as power based on 725.136(I)(2)?

Thanks, Zach

A

Answer:

Hey Zach thanks for your question. As you know Class 2 circuit cables and conductors cannot be in the same raceway with power conductors as stated in 725.136(A) - unless allowed by 725.136(B) through 725.136(I). A 2 inch separation is required between Class 2 conductors and power conductors as stated in 725.136(I) - unless allowed by (1) or (2). The 2 inch distance is removed if the Class 2 conductors are permanently separated from the power conductors by a continuous firmly fixed nonconductor such as porcelain tubes or flexible tubing in addition to the conductor insulation itself. Notice that the wording in (2) is between conductors, not between cables. So, if the AHJ considers the cable sheath to be a "firmly fixed nonconductor" they can allow the installation you are describing. Make sure you check with them before not after you do this.

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