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Friday, September 30, 2016

Question:

My co-worker said that I'm only allowed to have three current carrying conductors in a pipe no matter what size it is. I personally go by table 310.15 (b)(3)(a) for adjustment factors, I think I can have as much current conductors in a pipe as long we do check tables 310.15 (b)(16) , 310.15 (b)(3)(a) ,Annex C, and Chapter 9 tables am I correct?

Eduardo Morales

A

Answer:

Hey Eduardo thanks for your question. Ask your co-worker to show you the NEC rule that supports their position. It is very common to have "rules" communicated by others but it is important to support them by specific references if possible. The general rule for the number of conductors permitted in raceways is stated in 300.17. The Informational Note directs us to specific NEC sections, usually in the .22 location of the applicable Article. The general rule fo r conductor ampacities is in 310.15. These are separate and different rules but ampacity is related to how many current carrying conductors are in a given raceway. So, yes you are correct if you apply all the rules for the specific installation.

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