Concerning NEC Cable Tray Art. 392, wanted to make sure that it is OK to install single & multiconductors (all 600V and below) in same tray as long as sizing requirements for each have been followed and added to obtain correct overall tray size. Presume there also is no requirement for a barrier between the multi and single conductors. Appreciate any help.
Multiconductors, Single Conductors & Cable Tray
- Thread starter bozo
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I will attempt to clarify my question. In reading the tray sizing requirements of Art. 392, I was left wondering if it is acceptable to install both single conductors and multiconductors in the same tray (as long as the respective sizing requirements for each type have been followed). To use a specific example, can 480V #4/0 single conductors (TC rated, of course) be installed in the same tray with 120V 4/C#12 multiconductors. Maybe this is a "no-brainer" and the answer is an obvious "yes", but statements such as in 392.6(E)("Multiconductor cables rated 600 volts or less shall be permitted to be installed in the same cable tray.") make me wonder. It doesn't say "Multiconductor cables and single conductor cables--". Logically, I would think that as long as the different types of cables have the appropriately sized dedicated space in the tray, they could occupy the same tray. However, I'm not sure if my interpretation matches the intent of the NEC.
Afraid I still have to remain neutral on the matter... not because of the detail level of your query, but rather the lack of explicit NEC requirements for mixing multi- and single conductor cables in the same tray, as you so noted.bozo said:
What I can tell you is that I have mixed them before... but they were industrial installations under direct EE supervision.
Since you only mentioned sizing, don't forget to make the required ampacity adjustments of 392.11.
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