Routing of single phase neutral to disconnect

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JUSTEINEE

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I have a situation where a single phase 277VAC circuit is being routed from a panelboard to a load. The conduit exits the panelboard and is routed along the ceiling. We have a disconnect that is mounted approximately 5 feet below the conduit run is routed along the ceiling. The contractor has dropped a single conduit to the disconnect and has only routed the ungrounded "hot" conductor to the disconnect along with an equipment grounding conductor.

My question is does the neutral need to be routed with the phase conductor to the disconnect. I know that the neutral would serve no purpose but i have always had it in my mind that all of the circuit conductors have to be routed together. The code section i would fall back on is 300.5 (I) in the 2017 version of NEC.

The thing that has me wondering is i know on lighting circuits it has been standard practice to not route a neutral to the light switch (code now requires a neutral or the ability to add a neutral).

What are your guys thoughts? Please provide code references so that I can do further research.
 
IMO the reasoning for the rule you mentioned is to reduce EMF effects around the conductor(s).

In your case you do have a simple switch loop for the most part. You have current flowing one way to the disconnect and simultaneously same current level the opposite direction as it leaves the disconnect - EMF's cancel.

Only time you would need neutral to this switch is if you actually had a load at the switch or beyond the switch via a different path.

Need for grounded conductor at certain switch locations that was added in more recent years has to do with common use of occupancy or other automatic switching devices that may need that grounded conductor. Possibly a questionable rule to require such if there is no load to connect to that grounded conductor but this is not one of the places that requires that anyway.
 
If both ungrounded conductors are in the same raceway, then it is just a switch leg set up like commonly used for lights as you described earlier.

The noodle would not need to be routed to the disco.

The required noodle for common light switche boxes was mandated for future use of devices that may require one like many occupancy sensors.

edit: kwired types faster.:)
 
Thanks guys. The common sense of these comments is what i was thinking as well but i am not sure how it fits with the code i referenced.

"all conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors shall be installed in the same raceway or cable or shall be installed in close proximity in the same trench."

I don't think the installation will cause any issues and we have years of installations with lighting that prove that but can I ignore the above code reference or does is simply not apply or perhaps there is an exception somewhere else in code.

So i guess in its simplest form i know its safe but is it wrong.
 
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