Code Question

Can anyone provide me with a reference? I’m on an inspection and haven’t had the opportunity to look this up yet.

What section/reference requires all conductors of a single circuit to be contained within a single conduit?

Thanks in advance.

300.3 Conductors

• (B) Circuit Conductors Grouped Together.
All conductors of a circuit must be installed
in the same raceway, cable, trench, cord,
or cable tray, except

Thanks Mike.

There is an exception for circuits run in non-metallic methods.

Yes, I know. This was in two runs of side-by-side PVC, buried and supplying the pool equipment panel about 60 feet away.

I had never seen this done before, so I wanted to check the reference before I left the property. One PVC contained 1 ungrounded conductor and the neutral, while the other PVC contained the other ungrounded conductor and the EGC.



That is also a violation of 300.20(A).

To shed light on my ingonrance, with the exception of it not being code, what is the potential concern with running the wires in that manner?

The magnetic fields will cause heating.

I read that, but didn’t believe that to be at issue.

This was new construction, and the electrical inspector “assured” me this is acceptable after I questioned it. Based on the exception of 300.3, I conceded. After all, he does have the last word.

I didn’t think 300.20 was at issue because the conductors don’t really “travel through” separate metallic enclosures. I guess I can see the potential for a small portion of the box to become heated.

So (Robert and Jim), do you guys see this as an improper installation?

I would not do it this way and never thought about this before. I believe this meets the exception in 300.3. As far as 300.20, once the conductors enter the enclosure they could be considered grouped. I would like to hear other opinions on this.

You’re correct I quoted the wrong section It should be 300.20(B). 300.3(B)(3) directs you to 300.20(B).

Robert, as I understand 300.20 it would apply to things like K&T entering a metallic junction box or enclosure.

Yes, but 300.3(B)(3) sends you to 300.20(B) which, in the case of the photo, would require a slot to be cut between the raceways. Since in the photo you have conductors run in different raceways then the provisions of 300.20(B) would apply.

After reading both together I agree a slot is needed.

Yes it’s a bit confusing because when you read 300.20(B) as a standalone requirement it doesn’t seem to fit the installation in question. Once you add 300.3(B)(3) into the mix it directs you to the requirement for a slot.

Well, I guess I missed that one :smiley:

But it was very educational :slight_smile:
Thanks for the question Jeff and thanks Jim and Robert for the thinking and code reading process to reveal the answer!