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Hots moved to subpanel without their neutrals

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11K views 43 replies 15 participants last post by  MHElectric  
#1 ·
Sorry about the lame picture. This is a subpanel mounted directly adjacent to the main service panel in a home. Several branch circuits were moved to this sub panel by having the ungrounded conductors routed from the service panel to breakers in this subpanel. The neutrals for the moved branch circuits were left connected to the neutral bar in the service panel. Is this allowed? The picture is lame because I did not show the connections to the circuit breakers but each is active. And you can see only two neutrals on the neutral bar. There is a separate ground bar.
Image
 
#5 ·
I am not sure. Forget what article it is, but there is something that says you have to have both the neutral and hot in the same enclosure entrance if it's metal or else you have to cut vent holes or some such nonsense. I'm sitting on the throne right now and I'll be here for a while so someone else will probably help.
 
#6 ·
Is this allowed?
Nope.

300.3 Conductors.

(B) Conductors of the Same Circuit. All conductors of
the same circuit and, where used, the grounded conductor
and all equipment grounding conductors and bonding conductors
shall be contained within the same raceway, auxiliary
gutter, cable tray, cablebus assembly, trench, cable, or
cord, unless otherwise permitted in accordance with
300.3(B)(1) through (B)(4).
 
#11 ·
We have a similar rule to 300.3 up here in the north. basically, if putting a
clamp meter around a group wires would result in a current being indicated,
that group of conductors shouldn't pass through anything which current will
be induced into, such as an EMT conduit or metal connector or locknut, or...
you get the idea.
Neatly wired though.:thumbup:
P&L
 
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#14 ·
There is an exception in the NEC for INDUSTRIAL panel boards -- that allows the neutral bar to stay in a gutter above the narrow body of the panel board.

This specific design permitted said panels to nestle within the channel of major I beam verticals.

ONLY said listed panel boards are permitted this exemption.

( BTW the gutter above is connected to the panel board by a vertical gutter -- Tee style -- such that the hot feeders and the returning branch hots are passing right by each other. Hence, there is no Ohmic heating// unbalanced flux. )

It's the ONLY exception I know of.

Since this is a residence, it's against the Code... even though this fella followed in the spirit of the industrial scheme.

( Smells like an industrial electrician whipped this together. )

Think of the follow on confusion as the DIYer // handy man can't begin to figure out what's up.
 
#15 ·
I don't see all of those provisions necessary:

300.3(B)(4) Enclosures. Where an auxiliary gutter runs between a
column-width panelboard and a pull box, and the pull box
includes neutral terminations, the neutral conductors of circuits
supplied from the panelboard shall be permitted to
originate in the pull box.
 
#26 ·
telsa, it seems like very few people actually read your posts here. Myself and one other gentleman did, we both found that it was very inaccurate. I even posted the code article showing that you were wrong on multiple accounts, but in a polite way.

Since then, all you have done is attacked myself and the other gentleman.

What you posted is wrong, the code I posted is straight from the NEC and clearly shows why. What more needs to be said?
 
#30 ·
Thanks for the link, that was awesome :laughing:

So have you taken college level quantum physics???

:thumbup:

"It's no different than a switch loop, electrically speaking."

In a switch loop you don't need the neutral because the current is flowing back on the other leg of the loop (as it normally would with a neutral) and therefore canceling out whatever effect heats the metal.

I did it installing a generator subpanel at my house.
Those are switch loops so what I said above applies. You won't have the heating in that situation either.
 
#43 ·
I believe that the neutral is to originate in the same panel that the circuit originates. The article explaining slots being cut crossways on panel knockout is for the magnetic effect on ferrous pipe runs where parallel conductors of one phase are run in one conduit. Usually only done on a humongous service where it makes it easier to keep parallel wires the same identical length. I can also say I have seen factory wired panels for residential generator backed circûits where they have you splice in the original panel.i know most people don't splice the neutral as well. Fast and dirty they make these generator installs. I believe that it's a violation as well. The magnetic effect is only an issue when you have one phase in one pipe. Kind of like a transformer winding ratio on the conduit.
 
#44 ·
Funny, I have run into this type of installation on several occasions, and I don't think the thought of whether it was code or not ever crossed my mind. I just thought it was a different way to skin the cat.

Thanks to Don for showing up with the actual code article. Otherwise I would have just continued on like always.