Can't find actual codes against this

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woody75

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Chicago, IL, USA
This question is about shared and parallel neutrals in branch circuits.

I was asked to instal some equipment at my jobsite, but the nearest 120/208 panel was full.* I told the facilities engineer that many of the circuits fed an office, one circuit per desk from back when they had big CAD computers, and many could be recircuited and combined. He said he'd have their maintenence department do it. They did it and i have a hard time accepting what they did.* I need help finding the actual broken codes. I have taken pride in my work and trade for so long that I sometimes forget that quality and craftsmanship isn't always the minimum coded requirement.

What they did was take circuits 1,3, 5, and 7 and spliced them all together with a wirenut in the panel and fed it with the breaker from cir. 1.* So network 1,3,5 (shared neutral and ground) became and joined the A phase (cir 7) of network 7,9,11 (shared neutral and ground.)** Now out in the field, there are 3 circuits (1, 9, 11) sharing 2 parallel neutrals and grounds back to the panel.

So much of what they did seems like butchery to me, but the only actual code violation i could find was about mis-labeled grounded conductors that they never changed.

Out of pride in my work, I almost never:
-split a neutral-sharing network with nonsequential circuits
-use red and blue wires as A phase out of a panel (home runs)
-use wirenuts in a panel or use it as a junction box at all
-walk away without updating labels on devices, wires, and panel schedule
-parallel neutrals or grounds

But again, I can't find a code to REQUIRE any of these with the exception of identifying a grounded conductor to its protected circuit. All of the parallel code applies to feeders, not explicitly to branch circuits.

Thanks for your time.
 
Out of pride in my work, I almost never:
-split a neutral-sharing network with nonsequential circuits

They did not do that, it is now a simple '2-wire' circuit not a Multiwire branch circuit

-use red and blue wires as A phase out of a panel (home runs)

The code does not specify phase colors

-use wirenuts in a panel or use it as a junction box at all

No one does, it is impossible to use a panelboard that way.

But you can, and it is code compliant to splice inside the cabinet containing the panelboard.

See 312.8 and the definition of panelboard in article 100.

-walk away without updating labels on devices, wires, and panel schedule

That could be a violation except did the description really need to change?

-parallel neutrals or grounds

Almost all EGCs run in a steel building are electrically in parallel.

From your description there are no parallel neutrals as the neutrals are not electrically connected at the end away from the panel

I would forget it all and move on, you are not the building owner and unless asked to comment on this other work I would not.
 
If they would have just combined 1,3 and 5 there is no problem.

Adding 7 in there causes issues with handle tie requirements if 9 and 11 are still on their original breakers and 7-9-11 originally were using the same neutral conductor.

It could be further complicated if the original install was made before handle ties were required (do we now need ties? did the breakers supplying a MWBC need to be adjacent to one another before the handle tie rules essentially made it necessary?)
 
If they would have just combined 1,3 and 5 there is no problem.

Adding 7 in there causes issues with handle tie requirements if 9 and 11 are still on their original breakers and 7-9-11 originally were using the same neutral conductor.

It could be further complicated if the original install was made before handle ties were required (do we now need ties? did the breakers supplying a MWBC need to be adjacent to one another before the handle tie rules essentially made it necessary?)

They turned MWBCs into two wire circuits, no handle ties required.
 
They turned MWBCs into two wire circuits, no handle ties required.
On 1, 3 and 5 they did, but tying 7 in with 1,3 and 5 involves the neutral that was originally common to 7, 9 and 11 - should need a handle tie between the new "1", 9 and 11.

Add: or combine 1,3,5, and 7 on the #7 breaker position.
 
I am not sure I fully understand the configuration you are describing.
So network 1,3,5 (shared neutral and ground) became and joined the A phase (cir 7) of network 7,9,11 (shared neutral and ground.) Now out in the field, there are 3 circuits (1, 9, 11) sharing 2 parallel neutrals and grounds back to the panel.
It sounds like you originally had two MWBCs: 1-3-5 and 7-9-11. It also sounds like the loads previously served by 1, 3, 5, and 7 are now getting their power from circuit breaker #1. That much is OK. Finally, it also sounds like circuits 9 and 11 still comprise a MWBC, and that they still share the original neutral. That much is also OK. But I can’t envision what happened to the neutral connection at the receptacle originally fed from circuit 7.

There was a hot wire from circuit breaker 7 that landed on the hot side of a receptacle outlet (call it “receptacle #7”). There was a neutral wire that connected the neutral side of that receptacle to the neutral sides of the receptacle #9 and receptacle #11. From some point along the way, one neutral wire made its way back to the panel’s neutral bus. But if all the wiring changes were done inside the panel, then receptacle #7 still shares its neutral with receptacles 9 and 11. If that is the case, then even if circuit breakers 9 and 11 share a listed handle tie, any future work on one of these circuits would place the worker in danger, because the worker would not know that they also need to turn off circuit breaker #1. You would have a violation of 300.3(B).
 
But if all the wiring changes were done inside the panel, then receptacle #7 still shares its neutral with receptacles 9 and 11. If that is the case, then even if circuit breakers 9 and 11 share a listed handle tie, any future work on one of these circuits would place the worker in danger, because the worker would not know that they also need to turn off circuit breaker #1. You would have a violation of 300.3(B).

I have to disagree with the code cite and the danger you see.
 
I have to disagree with the code cite and the danger you see.
Do you accept that if you turn off the new 7 and the old 9 and 11 breakers the neutral of the former 7-9-11 MWBC may still be carrying current unless you also turn off breaker 1?

Any loads which were originally fed by 7 and returned current on the 7-9-11 neutral are now being fed from breaker 1.

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And putting 1,3,5 and 7 in the orignial #7 spot (assuming it already had a handle tie with 9 and 11) is what should have been done instead of putting them all on breaker #1.

If the install is old enough that handle ties weren't originally required - IDK, probably still a good idea to use position #7 at the very least.
Some AHJ's may make you add a handle tie anyway.
 
And putting 1,3,5 and 7 in the orignial #7 spot (assuming it already had a handle tie with 9 and 11) is what should have been done instead of putting them all on breaker #1.

If the install is old enough that handle ties weren't originally required - IDK, probably still a good idea to use position #7 at the very least.
Some AHJ's may make you add a handle tie anyway.
That would probably be safer, but technically you would also have to identify the 1-3-5 neutral as being part of the 7-9-11 MWBC in the new configuration, yes?
You now have an MWBC that splits off into a "two wire" branch before it ever leaves the panel. Odd, but possibly not against code.

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Do you accept that if you turn off the new 7 and the old 9 and 11 breakers the neutral of the former 7-9-11 MWBC may still be carrying current unless you also turn off breaker 1?


Of course but the changes were made at the panel, there would no point outside the panel that you could break a current carrying neutral associated with the other circuits.

MWBCs are what we do, as often and much as allowed, I am very aware of how to work on them. Been doing so for 25 years before they started requiring training wheels (Handle ties) Before training wheels the circuits would originate from non sequential breakers, neutrals not marked etc. Yet still we manged to not let the smoke out or die. :D
 
Of course but the changes were made at the panel, there would no point outside the panel that you could break a current carrying neutral associated with the other circuits.

MWBCs are what we do, as often and much as allowed, I am very aware of how to work on them. Been doing so for 25 years before they started requiring training wheels (Handle ties) Before training wheels the circuits would originate from non sequential breakers, neutrals not marked etc. Yet still we manged to not let the smoke out or die. :D
It sounds like you have found an easy fix for the OP's concerns then. :)

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From some point along the way, one neutral wire made its way back to the panel’s neutral bus. But if all the wiring changes were done inside the panel, then receptacle #7 still shares its neutral with receptacles 9 and 11. If that is the case, then even if circuit breakers 9 and 11 share a listed handle tie, any future work on one of these circuits would place the worker in danger, because the worker would not know that they also need to turn off circuit breaker #1. You would have a violation of 300.3(B).

This is correct.

Sounds like Original Circuit #7 which is now fed from Circuit #1 is using the neutral from Circuit #9 and #11 out in the field.
If someone was working on the neutral in the panel or a J-Box from circuit #9 and #11 , even with those breakers shut off, and circuit #1 was on and Old Circuit #7 had a load on it. They would catch that load.

It would have been best had they of taken the neutral out in the field for the portion of old circuit #7 and gotten it rerouted to the neutral that originally fed circuits 1,3 and 5.

JMHO

JAP>
 
Do you accept that if you turn off the new 7 and the old 9 and 11 breakers the neutral of the former 7-9-11 MWBC may still be carrying current unless you also turn off breaker 1?

Any loads which were originally fed by 7 and returned current on the 7-9-11 neutral are now being fed from breaker 1.

Sent from my XT1585 using Tapatalk

I would think if you turned off the New #7 which is actually now Circuit #1 (because they tied circuits 1,3,5 and 7 together in the panel) and also turned off 9 &11, there would be no return current from those circuits.

JAP>
 
I have to disagree with the code cite and the danger you see.
Others have already addressed the danger. I cited 300.3(B) as the article being violated because the ungrounded conductors feeding receptacles 1, 3, 5, and 7 are all part of the same circuit now, and they are not in the same conduit. This is presuming (without a confirmation from the OP) that the original two MWBCs (1-3-5 and 7-9-11) were in different conduits.

 
Now out in the field, there are 3 circuits (1, 9, 11) sharing 2 parallel neutrals and grounds back to the panel.


This is the part that confuses me.

If the 2 neutrals were separated in the field to begin with, how did moving old circuit #7 to circuit #1 make 2 parallel paths back to the panel?
9 & 11 would still be returning on their original neutral.
1,3 and 5 would still be returning on their neutral.
7 would be returning on 9&11's neutral.

but I don't see where any circuit is returning on both neutrals?

JAP>
 
This is the part that confuses me.

If the 2 neutrals were separated in the field to begin with, how did moving old circuit #7 to circuit #1 make 2 parallel paths back to the panel?
9 & 11 would still be returning on their original neutral.
1,3 and 5 would still be returning on their neutral.
7 would be returning on 9&11's neutral.

but I don't see where any circuit is returning on both neutrals?

JAP>

Correct. I think it was an error to cite parallel neutrals when shared neutrals was really the issue.
 
Others have already addressed the danger. I cited 300.3(B) as the article being violated because the ungrounded conductors feeding receptacles 1, 3, 5, and 7 are all part of the same circuit now, and they are not in the same conduit. This is presuming (without a confirmation from the OP) that the original two MWBCs (1-3-5 and 7-9-11) were in different conduits.


Not seeing it, the changes were made at the panel each conduit or cable contains all it's associated circuit conductors.
 
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