408.41 Grounded Conductors

[LarryFine]

Agreed, see my edit to post number 10.

Okay, now that the picture is clear, is it okay that the 3-to-1 neutral joint is employed for the purpose of reducing the required number of neutral bus holes?

If so, is it okay that the three breaker handles are not tied, since the joint is obvious, that the shared pigtail is used, and which three circuits are sharing it?

Unlike a typical MWBC, with white wires joined in a J-box, anyone having a reason to open this particular connection would see the three associated black wires.

 

[JFletcher]

Okay, now that the picture is clear, is it okay that the 3-to-1 neutral joint is employed for the purpose of reducing the required number of neutral bus holes?

If so, is it okay that the three breaker handles are not tied, since the joint is obvious, that the shared pigtail is used, and which three circuits are sharing it?

Unlike a typical MWBC, with white wires joined in a J-box, anyone having a reason to open this particular connection would see the three associated black wires.

For question number one, my answer is yes. For question number 2, although it is obvious, I would have to say no, with the notation that I would have to look extremely carefully at the language requiring multiwire branch circuit breakers to be handled tied. I don't know the code section, I do not know the language or if there are any exceptions, however my gut tells me no matter where that multiwire branch circuit is created or delineated into Branch circuits, the breakers would have to be handle tied.

 

[ActionDave]

I agree. It does not say that those grounded conductors must be continuous or unbroken from conduit or cable entry to neutral bar.

It doesn't say each grounded conductor except for the ones you use a wago on......

It says EACH GROUNDED CONDUCTOR shall terminate in an individual terminal that is not also used for another conductor.


It doesn't say each grounded conductor except for the ones that you don't think should be included...

It doesn't say each grounded conductor except for the ones that need to be spliced..,

It says, plainly and clearly,

Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

 

[JFletcher]

It doesn't say each grounded conductor except for the ones you use a wago on......

It says EACH GROUNDED CONDUCTOR shall terminate in an individual terminal that is not also used for another conductor.


It doesn't say each grounded conductor except for the ones that you don't think should be included...

It doesn't say each grounded conductor except for the ones that need to be spliced..,

It says, plainly and clearly,

Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

By definition, a multiwire branch circuit only has one grounded conductor*. Delineating those into branch circuits can happen in the cabinet, or a junction box.

*Edited to add, except where parallel runs of 1/0 or larger are used. Not applicable to Larry's installation.

 

[infinity]

1) Okay, now that the picture is clear, is it okay that the 3-to-1 neutral joint is employed for the purpose of reducing the required number of neutral bus holes?

2) If so, is it okay that the three breaker handles are not tied, since the joint is obvious, that the shared pigtail is used, and which three circuits are sharing it?

3) Unlike a typical MWBC, with white wires joined in a J-box, anyone having a reason to open this particular connection would see the three associated black wires.

1) It's permitted to make a MWBC with 3 circuits if all three are on different phases. By splicing all three neutrals with one pigtail to the neutral bus you would be doing just that, creating a MWBC. A handle tie or multi-pole CB would then be required for the three circuits.

2) Handle tie or multi-pole CB required for MWBC's.

3) J box or cabinet it doesn't really matter where you create the MWBC the MWBC rules would still apply.

 

[wwhitney]

In the arrangement proposed in the OP, I'm not convinced that the jumper contained entirely within the panelboard is part of the branch circuit. The definition of "branch circuit" doesn't address the issue one way or the other. So I'm not convinced that using a jumper in this fashion creates an MWBC.

To expand on this, suppose you run out of terminals on the neutral bar in a panelboard enclosure. You could handle that in any of these ways:

1) Mount another terminal bar in the enclosure, insulated from the case, and run a jumper to the first neutral bar.
2) Within the panelboard enclosure, use a multi-port connector (wago, polaris) to connect several branch circuit grounded conductors to a jumper to a terminal on the neutral bar.
3) Same as (2), but with a single-port connector (wirenut).
4) Install a junction box next to the panelboard enclosure, splice together the branch circuit grounded conductors there, and run a single grounded conductor into the panelboard enclosure.

I'm convinced that (1) does not create an MWBC while (4) does. (2) and (3) are not so clear.

Cheers, Wayne

 

[LarryFine]

Someone gets my drift. I would make a slight change in the wording of #2 (and 3):

2) Within the panelboard enclosure, use a multi-port connector (wago, polaris) to connect three branch circuit grounded conductors to a jumper to a terminal on the neutral bar.
3) Same as (2), but with a single-port connector (wirenut).

The jumper in #1 would have to be sized for the maximum current imbalance, while that in #2 and #3 can be circuit size; in my case, #12. Every three neutrals could be done the same way.

This is similar to a residential panel upgrade where the original neutrals don't reach the new neutral bar, and are paired together with single jumpers of the larger gauge (if mixed) to the bar.

I've also used three-conductor cables to extend existing circuits to a new panel. I've never used tied breakers for these. What was done in the J-boxes or old panel would be instantly obvious.

 

[infinity]

You must create a MWBC, you cannot splice a few neutrals together and then use a larger single conductor to go to the neutral bar. This is permitted in 225.7(B) for outdoor lighting but not for branch circuits in a panel.

200.4 Neutral Conductors. Neutral conductors shall be installed in accordance with 200.4(A) and (B).
(A) Installation. Neutral conductors shall not be used for more than one branch circuit, for more than one multiwire
branch circuit, or for more than one set of ungrounded feeder conductors unless specifically permitted elsewhere in this Code

225.7 Lighting Equipment Installed Outdoors.
(A) General. For the supply of lighting equipment installed outdoors, the branch circuits shall comply with Article 210 and 225.7(B) through (D).
(B) Common Neutral. The ampacity of the neutral conductor shall not be less than the maximum net calculated load current between the neutral conductor and all ungrounded conductors connected to any one phase of the circuit.

 

[kwired]

Are grounded conductors terminated within panelboards?

The enclosure is not part of the panelboard, is the grounded conductor terminal bar part of the panelboard?

Grounded conductors connected together with a wire nut within a panelboard enclosure are not terminated within the panelboard.

Cheers, Wayne

yes, if you take the panelboard assembly out of the cabinet, the grounded conductor assembly (almost?) always comes out with it.

While I fully agree the intent of 408.41 is that there be one neutral per hole in the neutral buss that is not what it says.

It says, EACH grounded conductor SHALL TERMINATE within the panelboard in an INDIVIDUAL terminal....

That means shall terminate on the grounded bus terminals in an individual terminal. You can splice all you want in the cabinet. Maybe could use a little better wordsmithing but I believe that is the intent. Now if you bring two or three together like mentioned by OP and create a MWBC, you have one neutral for that branch circuit to terminate on the neutral bus - common trip breakers or handle ties also will be required on the MWBC.

But the panelboard is technically within a cabinet so the splices are made in the cabinet not the panelboard.

Correct.

We're talking about three single-phase 120v home runs that enter the panel individually, where each hot wire lands on a single-pole breaker, and the three neutrals are joined together so only one neutral-bus terminal is required.

This is electrically identical to a typical three-phases-plus-a-shared-neutral "full boat" except the neutrals are joined in the panel, rather than in a junction box where one neutral would accompany the three hot wires in a conduit.

They are joined in a cabinet that happens to house the panelboard. They are not joined in or on the panelboard. And again yes you have now created a MWBC and must use common trip breakers or handle ties.

 

[infinity]

They are joined in a cabinet that happens to house the panelboard. They are not joined in or on the panelboard. And again yes you have now created a MWBC and must use common trip breakers or handle ties.

This is the part that is confusing because of how 408.41 is written, "within the panelboard" surely sounds like if it's inside of the panel in your basement then they must terminate on the neutral bus. Certainly not the intent and what does "within the panelboard" even mean? :?

408.41 Grounded Conductor Terminations. Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

 

[kwired]

This is the part that is confusing because of how 408.41 is written, "within the panelboard" surely sounds like if it's inside of the panel in your basement then they must terminate on the neutral bus. Certainly not the intent and what does "within the panelboard" even mean? :?

As I said it could maybe use a little better wordsmithing, but per NEC definition you can't really splice "in a panelboard" you could splice "on a panelboard".

The splices in question are spliced in a cabinet and the resulting common neutral of the created MWBC is landed "on" the panelboard neutral bus.

 

[wwhitney]

No one has responded to my point that the definition of Branch Circuit doesn't specify where the branch circuit starts on the grounded conductor(s).

If I assert that the jumper used in any of my cases (1) through (3) is not part of the branch circuit but is an extension of the feeder feeding the panel, the definition doesn't contradict that. Is there any other language in the NEC to contradict that assertion?

Cheers, Wayne

 

[infinity]

No one has responded to my point that the definition of Branch Circuit doesn't specify where the branch circuit starts on the grounded conductor(s).

If I assert that the jumper used in any of my cases (1) through (3) is not part of the branch circuit but is an extension of the feeder feeding the panel, the definition doesn't contradict that. Is there any other language in the NEC to contradict that assertion?

Cheers, Wayne

Not sure that I follow. If you have 2-12/2 cables entering the panel and land each hot leg on a CB and splice the neutrals together with a pigtail to the neutral bus you must create a MWBC, meaning that each breaker is on a different phase. The code sections are in post #28.

 

[Russs57]

An open POCO neutral can make all circuits MWBC in ground Z is high enough.

 

[kwired]

No one has responded to my point that the definition of Branch Circuit doesn't specify where the branch circuit starts on the grounded conductor(s).

If I assert that the jumper used in any of my cases (1) through (3) is not part of the branch circuit but is an extension of the feeder feeding the panel, the definition doesn't contradict that. Is there any other language in the NEC to contradict that assertion?

Cheers, Wayne

The branch circuit, when talking about the grounded conductor, I would assume starts wherever you connect to the feeder conductor, the neutral bus in the panel is an extension of the feeder conductor, but I don't know many inspectors would allow you to run say a 8AWG jumper from neutral bus then splice multiple branch circuit conductors to it and call it an extension of the feeder. Might work but just don't see it being accepted by many. Now if said jumper is same size as the branch circuits connected to it and you arrange it only one conductor per "phase" you have created a NEC defined MWBC, in that case it is not an extension of the feeder it is the common neutral portion of the MWBC.

 

[wwhitney]

Not sure that I follow. If you have 2-12/2 cables entering the panel and land each hot leg on a CB and splice the neutrals together with a pigtail to the neutral bus you must create a MWBC, meaning that each breaker is on a different phase. The code sections are in post #28.

The above statement assumes that the pigtail is part of a branch circuit. If I instead call the pigtail a feeder, then there is no MWBC.

Cheers, Wayne

 

[readydave8]

What was done in the J-boxes or old panel would be instantly obvious.

I agree
But if "instantly obvious" worked, we might not need all those handle ties anyway

Or black marking on white conductor in romex when hooked to single pole switch

 

[infinity]

The above statement assumes that the pigtail is part of a branch circuit. If I instead call the pigtail a feeder, then there is no MWBC.

Cheers, Wayne

Not sure how you go from branch circuit to a feeder, what you described does not meet the definition of a feeder.

 

[kwired]

Not sure how you go from branch circuit to a feeder, what you described does not meet the definition of a feeder.

It gets a little tricky as the definitions mostly were written for the sake of the ungrounded conductors, IMO. There is no overcurrent protection on the grounded conductors and the line between feeder and branch circuit for the grounded conductor becomes more blurry.

 

[JFletcher]

The above statement assumes that the pigtail is part of a branch circuit. If I instead call the pigtail a feeder, then there is no MWBC.

Cheers, Wayne

With all due respect, I disagree. Feeders are on the line side of the final ocpd.

The above cited 200.4 precludes wire nutting together two or more neutrals from the same leg and running a single wire to the neutral bar, regardless of if it is sized for the load. it would most likely also violate the conductors of the same circuit must be in the same raceway, as well as paralleling wires that are smaller than 1/0.

If the neutral is for ungrounded conductors of opposite legs, or phases for 3 phase, it is a multiwire branch circuit by definition. I do not see being able to call your neutral jumper a feeder because of its proximity to the panel board.