408.41 Grounded Conductors

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jaggedben said:
The requirement for feeder neutrals is to carry the unbalanced current or to meet table 250.122, whichever is larger. As long as you do that, I think the question is what code section has been violated. If you don't meet those size requirements, then you've violated 200.4(A).
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Still comes down to where is the line drawn between feeder and branch circuit when it comes to the grounded conductor.

When I was first in this trade the guy I worked for used to run say 3 #12 ungrounded (on 120/240 single phase) and a #10 neutral. This back when there were almost no handle tie rules. I can remember a few times even putting a neutral bar (on insulating mounts) in a junction box and running say a #6 or even #4 neutral and several ungrounded conductors that all utilized that neutral. A new inspector stopped us from continuing this practice - and we realized it never really was code compliant after pointing out the code(s) that applied. Again this before there was much for handle tie rules which today is just one more section of code to cite. None of those installs ever burned down that I am aware of. Some I know are still there. Main thing is that it is not a proper MWBC, though it may function just fine.
 
Let me ask some questions then:

Would it change anything if the language said "onto a panel board" instead of "within a panel board"?

Can a panel board compliantly exist outside of an enclosure?

Does the article 100 definition of a panel board include its enclosure?


Do any panel boards, i.e. the guts of the panel, have a separately mounted neutral lug going to its own terminal bar, or are they all one piece? In other words, could you remove the feeder lugs and breaker buses without at the same time removing the neutral lugs or terminal bar?

If the answer to the above question is yes, like in a three phase panel for a 3 wire delta system, are there any factory kits to convert that into a 4-wire wye?

Finally, if you are permitted to do the installation as you propose, what is the exact name of that jumper, and what code article determines its size?
 
JFletcher said:
Let me ask some questions then:

Would it change anything if the language said "onto a panel board" instead of "within a panel board"?

Can a panel board compliantly exist outside of an enclosure? See 408.38

Does the article 100 definition of a panel board include its enclosure? NO


Do any panel boards, i.e. the guts of the panel, have a separately mounted neutral lug going to its own terminal bar, or are they all one piece? In other words, could you remove the feeder lugs and breaker buses without at the same time removing the neutral lugs or terminal bar?

If the answer to the above question is yes, like in a three phase panel for a 3 wire delta system, are there any factory kits to convert that into a 4-wire wye?

Finally, if you are permitted to do the installation as you propose, what is the exact name of that jumper, and what code article determines its size?
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I still think the answer here is better wording is needed in NEC as the definitions we do have kind of take more consideration of the ungrounded conductors of a feeder and not the grounded conductor. Without better wording we end up with case by case code enforcement and use of AHJ/inspector judgement if such conditions arise.
 
This thread has been fun to read, mainly seeing where each person's mind takes the basic question.

I'm still in the position that whether the neutral bus is part of the panel-board is not relevant. It came installed in the panel, and does not have enough terminal ports to suit the number of breaker spaces. When I first opened the panel, there were still 12 empty breaker spaces, and there were several neutral terminals with two or three white wires in them.

The wire-nut vs Polaris argument is interesting, saying that the individual terminals makes a difference as to whether this is a MWBC. Anyone who would disturb either connection would have to associate the white to the black to make sure they have the correct breaker; I'm saying that the wire-nutted connection being right there makes the handle tie moot.

Rather than follow suit and land my three new whites in already-used holes, I chose to combine them into a single #12 wire, which is large enough since each new breaker is on a different phase. I did have to combine two existing whites into another hole to free up the hole I used. I admit that doubling up existing white wires was also non-compliant.

I realize the only real solution would be to add another neutral bar, and since this is a M/L panel, it must be insulated. Supposing I chose that route, what if there is no manufacturer's accessory bar, and there is no space for it on the neutral lug? I would have to mount it and use a wire jumper to the existing neutral bar. What size wire, a full 200a gauge?

I'm merely admitting that I did not add a handle tie when I installed the three new circuits. Again, these are three individual 2-wire 120v circuits, on three new adjacent breakers. I had the option of adding more wires to already-used bus terminals, or joining them to make one wire. Which would be worse? Does 6" of jumper really make a difference?

Just curious: does anyone know what year the every-MWBC simultaneous-disconnect rule came into being?
 
LarryFine said:
This thread has been fun to read, mainly seeing where each person's mind takes the basic question.

I'm still in the position that whether the neutral bus is part of the panel-board is not relevant. It came installed in the panel, and does not have enough terminal ports to suit the number of breaker spaces. When I first opened the panel, there were still 12 empty breaker spaces, and there were several neutral terminals with two or three white wires in them.

The wire-nut vs Polaris argument is interesting, saying that the individual terminals makes a difference as to whether this is a MWBC. Anyone who would disturb either connection would have to associate the white to the black to make sure they have the correct breaker; I'm saying that the wire-nutted connection being right there makes the handle tie moot.

Rather than follow suit and land my three new whites in already-used holes, I chose to combine them into a single #12 wire, which is large enough since each new breaker is on a different phase. I did have to combine two existing whites into another hole to free up the hole I used. I admit that doubling up existing white wires was also non-compliant.

I realize the only real solution would be to add another neutral bar, and since this is a M/L panel, it must be insulated. Supposing I chose that route, what if there is no manufacturer's accessory bar, and there is no space for it on the neutral lug? I would have to mount it and use a wire jumper to the existing neutral bar. What size wire, a full 200a gauge?

I'm merely admitting that I did not add a handle tie when I installed the three new circuits. Again, these are three individual 2-wire 120v circuits, on three new adjacent breakers. I had the option of adding more wires to already-used bus terminals, or joining them to make one wire. Which would be worse? Does 6" of jumper really make a difference?

Just curious: does anyone know what year the every-MWBC simultaneous-disconnect rule came into being?
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Is this a service panel with some of the neutral spots terminating EGC's? Those can be moved to a separate EGC bar if needed and free up some spots for neutral conductors.

"wire-nutted connection being right there makes the handle tie moot" - handle tie is about as moot IMO for a "split wired" receptacle that is immediately adjacent to the panel, but it is still a MWBC and code wants handle ties on all MWBC's.

If it were my installation and not being inspected - I probably double up some connections. If being inspected - really depends on exactly what there is to work with and what is available - as well as what the inspector may or may not accept.
 
kwired said:
Is this a service panel with some of the neutral spots terminating EGC's? Those can be moved to a separate EGC bar if needed and free up some spots for neutral conductors.
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No, as stated above, it's a 3ph M/L panel, G.E. brand, plug-on breakers, in a commercial strip-mall. The EGC's already have their own bus bolted to the panel and with the feeder EGC landed in a lug.

"wire-nutted connection being right there makes the handle tie moot" - handle tie is about as moot IMO for a "split wired" receptacle that is immediately adjacent to the panel, but it is still a MWBC and code wants handle ties on all MWBC's.
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If the three circuits entered the panel as a MWBC, I would have used a handle tie and never asked the question. That's why I stated in the other thread that I knew that I was being a bad boy.

If it were my installation and not being inspected - I probably double up some connections. If being inspected - really depends on exactly what there is to work with and what is available - as well as what the inspector may or may not accept.
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It is not being inspected, but I felt, and still feel that my option was the lesser of two evils. I will try to remember to take a pic of the inadequate neutral bus when I go back later this week.
 
I could be wrong.. but i think it needs to be read as a complete sentence. There are no commas or bold type. Unless there's something saying you can't splice a neutral in a panel I would think splicing 3 neutrals to one neutral and that one single neutral terminates within the panelboard in an individual terminal..

Each grounded conductor (doesn't say entering the panelboard ) shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

Lets say, your splicing a neutral in that panel that you don't want to go to the neutral. Because of 408.41 you would HAVE TO terminate this splice on the neutral bar ? And if so, could they be in one terminal or would it have to be two terminals?

I can see how it could read all grounded conductors, but I can also read it as each that are to enter a terminal.
 

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LarryFine said:
No, as stated above, it's a 3ph M/L panel, G.E. brand, plug-on breakers, in a commercial strip-mall. The EGC's already have their own bus bolted to the panel and with the feeder EGC landed in a lug.


If the three circuits entered the panel as a MWBC, I would have used a handle tie and never asked the question. That's why I stated in the other thread that I knew that I was being a bad boy.


It is not being inspected, but I felt, and still feel that my option was the lesser of two evils. I will try to remember to take a pic of the inadequate neutral bus when I go back later this week.
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There is your biggest problem :D
 
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JFletcher said:
Let me ask some questions then:

Would it change anything if the language said "onto a panel board" instead of "within a panel board"? No. (I feel like it should read 'within the panelboard enclosure'.)

Can a panel board compliantly exist outside of an enclosure? No, but the enclosure is not part of the panelboard, and the enclosure may contain other devices besides the panelboard.

Does the article 100 definition of a panel board include its enclosure? NO.

Do any panel boards, i.e. the guts of the panel, have a separately mounted neutral lug going to its own terminal bar, or are they all one piece? Yes. MOST of the panelboards I encounter are separate from the neutral bar. That is, the neutral bar is mounted to the enclosure separately from the rest of the guts. In other words, could you remove the feeder lugs and breaker buses without at the same time removing the neutral lugs or terminal bar? YES

If the answer to the above question is yes, like in a three phase panel for a 3 wire delta system, are there any factory kits to convert that into a 4-wire wye? Possibly. There are certainly different sizes of neutral bars available as replacement parts for most ordinary 'load centers'. Note, they are often sold as 'load centers', not panelboards. A 'load center' (not a code term) typically consists of an enclosure, a panelboard, and an (often) separate neutral bar.

Finally, if you are permitted to do the installation as you propose, what is the exact name of that jumper, and what code article determines its size? Feeder. 215.2
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LarryFine said:
... Supposing I chose that route, what if there is no manufacturer's accessory bar, and there is no space for it on the neutral lug? I would have to mount it and use a wire jumper to the existing neutral bar. What size wire, a full 200a gauge?

...
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That would probably be the most prudent, although many neutrals are oversized. I feel like if you used a Polaris and used all of the available terminals, then you could probably use a smaller wire (i.e. sized for the unbalanced load or to 250.122, which probably gives you a 6awg). But I can see that argument going either way.
 
LarryFine said:
This thread has been fun to read, mainly seeing where each person's mind takes the basic question.

I'm still in the position that whether the neutral bus is part of the panel-board is not relevant. It came installed in the panel, and does not have enough terminal ports to suit the number of breaker spaces. When I first opened the panel, there were still 12 empty breaker spaces, and there were several neutral terminals with two or three white wires in them.

The wire-nut vs Polaris argument is interesting, saying that the individual terminals makes a difference as to whether this is a MWBC. Anyone who would disturb either connection would have to associate the white to the black to make sure they have the correct breaker; I'm saying that the wire-nutted connection being right there makes the handle tie moot.

Rather than follow suit and land my three new whites in already-used holes, I chose to combine them into a single #12 wire, which is large enough since each new breaker is on a different phase. I did have to combine two existing whites into another hole to free up the hole I used. I admit that doubling up existing white wires was also non-compliant.

I realize the only real solution would be to add another neutral bar, and since this is a M/L panel, it must be insulated. Supposing I chose that route, what if there is no manufacturer's accessory bar, and there is no space for it on the neutral lug? I would have to mount it and use a wire jumper to the existing neutral bar. What size wire, a full 200a gauge?

I'm merely admitting that I did not add a handle tie when I installed the three new circuits. Again, these are three individual 2-wire 120v circuits, on three new adjacent breakers. I had the option of adding more wires to already-used bus terminals, or joining them to make one wire. Which would be worse? Does 6" of jumper really make a difference?

Just curious: does anyone know what year the every-MWBC simultaneous-disconnect rule came into being?
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to think that all this time I 5hought of an MWBC as solely being a circuit that has more than one live wire sharing the neutrals and the grounds from the panel to the outlets and that if you supply a neutral for each live wire it is no longer an mwbc....
 
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