300.20 violation

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That's a good question. IMO, I would also say yes because they are not in contact with each other. Hopefully someone else will weigh in
 
Put one cable tie loosely around the wires and then, even if not touching they are grouped.
(For those cases. like MWBCs, where wires are required to be grouped for identification in the panel enclosure.)
 
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I say no. Your good to go.
That is not an enclosure, it is a panel. Also they are grouped at the entrance. Part of the code is for pipe, wireway, enclosures(box).
Looks pretty but I leave the circuits together (per breaker) makes tracing them easier.
 
rnatalie said:
A panel is not a raceway.
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and all the conductors of each circuit are inside the same enclosure.

The intent of this rule is to not create induced current in ferrous raceways or enclosures, having all conductors of a circuit inside the raceway or enclosure leaves the magnetic effects of the conductors canceling one another when it comes to effects on the enclosure.

I would rather group all conductors of each circuit together myself, but don't see anything wrong with this other than neutrals of MWBC's would need to somehow be identified as to which ungrounded conductors they go with, but even that would only be required if there is multiple MWBC's in an individual raceway or cable but could be done with tagging/marking/etc.
 
petersonra said:
It appears to me they are grouped together.

I don't see any indication of undesirable heating.

I think it is ok.
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They are, but not all conductors of a circuit are bundled in same bundle, which could be a small improvement. Still isn't going to have any significant effects on the ferrous enclosure in this case, all conductors of all the circuits are contained within the enclosure.
 
rnatalie said:
A panel is not a raceway.
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The Nec says enclosure or raceway. How can a panel not be an enclosure?

300.20 Induced Currents in Ferrous Metal Enclosures or
Ferrous Metal Raceways.
(A) Conductors Grouped Together. Where conductors carrying
alternating current are installed in ferrous metal enclosures
or ferrous metal raceways, they shall be arranged so as to avoid
heating the surrounding ferrous metal by induction. To accomplish
this, all phase conductors and, where used, the grounded
conductor and all equipment grounding conductors shall be
grouped together.
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What is the meaning of grouped.
Yes, a panel is in an enclosure, what distance must be maintained to be grouped?
 
sameguy said:
What is the meaning of grouped.
Yes, a panel is in an enclosure, what distance must be maintained to be grouped?
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There is no distance consideration. The problem only occurs if the ferrous material does not surround all of the conductors.
 
I think grouped means all going through the same knockout hole. Once everything is in the box they don't need to stay together. I can not open the photo at the top and can only see it inline. I was hoping to see what knockouts each cable went through but that isn't in the photo. If each conductor of a given branch circuit or feeder are all in the same knockout hole, including its equipment ground, I think it is compliant.
 
sameguy said:
What is the meaning of grouped.
Yes, a panel is in an enclosure, what distance must be maintained to be grouped?
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You are missing the point that if all conductors of the circuit are within the ferrous enclosure (whatever it may be) their magnetic fields cancel one another and results in having no effects on the enclosure. In this case grouped means all conductors need be within said enclosure. Most the time it would apply to ferrous raceways, but still would apply to ferrous wireways, junction boxes or cabinets (which is what the enclosure of a panelboard is).
 
sameguy said:
See #6 post, didn't miss a thing.
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Grouped to prevent inductive effects in the enclosure means nothing more than all the conductors must be within the enclosure. Run just one of them outside and you now have inductive effects on the enclosure, may not be much effect but is still unbalanced magnetic fields within.
 
I think that some of the confusion comes from the word "grouped" in the requirement. The NEC provides no guidance as to what grouped actually means therefore some common sense needs to be applied. As I stated early there is a lot of electrical equipment that has the conductors separated by enormous lengths, often feet and they are not problematic.

I was told by an apprentice that a teacher in his apprentice school said that due to 300.20 you cannot untwist the conductors in MC cable when they enter the panel until they get to the circuit breaker. :oops:
 
Panelboards at times only have 1 neutral bar on one side. So if the rule were applied too literally, nothing would be acceptable. I think an understanding of the reason for the rules might help. 300.20 deals with magnetic heating of ferrous metal conductor enclosures (meaning electrical enclosures and raceways) and the associated fire hazards. Other sections (300.3B, 376.20, 392.20C&D just to name a few) have to do with concerns over the increased reactance that is present when conductors of the same circuit are separated over a long distance, and the increased risk of overcurrent protective devices not functioning properly as a result.

Sometimes, it's easy to find a bunch of similar NEC sections, and think they are all trying to mitigate the same risk. 300.20 is its own section because it is trying to deal with the unique risk of induced current from imbalance if only partially contained in a metal raceway or enclosure. Other NEC sections, though worded to require similar grouping, are written to deal with other risks.

300.20 is one of the sections that tells you the goal of the rule: it is to avoid heating.
300.3B does not have anything stating the goal of the rule.

If there is a modification to the NEC to reduce the possibility of improper interpretation of 300.20, perhaps the real solution would be to add a statement to 300.3B, so that it states that the conductors shall be grouped so as to reduce circuit impedance and facilitate overcurrent protective devices. Then, it could go on with its language about grouping in the same tray, conduit, trench, etc.

Hope I'm not called out by one of the better experts here as wrong.............
 
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