# vertical pathway



## McClary’s Electrical (Feb 21, 2009)

Id day he's right unless you meet the exception


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## Rollie73 (Sep 19, 2010)

I need a copy of the NEC so I can read these articles. 


Wait.....just what I need......more code in my head:no::whistling2:


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## molallaron (Apr 27, 2008)

408.3a3 is referring to switchboards not branch circuit panelboards, or am I drinking my own bathwater


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## 360max (Jun 10, 2011)

408.3 Support and Arrangement of Busbars and Conductors .3 Support and Arrangement of Busbars and Conductors.
(A) Conductors and Busbars on a Switchboard or Panelboard. Conductors and busbars on a switchboard or panelboard shall comply with 408.3(A)(1), (A)(2), and (A)(3) as applicable.
(1) Location. Conductors and busbars shall be located so as to be free from physical damage and shall be held firmly in place.
(2) Service Switchboards. Barriers shall be placed in all service switchboards such that no uninsulated, ungrounded service busbar or service terminal is exposed to inadvertent contact by persons or maintenance equipment while servicing load terminations.
(3) Same Vertical Section. Other than the required interconnections and control wiring, only those conductors that are intended for termination in a vertical section of a switchboard shall be located in that section.
Exception: Conductors shall be permitted to travel horizontally through vertical sections of switchboards where such conductors are isolated from busbars by a barrier.
(B) Overheating and Inductive Effects. The arrangement of busbars and conductors shall be such as to avoid overheating due to inductive effects.
(C) Used as Service Equipment. Each switchboard or panelboard, if used as service equipment, shall be provided with a main bonding jumper sized in accordance with 250.28(D) or the equivalent placed within the panelboard or one of the sections of the switchboard for connecting the grounded service conductor on its supply side to the
switchboard or panelboard frame. All sections of a switchboard shall be bonded together using an equipment bonding conductor sized in accordance with Table 250.122 or Table 250.66 as appropriate.
Exception: Switchboards and panelboards used as service equipment on high-impedance grounded-neutral systems in accordance with 250.36 shall not be required to be provided with a main bonding jumper.
(D) Terminals. In switchboards and panelboards, load terminals for field wiring, including grounded circuit conductor load terminals and connections to the equipment grounding conductor bus for load equipment grounding conductors, shall be so located that it is not necessary to reach across or beyond an uninsulated ungrounded line bus in order to make connections.
(E) Phase Arrangement. The phase arrangement on 3-phase buses shall be A, B, C from front to back, top to bottom, or left to right, as viewed from the front of the switchboard or panelboard. The B phase shall be that phase having the higher voltage to ground on 3-phase, 4-wire, delta-connected systems. Other busbar arrangements shall be permitted for additions to existing installations and shall be marked.
Exception: Equipment within the same single section or multisection switchboard or panelboard as the meter on 3-phase, 4-wire, delta-connected systems shall be permitted to have the same phase configuration as the metering equipment.
FPN: See 110.15 for requirements on marking the busbar or phase conductor having the higher voltage to ground where supplied from a 4-wire, delta-connected system.
(F) High-Leg Identification. A switchboard or panelboard containing a 4-wire, delta-connected system where the mid-point of one phase winding is grounded shall be legibly and permanently field marked as follows:
"Caution _____ Phase Has _____ Volts to Ground"
(G) Minimum Wire-Bending Space. The minimum wirebending space at terminals and minimum gutter space provided in panelboards and switchboards shall be as required in 312.6.


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## 360max (Jun 10, 2011)

molallaron said:


> 408.3a3 is referring to switchboards not branch circuit panelboards, or am I drinking my own bathwater


ARTICLE 408 Switchboards and Panelboards


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## Rick567 (Mar 3, 2011)

Damn, there's another code that I don't follow.


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## McClary’s Electrical (Feb 21, 2009)

To me, this yet again proves a load center is not a panel board. How many obey this rule in a residential setting?


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## cabletie (Feb 12, 2011)

molallaron said:


> My inspector is using 408.3a3 to require all conduits with even circuits to enter on right side and all with odd circuits to enter on left side . No crossing of hots ,neutrals or grounds. I do not see this section as requiring this.


I don't see it that way either.
as long as the conductors that leave the breakers in that section don't cross into another section you are fine.

I was surprised to see the exception. I have never used it. I just went back to each code book, all the way to 2005, to see when it started. it was there in 2005. Now I will have to dig out the actual book instead of the PDF version.

At one time I thought the exception was only for equipment and grounding electrode grounds. I could be wrong, it happens. Sometimes too often.


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## cabletie (Feb 12, 2011)

mcclary's electrical said:


> To me, this yet again proves a load center is not a panel board. How many obey this rule in a residential setting?



If you put switch gear in a residence then you would have to.


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## Shockdoc (Mar 4, 2010)

The pushmatic 40 ckt panel always had branch circuits sneaking over the bus bar to the inside ha Lloyd f.


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## 360max (Jun 10, 2011)

*Panelboard.* A single panel or group of panel units designed
for assembly in the form of a single panel, including
buses and automatic overcurrent devices, and equipped
with or without switches for the control of light, heat, or
power circuits; designed to be placed in a cabinet or cutout
box placed in or against a wall, partition, or other support;
and accessible only from the front

*
Switchgear.* An assembly completely enclosed on all sides
and top with sheet metal (except for ventilating openings
and inspection windows) and containing primary power circuit
switching, interrupting devices, or both, with buses and
connections. The assembly may include control and auxiliary
devices. Access to the interior of the enclosure is provided
by doors, removable covers, or both.
Informational Note: All switchgear subject to NEC requirements
is metal enclosed. Switchgear rated below 1000
V or less may be identified as “low-voltage power circuit
breaker switchgear.” Switchgear rated over 1000 V may be
identified as “metal-enclosed switchgear” or “metal-clad
switchgear.” Switchgear is available in non–arc-resistant or
arc-resistant constructions.


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## McClary’s Electrical (Feb 21, 2009)

cabletie said:


> If you put switch gear in a residence then you would have to.


(A) is for switchgear or panelboards. As you said in another thread, a panelboard is the sane as a load center, even though the manufactures distinguish a difference.


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## cabletie (Feb 12, 2011)

A load center is the same as a panelboard. Switchgear is different. I was kidding about having switchgear in a house. But if you ever had switchgear in a house, those rules would apply.


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## cabletie (Feb 12, 2011)

Normally these large breakers are numbered as 1. Not by individual phases like 1,3,5. NEMA has two different type panel schedules to reflect that.


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## cabletie (Feb 12, 2011)

408.3A says "as applicable".
A2 and A3 are specifically for switchboards, not panelboards.

The basic rule without the exception is they do not want feeders from one section traveling through another section. These sections are usually floor standing and 30" wide. one 30" wide section is considered a vertical section. It will only have a few breakers. 

I have never seen one fail because the 600 Kcmil feeder went from one side of the vertical section to other side of the vertical section. It was never a concern of the inspectors. They have always seen the switchgear with the covers off.

Most of the time the breakers are not numbered. They have engraved plaques riveted to the cover with the circuit description.


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## don_resqcapt19 (Jul 18, 2010)

There is only one "section" in a panelboard or a load center.


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