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Is this a no no?


DonTx
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Jim,

Here's 408.3 from the 2002 NEC. It looks to be on point as I read it, particularly the exception. I don't see any "isolation by a barrier" in that photo. Nice find Danny.

408.3 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), (2), and (3) as applicable.

(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.

Brian G.

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Originally posted by Brian G.

Jim,

Here's 408.3 from the 2002 NEC. It looks to be on point as I read it, particularly the exception. I don't see any "isolation by a barrier" in that photo. Nice find Danny.

. . .

Brian G.

Whoa there! That used to be section 384-3. Read section (3) and the exception again. They're talking about *switchboards* not panelboards. We're unlikely to find a switchboard in a residence.

For those who're interested, switchboards are part of the power distribution system in large commercial buildings. They're big things, about as tall as O'Handley and much wider. They typically have two or more sets of vertical sections, each dedicated to a specific purpose. For instance one section might contain the incoming power from a transformer while another might have metering devices and a third would contain distribution equipment. Each section's about as big as a closet.

I believe that section (3) is referring to those "sections." Not the vertical spaces on either side of the buses in a panelboard.

As for Donald's original question, I'm not aware of anything that would prohibit the white wires in that picture from crossing the buses. My guess is that, if there is a prohibition, you'll find in the UL listing.

- Jim Katen, Oregon

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Jim,

When I originally read that code I thought the same thing as you.Large switchboards not panels.Then I looked up the NEC definition of panelboards and switchboards.

PANELBOARDS: 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.

SWITCHBOARD: A large single panel, frame, or assembly of panels on which are mounted on the face, back, or both, switches, overcurrent and other protective devices, buses, and usually instruments. Switchboards are generally accessible from the rear as well as from the front and are not intended to be installed in cabinets.

Correct me if I am wrong but if I read this correctly a switchboard can be mutiple panels assembled together.Then I would think that 408.3(A)(3)does apply.

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Originally posted by Danny Pritchard

Jim,

When I originally read that code I thought the same thing as you.Large switchboards not panels.Then I looked up the NEC definition of panelboards and switchboards.

PANELBOARDS: 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.

SWITCHBOARD: A large single panel, frame, or assembly of panels on which are mounted on the face, back, or both, switches, overcurrent and other protective devices, buses, and usually instruments. Switchboards are generally accessible from the rear as well as from the front and are not intended to be installed in cabinets.

Correct me if I am wrong but if I read this correctly a switchboard can be mutiple panels assembled together.Then I would think that 408.3(A)(3)does apply.

Danny,

I'll ask around and find out whether or not multiple panels assembled together constitute a switchboard. (Though I doubt it.)

In any case, it wouldn't apply in Donald's photo anyway. That's clearly a plain vanilla, dime-a-dozen panelboard.

- Jim Katen, Oregon

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