Panel box as a passageway

[Joe Funderburk, CMI]

Anyone know the code number in the NEC that prohibits a panel from being used as a passageway for wiring?

[Jeffrey R. Pope]

It's less of a "code" issue, and more of a listing issue.

110.3 Examination, Identification, Installation, and Use of Equipment.

(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

Panel boards are not "listed" to be used as raceways.

[Joe Funderburk, CMI]

Thanks Jeff.

[Joe Funderburk, CMI]

Jeff, what if those wires 'passing through' were cut and spliced together? Wouldn't that be allowed because a panel can be used as a junction box?

[Robert Meier]

You can use a panelboard for splices or for pulling through. The 2011 added a requirement that the panelboard be marked when using for a pull through.


2011 NEC:

312.8 Switch and Overcurrent Device
Enclosures with Splices, Taps, and Feed-
Through Conductors
The wiring space of enclosures for switches or overcurrent
devices shall be permitted for conductors feeding through,
spliced, or tapping off to other enclosures, switches, or overcurrent
devices where all of the following conditions are
met:
(1) The total of all conductors installed at any cross section
of the wiring space does not exceed 40 percent of the
cross-sectional area of that space.
(2) The total area of all conductors, splices, and taps installed
at any cross section of the wiring space does not
exceed 75 percent of the cross-sectional area of that
space.
(3) A warning label is applied to the enclosure that identifies
the closest disconnecting means for any feedthrough
conductors.

2008 NEC:

312.8 Enclosures for Switches or Overcurrent Devices.
Enclosures for switches or overcurrent devices shall not be used as junction boxes, auxiliary gutters, or raceways for conductors feeding through or tapping off to other switches or overcurrent devices, unless adequate space for this purpose is provided. The conductors shall not fill the wiring space at any cross section to more than 40 percent of the cross-sectional area of the space, and the conductors, splices, and taps shall not fill the wiring space at any cross section to more than 75 percent of the cross-sectional area of that space.

[Jeffrey R. Pope]

Originally Posted by jfunderburk

Jeff, what if those wires 'passing through' were cut and spliced together? Wouldn't that be allowed because a panel can be used as a junction box?

As Robert provided, the panel can be used for both purposes as long as there is adequate space. The only prohibiting factor would be with regards to the panel listing.