312.8 Changes

[Jim Port]

Notice the difference between the wording. This is the 05.


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.

Here is the 2011 Draft.

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. [ROP 9-34]

Hopefully this clears things up.

[ken horak]

And the actual wording from the 2011 NEC is the same as the ROP that Jim posted:

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.

[Jim Port]

Thanks for the confirmation Ken. Looks like all that stuff about needing the space identified somehow has been clarified and was not the intent of the CMPs.

[ken horak]

Thanks for the confirmation Ken. Looks like all that stuff about needing the space identified somehow has been clarified and was not the intent of the CMPs.

yes sir - you are correct