Page 773 - 2018_IRC

POWER AND LIGHTING DISTRIBUTION

pholder or other equipment and is supported by entering being suitably protected from corrosion and shall be
3
raceways shall not exceed 100 cubic inches (1640 cm ) in securely embedded in concrete or masonry. [314.23(G)]
size. The enclosure shall have threaded entries or identi- E3906.9 Covers and canopies. In completed installations,
fied hubs. The enclosure shall be supported by two or each box shall have a cover, faceplate, lampholder or lumi-
more conduits threaded wrench-tight into the enclosure or naire canopy. Screws used for the purpose of attaching covers,
hubs. Each conduit shall be secured within 18 inches (457 or other equipment to the box shall be either machine screws
mm) of the enclosure. [314.23(F)] matching the thread gauge or size that is integral to the box or
Exceptions: shall be in accordance with the manufacturer’s instructions.
(314.25)
1. Rigid metal or intermediate metal conduit shall be
permitted to support a conduit body of any size, E3906.10 Covers and plates. Covers and plates shall be non-
provided that the conduit bodies are not larger in metallic or metal. Metal covers and plates shall be grounded.
trade size than the largest trade size of the support- [314.25(A)]
ing conduit. [314.23(F) Exception No. 1] E3906.11 Exposed combustible finish. Combustible wall or
2. An unbroken length(s) of rigid or intermediate ceiling finish exposed between the edge of a fixture canopy
metal conduit shall be permitted to support a box or pan and the outlet box shall be covered with noncombusti-
used for luminaire or lampholder support, or to ble material where required by Section E4004.2. [314.25(B)]
support a wiring enclosure that is an integral part E3906.12 Separable attachment fittings. Where outlet
of a luminaire and used in lieu of a box in accor- boxes required in Section E3905.6 support listed locking sup-
dance with Section E3905.1.1, where all of the port and mounting receptacles used in combination with com-
following conditions are met: patible attachment fittings, the combination shall be
2.1. The conduit is securely fastened at a identified for the support of equipment within the weight and
point so that the length of conduit mounting orientation limits of the listing. Where the support-
beyond the last point of conduit support ing receptacle is installed within a box, it shall be included in
does not exceed 3 feet (914 mm). the fill calculation given in Section E3905.12.2.4.
2.2. The unbroken conduit length before the
last point of conduit support is 12 inches SECTION E3907
(305 mm) or greater, and that portion of CABINETS AND PANELBOARDS
the conduit is securely fastened at some
point not less than 12 inches (305 mm) E3907.1 Space within switch and overcurrent device
from its last point of support. enclosures. Where the wiring space of enclosures for
switches or overcurrent devices contains conductors that are
2.3. Where accessible to unqualified persons, feeding through, spliced, or tapping off to other enclosures,
the luminaire or lampholder, measured to switches, or overcurrent devices, all of the following condi-
its lowest point, is not less than 8 feet tions shall apply:
(2438 mm) above grade or standing area
and at least 3 feet (914 mm) measured 1. The total area of all conductors installed at any cross
horizontally to the 8-foot (2438 mm) ele- section of the wiring space shall not exceed 40 percent
vation from windows, doors, porches, of the cross-sectional area of that space.
fire escapes, or similar locations. 2. The total area of all conductors, splices, and taps installed
at any cross section of the wiring space shall not exceed
2.4. A luminaire supported by a single conduit
does not exceed 12 inches (305 mm) in 75 percent of the cross-sectional area of that space.
any direction from the point of conduit 3. A warning label shall be applied to the enclosure that
entry. identifies the closest disconnecting means for any feed-
through conductors. (312.8)
2.5. The weight supported by any single con-
duit does not exceed 20 pounds (9.1 kg). E3907.1.1 Power monitoring equipment. Where the wir-
ing space of enclosures for switches or overcurrent devices
2.6. At the luminaire or lampholder end, the contains power monitoring equipment, all of the following
conduit(s) is threaded wrenchtight into conditions shall be met:
the box, conduit body, or integral wiring
enclosure, or into hubs identified for the 1. The power monitoring equipment shall be identified
purpose. Where a box or conduit body is as a field installable accessory as part of the listed
used for support, the luminaire shall be equipment, or shall be a listed kit evaluated for field
secured directly to the box or conduit installation in switch or overcurrent device enclo-
body, or through a threaded conduit nip- sures.
ple not over 3 inches (76 mm) long. 2. The total area of all conductors, splices, taps and
[314.23(F) Exception No. 2] equipment at any cross section of the wiring space
E3906.8.6 Enclosures in concrete or masonry. An shall not exceed 75 percent of the cross-sectional
enclosure supported by embedment shall be identified as area of that space.

748 2018 INTERNATIONAL RESIDENTIAL CODE ®
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