Page 774 - 2018_IRC

POWER AND LIGHTING DISTRIBUTION

E3907.2 Damp and wet locations. In damp or wet locations, 3. A fitting is provided on each end of the raceway to
cabinets and panelboards of the surface type shall be placed protect the cable(s) from abrasion and the fittings
or equipped so as to prevent moisture or water from entering remain accessible after installation.
and accumulating within the cabinet, and shall be mounted to 4. The raceway is sealed or plugged at the outer end
1
provide an air-space not less than / inch (6.4 mm) between using approved means so as to prevent access to the
4
the enclosure and the wall or other supporting surface. Cabi- enclosure through the raceway.
nets installed in wet locations shall be weatherproof. For 5. The cable sheath is continuous through the raceway
enclosures in wet locations, raceways and cables entering and extends into the enclosure beyond the fitting not
above the level of uninsulated live parts shall be installed less than / inch (6.4 mm).
1
with fittings listed for wet locations. (312.2) 4
6. The raceway is fastened at its outer end and at other
Exception: Nonmetallic enclosures installed on concrete, points in accordance with Section E3802.1.
masonry, tile, or similar surfaces shall not be required to
be installed with an air space between the enclosure and 7. The allowable cable fill for conduit or tubing shall
the wall or supporting surface. (312.2 Exception) not exceed that permitted by Table E3907.8 and shall
be considered as a complete conduit or tubing sys-
E3907.3 Position in wall. In walls of concrete, tile or other tem. A multiconductor cable having two or more con-
noncombustible material, cabinets and panelboards shall be ductors shall be treated as a single conductor for
installed so that the front edge of the cabinet will not set back calculating the percentage of conduit fill area. For
of the finished surface more than / inch (6.4 mm). In walls cables that have elliptical cross sections, the cross-
1
4
constructed of wood or other combustible material, cabinets sectional area calculation shall be based on the major
shall be flush with the finished surface or shall project there- diameter of the ellipse as a circle diameter. [312.5(C)
from. (312.3) Exception]
E3907.4 Repairing noncombustible surfaces. Noncombus- TABLE E3907.8 (Chapter 9, Table 1)
tible surfaces that are broken or incomplete shall be repaired PERCENT OF CROSS SECTION OF
1
so that there will not be gaps or open spaces greater than / 8 CONDUIT AND TUBING FOR CONDUCTORS
inch (3.2 mm) at the edge of the cabinet or cutout box NUMBER OF MAXIMUM PERCENT OF CONDUIT AND
employing a flush-type cover. (312.4) CONDUCTORS TUBING AREA FILLED BY CONDUCTORS
1 5 3
E3907.5 Unused openings. Unused openings, other than those
intended for the operation of equipment, those intended for 2 3 1
mounting purposes, and those permitted as part of the design Over 2 40
for listed equipment, shall be closed to afford protection sub-
stantially equivalent to that of the wall of the equipment. Metal E3907.9 Wire-bending space within an enclosure contain-
plugs and plates used with nonmetallic cabinets shall be ing a panelboard. Wire-bending space within an enclosure
1
recessed at least / inch (6.4 mm) from the outer surface. containing a panelboard shall comply with the requirements
4
Unused openings for circuit breakers and switches shall be of Sections E3907.9.1 through E3907.9.3.
closed using identified closures, or other approved means that E3907.9.1 Top and bottom wire-bending space. The top
provide protection substantially equivalent to the wall of the and bottom wire-bending space for a panelboard enclosure
enclosure. (110.12(A)] shall be sized in accordance with Table E3907.9.1(1)
E3907.6 Conductors entering cabinets. Conductors enter- based on the largest conductor entering or leaving the
ing cabinets and panelboards shall be protected from abrasion enclosure. [408.55 (A)]
and shall comply with Section E3906.1.1. (312.5) Exceptions:
E3907.7 Openings to be closed. Openings through which 1. For a panelboard rated at 225 amperes or less and
conductors enter cabinets, panelboards and meter sockets designed to contain not more than 42 overcurrent
shall be closed in an approved manner. [312.5(A)] devices, either the top or bottom wire-bending
E3907.8 Cables. Where cables are used, each cable shall be space shall be permitted to be sized in accordance
secured to the cabinet, panelboard, cutout box, or meter with Table E3907.9.1(2). For the purposes of this
socket enclosure. [312.5(C)] exception, a 2-pole or a 3-pole circuit breaker shall
Exception: Cables with entirely nonmetallic sheaths shall be considered as two or three overcurrent devices,
be permitted to enter the top of a surface-mounted enclo- respectively. [408.55(A) Exception No. 1]
sure through one or more sections of rigid raceway not less 2. For any panelboard, either the top or bottom
than 18 inches (457 mm) nor more than 10 feet (3048 mm) wire-bending space shall be permitted to be sized
in length, provided all the following conditions are met: in accordance with Table E3907.9.1(2) where the
1. Each cable is fastened within 12 inches (305 mm), wire-bending space on at least one side is sized in
measured along the sheath, of the outer end of the accordance with Table E3907.9.1(1) based on the
raceway. largest conductor to be terminated in any side
2. The raceway extends directly above the enclosure wire-bending space. [408.55(A) Exception No. 2]
and does not penetrate a structural ceiling.

2018 INTERNATIONAL RESIDENTIAL CODE ® 749
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