Chapter 3 Wiring Methods and Materials

ARTICLE 310 -
CONDUCTORS FOR GENERAL WIRING
310.60
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Detail 1
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290 mm x 290 mm ~
(11.5 in. x 11.5 in.) 190 mm (7.5 in.)
Electrical duct bank
Detail 2
One electrical duct
475 mm x 475 mm
(19 in. x 19 in.)
190 mm (7.5 in.)
Electrical duct bank
Three electrical ducts Detail 3
or
475 mm x 675 mm
(19 in. x 27 in.)
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Electrical duct bank
. v • 'I Six electrical ducts
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190 mm 190 mm
(7.5 in.) (7.5 in.) .5
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675 mm x 290 mm
(27 in. x 11.5 in.)
Electrical duct bank
Three electrical ducts
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E
o
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190 mm 190 mm
(7.5 in.) (7.5 in.)
675 mm x 475 mm
(27 in. x 19 in.)
Electrical duct bank
Six electrical ducts
r
600mm
600mm
(24 in.) (24 in.) ~
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DetailS Detail 6 Detail7 Detail 8
Buried 3 Buried 3 Buried triplexed Buried triplexed
conductor conductor cables (1 circuit) cables (2 circuits)
cable
cables
190
rn
mm 190 mm 190 mm 190 mm 190 mm
(7.5 in.) (7.5 in.) (7.5 in.) (7.5 in.) 600mm
(7.5 in.)
(24 in.)
Detail 9
Detail 10
Buried single-conductor
Buried single-conductor
cables (1 circuit)
cables (2 circuits)
Legend
Note: Minimum burial depths to top electrical ducts or cables shall be
in accordance with 300.50. Maximum depth to the top of electrical
duct banks shall be 750 mm (30 in.) and maximum depth to the top
of direct buried cables shall be 900 mm (36 in,).
G:] Backfill (earth or concrete)
o Electrical duct
• Cable or cables
Figure 310.60 Cable Installation Dimensions for Use with Table 310.77 Through Table 310.86.
2008 Edition NATIONAL ELECTRICAL CODE 70-155