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Ends of cable shall be taped immediately after cutting to prevent moisture
from entering the cable. Where the cable is not expected to be connected
for at least 72 hours, the tape shall also be varnished.
3.1.4
Underground Conduit/Duct Without Concrete Encasement
Type of conduit shall be [EPC-40-PVC,] [EPC-80-PVC,] [PVC-coated rigid
galvanized steel,] [PVC-coated intermediate galvanized steel,] [rigid
galvanized steel,] [intermediate galvanized,] [or] [rigid galvanized steel
field wrapped with 0.254 mm 0.010 inch thick pressure-sensitive plastic
tape applied with a 50 percent overlap].
3.1.4.1
Conduit Installation
Top of the conduit shall be not less than 610 mm 24 inches below grade, and
shall have a minimum slope of 75 mm 3 inches in each 30 meters 100 feet
away from buildings and toward manholes and other necessary drainage
points. Run conduit in straight lines except where a change of direction
is necessary. As each conduit run is completed, for conduit sizes 75 mm 3
inches and larger, draw a flexible testing mandrel approximately 305 mm 12
inches long with a diameter less than the inside diameter of the conduit
through the conduit. After which, draw a stiff bristle brush through until
conduit is clear of particles of earth, sand and gravel; then immediately
install conduit plugs. For conduit sizes less than 75 mm 3 inches, draw a
stiff bristle brush through until conduit is clear of particles of earth,
sand and gravel; then immediately install conduit plugs. Provide not less
than 75 mm 3 inches clearance from the conduit to each side of the trench.
A minimum clearance of 65 mm 2 1/2 inches shall be provided between
adjacent conduits. Grade bottom of trench smooth; where rock, soft spots,
or sharp-edged materials are encountered, excavate the bottom for an
additional 75 mm 3 inches, fill and tamp level with original bottom with
sand or earth free from particles, that would be retained on a 6.25 mm 1/4
inch sieve. Provide color, type and depth of warning tape as specified in
Section 02300 EARTHWORK.
3.1.4.2
Encasement Under Roads and Structures
Under roads, paved areas, and railroad tracks, install conduits in concrete
encasement of rectangular cross-section providing a minimum of 75 mm 3 inch
concrete cover around ducts. Concrete encasement shall extend at least
1525 mm 5 feet beyond the edges of paved areas and roads, and 3660 mm 12
feet beyond the rails on each side of railroad tracks. Conduits to be
installed under existing paved areas which are not to be disturbed, and
under roads and railroad tracks, shall be zinc-coated, rigid steel, jacked
into place. [Hydraulic jet method shall not be used.]
3.1.4.3
Multiple Conduits
Separate multiple conduits by a minimum distance of 65 mm 2 1/2 inches,
except that light and power conduits shall be separated from control,
signal, and telephone conduits by a minimum distance of 75 mm 3 inches.
Stagger the joints of the conduits by rows and layers to strengthen the
conduit assembly. Provide plastic duct spacers that interlock vertically
and horizontally. Spacer assembly shall consist of base spacers,
intermediate spacers, and top spacers to provide a completely enclosed and
locked-in conduit assembly. Install spacers per manufacturer's
instructions, but provide a minimum of two spacer assemblies per 3050 mm 10
SECTION 16302N
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