Motorola SC 4812ET RF, Hardware Installation Manual, Page: 52 / 192

Site Preparation
– continued
DRAFT
SC TM 4812ET RF and Power Cabinet Hardware Installation Manual
Apr 2001
52
Installation Procedure:
Install the concrete pad and ground system as described in Table 2-9.
Table 2-9: Concrete Pad and Ground System Installation Procedure
Step Action
1 Ensure that the pad location is firm and level. If the ground around the location is not firm, compact
the soil and construct a level base for the pad using a minimum of six inches of gravel or per local
code requirements.
2 Dig trenches 610 mm (24”) deep (minimum), and wide enough to accommodate the ground ring and
conduits.
3 Install conduits. Recommended locations are shown in Figure 2-6. Refer to Table 2-6, and Table 2-7
for minimum bend radius of Foam Heliax and maximum number of Heliax in a conduit.
4 Install 152 mm (6”) concrete pad frame with integral rebars and dry wells. Refer to Figure 2-6 for pad
dimensions.
5 Install #3 BSWG (#2 AWG; 35 mm
2
) solid tinned copper perimeter ground ring (see Figure 2-3).
6 Exothermic weld #3 BSWG (#2 AWG; 35 mm
2
) solid tinned copper wire from concrete pad rebar to
perimeter ground ring.
7 Install copper clad steel ground rods.
8 Exothermic weld perimeter ground ring to steel ground rods.
9 Install three #3 BSWG (#2 AWG; 35 mm
2
) solid tinned copper wires, exothermic welded to perimeter
ground ring, for BTS master ground, Power Cabinet master ground, and for antenna tower ground
straps.
NOTE
For sites with multiple cabinets an additional #3 BSWG (#2 AWG; 35 mm
2
) solid tinned copper wire
must be installed for each additional cabinet.
10 Fill the trenches in the area of the pad with soil and tamp.
11 Pour concrete until level or slightly above the concrete forms. Puddle the concrete along the edges of
the forms. Use a straight piece of lumber or equivalent as a guide to level the concrete.
12 For additional finishing, wait until the pad no longer looks as if water is standing on top and trowel
smooth.
13 After the second day the concrete forms can be removed.
14 The concrete mounting pad must cure adequately before the cabinets may be installed.
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