User's Manual

Access P oint Hardw are Installation Earth Ground and P ower Cables
Earth Ground and Power Cables
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The objective of this procedure is to install the power and earth ground cabling for the Base
Control Unit (B CU) and RF Head.
The site should have had an external ground ring or bus bar being used. The ground ring and
bus bar should be an integral part of the structures that will hold the equipment. Reference
Hard copy (Motorola P art Number 6881089E50) .
Grounding Considerations
Above Ground F or ground rings and the interconnection of internal and external ground
rings, #2 to #6 A WG may be used. F or grounding of equipment and miscellaneous metallic
objects, #6 A WG minimum is required.
Exceptions Connection from an isolated ground bar (IGB) to master ground bar (MGB) is
accomplished using #2 to #6 A WG . The external ground bar (EGB) is grounded through a 2 -inch
(50.8 mm) wide, 16 -gauge copper strap, if available; otherwise, 2 -#6 A WG wires can be used. If
the #6 A WG wires are used, then they must be connected at opposite ends of the EGB and have
a minimum separation of 12 -inches between them.
Below Ground All wire must be #2 A WG as a minimum. Ground rods are to be a minimum of
8 feet long and 5/8 -inch in diameter . In the case of a deep basement next to the rod, the rod
must be long enough to extend 3 feet below the basement floor .
BCU Grounding
The B CU should be tied to a single point grounded to the system master ground (ground bus
bar). All interconnect cables should be in metallic sealtight type conduit or solid shield RF
cables. It is recommended that these cables be run in raceways to reduce the loop dimensions
of the cable runs. This minimizes the effect of inducted currents caused by the intense
electromagnetic field of lightning current. A ground stud is provided on the external surface of
the B CU enclosure to attach the ground wire. Refer to requirements for cable A in T able 3 -1 .
RF Head Grounding
All RF cables should be in metallic sealtight type conduit or solid shield RF cables. It is
recommended that these cables be run in raceways to reduce the loop dimensions of the cable
runs. This minimizes the effect of inducted currents caused by the intense electromagnetic field
of lightning current. A ground lug with captive screws is provided on the RF Head to attach
the ground wire.
68P09277A59 -8 3 -5
PRELIMINARY - UNDER DEVELOPMENT MA Y 2007