User's Manual

ECLIPSE INSTALLATION MANUAL
Safety Requirements for Equipment Grounding
l Do not assume that an existing rack or mounting frame is correctly grounded.
Always check the integrity of the ground connections, which must include a
check through to the master ground for the station, which should be located at
the point of cable entry to the equipment building. Ground wires must provide
a direct, low impedance path to the master ground bar.
l Do not connect other equipment to the same grounding cable as the INU. Each
item of equipment in a rack must be separately grounded to the rack ground
bar.
l The INU / IRU 600 must be located in the same immediate area (adjacent
racks/cabinets) as all other equipment with a (ground) connection to a
common DC supply source.
l All intra-building signal cabling must be shielded and both ends of each shield
must be grounded.
l There must be no switching or disconnecting devices in the grounded circuit
conductor between the DC source and the point of connection of the grounding
electrode conductor.
Waveguide Grounding
Grounding the waveguide is an essential part of the overall lightning protection
scheme at the site. The number of waveguide grounds required is dependant on the
antenna height at its centerline. At a height of 45m, the minimum number of wave-
guide grounds required is three:
l One located at the top of the vertical waveguide run, about 1 meter below the
bend before the waveguide goes horizontal toward the antenna,
l One located at the bottom of the vertical cable run, about a meter above the
bend before the waveguide goes horizontal toward the equipment room entry
point,
l One located at the equipment room entry way point.
The top and bottom ground is typically connected to a tower ground bar, or to the
tower steel using a ground clamp. The entryway ground should be attached to the
ground bus bar, generally located directly below the waveguide entryway point.
If the height of the antenna centerline is greater than 45m, then additional grounds
are required every 25m, or part of, above the 45m level. The topmost one should be
located about 1 meter below the bend before the waveguide goes horizontal toward
the antenna.
NEBS Compliance
l Use a 16 mm2 (AWG 6) green PVC insulated stranded copper ground wire
(not 4 mm
2
) together with a star washer under the grounding screw at the
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