260-668066-003 Rev 001 August 2010 5-3
Eclipse Installation Manual
Safety Requirements for Equipment Grounding
1. Ground wires must provide a direct, low impedance path to the Master Ground bar
for the building, which should be located adjacent to the point of waveguide entry
to the building.
2. Do not connect other equipment to the same grounding cable as the IRU 600. Each
item of equipment in a rack must be separately grounded to the rack ground bar.
The rack ground bar is then grounded directly to the building Master Ground.
3. The IRU 600 and INU must be located in the same immediate area (same or
adjacent racks/cabinets) as with any other equipment that is connected to the same
DC supply circuit point of grounding. DO NOT ground the INU and IRU 600
elsewhere.
4. All intra-building signal cabling must be shielded and both ends of each shield
must be grounded.
5. There shall 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 waveguide grounds
required is 3:
• One located at the top of the vertical waveguide run, about 1 meter below the bend
before the waveguide goes horizontal toward the antenna,
• 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,
• 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
For NEBS compliance:
• The equipment is to be grounded to a Common Bonding Network.
• All bare conductors must be coated with an appropriate antioxidant compound
before crimp connectors are fitted.
• All unplated connectors, braided strap, and bus bars must be brought to a bright
finish and then coated with an antioxidant before they are connected. This does not
apply to tinned, solder-plated, or silver-plated connectors and other plated
connection surfaces – but all must be clean and free of contaminants.
• All raceway fittings must be tightened to provide a permanent low-impedance path.
To Next Page
Loading...
General