097-72020-01 Revision K – December 2005 TimeSource 3100 User’s Guide 33
Chapter 2 Engineering & Ordering
Lightning Suppressor Guidelines
Lightning Suppressor Guidelines
Mount the lightning suppressor within 4.6 meters of a valid, direct, low impedance,
low resistance, earth ground connection point. Valid earth grounds include the roof
ring ground system, building structural steel, or a Central Office ground plate. If the
grounding point is inside the building, mount the suppressor within 15 meters of the
cable entry into the building.
Route the ground wire as straight as possible (bends in the ground wire increase
impedance at lightning frequencies), in accordance with local company practices.
Treat all exposed connections with an electrically conductive anti-corrosion
compound (Kopr-Shield or equivalent).
Antenna Location Guidelines
The ideal antenna location provides a clear, unobstructed view of the sky from the
zenith to the horizon line, and 360 degrees around the horizon.
A compromise often must be made between location and satellite field of view. The
smaller the field of view, the fewer satellites that can be used in the timing solution
for GPS derived time.
Signals closer to the horizon are often subject to multipath effects, which degrade
the timing solution. The TimeSource 3100 can be set to ignore, or mask, all signals
from the horizon to a chosen angle of elevation (mask angle), as shown in Figure
2-1
Warning: To prevent possible lightning-induced damage, do not use
metal clamps that form a complete circle around the antenna cable or
the cable conduit. This type of ring clamp acts as a choke coil to
induce currents which resist current flow and hampers proper
lightning protection.
Warning: To prevent possible lightning-induced damage, install the
lightning suppressor away from electrical devices or cabling that may
induce arcing.
Note: To keep the grounding scheme intact, keep all impedances as
low as possible. Avoid small-radius turns and unnecessary turns.
To Next Page
Loading...
Need help?
General
