User Manual

50
GPS Equipment User Manual - 4.0.0en
Main hazards of use, continued
- Additional protection against
lightning:
If there is a risk of a thunderstorm,
or if the equipment is to remain
unused and unattended for a long
period, protect your Leica
Geosystems GPS additionally by
unplugging all systems
components and disconnecting all
connecting cables and supply
cables (e.g. Receiver - Antenna).
Suggestion for design of a
Lightning Conductor for a GPS
System
1. On non-metallic structures
Protection by Air Terminals is
recommended. An Air Terminal is a
pointed solid or tubular rod of
conducting material with proper
mounting and connection to a
conductor. The position of 4 Air
Terminals should be uniformly
distributed around the Antenna at a
distance equal to the height of the Air
Terminal.
The Air Terminal diameter should be
12mm for copper or 15mm for
aluminium. The height of the Air
Terminals should be 25 to 50cm. All
Air Terminals should be connected to
the down conductors. The diameter
of the Air Terminal should be kept to
a minimum to reduce GPS signal
shading.
2. On metallic structures
Protection is as described for non-
metallic structures, but the Air Termi-
nals can be connected directly to the
conducting structure without the need
for down conductors.
- If a Leica Geosystems GPS has to
be permanently mounted in an
exposed location, it is advisable to
provide a lightning conductor
system. A suggestion on how to
design a lightning conductor for a
Leica Geosystems GPS is given
below. Always follow the
regulations in force in your country
with regard to grounding Antennas
and masts. These installations
must be carried out by an
authorised specialist.
- To prevent damages due to
indirect lightning strikes (voltage
spikes) cables (antenna, power
source, modem, ...) should be
protected with appropriate
protection elements (lightning
arrestor). These installations must
be carried out by an authorized,
local specialist.
Safety Directions