36
Protecting the measuring site
SWT4 User Manual v3.1
General recommendations for lightning protection and grounding for
stations with battery power
First step
Measure the distances between sensor
positions, data acquisition etc. to get to
know the potential levels
Recommendations for
lightning protection on
masts
2 or 3 meter masts can be equipped with a
lightning rod which is installed on top of the
mast, and a grounding rod which is
clamped to the foot of the mast. This
creates a zone of protection in a 45 degree
angle cone around the tip
Recommendations for
lightning protection of
enclosures
Install surge protection devices in one
corner of the measuring enclosure. All lines
to and from the surge protection devices
should not run parallel.
System protection of
stations with enclosure
and mast
Install a separate earth grid 50 cm below
the soil surface to equalize variations in the
ground potential between the sensors and
the mast grounding rod .
Lightning protection
with grounding rods
According to the standards the ground rod
(diam. 25 mm) must be inserted into the
ground for a minimum of 2,5 meters below
the frost level, i. e. in general 3 meters.
Cross shaped rods are less advisable for
such low depths, but this depends on soil
type, moisture or clay content, and distance
between soil surface and ground water
level.
