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DVOR 432
Installation
The network should be laid as symmetrical to the DVOR station as possible. The necessary length
and extension when laid in a straight line, should be estimated from the basic data below.
Strip length
25 m
50 m
100 m
2.6.3
Ground Rods
Ground rods are either pipes or U, L or T-shaped profiles driven vertically into the ground and 1 to
2 m in length. It is necessary to connect several ground rods together in order to reduce the grounding
resistance. The minimum spacing is twice the length of each ground rod.
Material: Steel (hot galvanized)
Probable grounding resistance of a rod:
The material, cross sectional areas and grounding resistance of the connecting leads to the shelter
should be as for strip ground conductors, (see Section 2.6.2). When pipe-type grounding rods are
fastened with clamps, screws at least M10 in size should be used.
2.6.4
Ground Plates
Ground plates are solid perforated sheet metal plates with dimensions of approx. 0.5 x 1 m or
1 x 1 m, which are embedded vertically in the ground. The top edge of the plates should always be
at least 1 m below the surface. Several ground plates must be connected in parallel in order to reduce
the grounding resistance. The minimum spacing should be 3 m. Material:
Sheet steel (hot galvanized)
Sheet copper
The ground resistance of a plate 1 m
cified in the tables in Section 2.6.2.
2.6.5
Estimating the Ground Resistance
The resistance of each rod, each plate and each supply line used should be determined on the basis
of Section 2.6.2 to 2.6.4. They should be considered as parallel resistances. The resulting grounding
resistance should then be calculated as follows: 1/R
count the nature of the terrain (for factors see Section 2.6.1) satisfactory grounding conditions can
be assumed if the ground resistance calculated from the base data is < 5
is 5
or more, we recommend measuring the ground resistance.
W
2-34
Ground resistance
10 W
5 W
3 W
Pipe
Bracket
U-profile
T-profile
Length 1 m approx. 70 W
Length 2 m approx. 40 W
min. thickness 3 mm
min. thickness 2 mm
@
is approx. 30 W. The data for the connecting conductors is spe
Operation and Maintenance
30 x 3 mm
L 65 x 65 x 7 mm
U 65 DIN 1026
T 60 DIN 1024
1
2
3
=1/R
+1/R
+1/R
+...+ R
res
W
Taking into ac
n.
. If the value calculated
Ed. 01.04
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