Temper KOBAN K KMPC-01-50A Manual página 39

7.2.1. Inclined angle method
In general, the measurement of grounding impedance of large grounding devices adopts the mode
of the included Angle arrangement of the current and voltage line. Generally, the distance between
current pile C and the tested grounding device edge d
of the grounding network. The length of d
can be modified by the following formula:
The formula: θ-- the inclined angle of the current line and voltage line;
Z'--the tested value of the grounding impedance.
If soil resistivity is uniform, can use the isosceles triangle wiring with d
other. At this time, the inclined angle θ is about 30°, and the modified calculation formula of
d =d =2D ground impedance is still same as above formula
PG CG
Test mode selection: G.Grid VF 1A
7.2.2. Straight-line method
The current pile and voltage pile are in straight line with the measured grounding device . Generally,
the distance between current pile C and the tested grounding device edge d
of the diagonal length of the grounding grid. The distance d
of the tested grounding device is usually (0.5~0.6) d
current line and the voltage line should be kept as far as possible to reduce the influence of
electromagnetic coupling on the test results.
The resistance of the current pile should be reduced as much as possible, and water can be used
to reduce the resistance if necessary. The instrument use the "CPILE" or "VPILE" mode to
measuring, the current pile resistance should be less than 80Ω, voltage pile should be less than
should be 4~6 times of the diagonal length
CG
is 0.618 times to d
PG
CG
between voltage pile P and the edge
PG
. When wiring, the distance between the
CG
10
. The grounding impedance formula
and d equal to each
PG CG
should be 4~5 times
CG