Calix 500 Series, Руководство пользователя

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Testing the Earth Electrode
The earth electrode is the bonding or connection point to the earth. The most common earth
electrodes are ground rods, metallic cold water pipes, underground grids and water wells that
use steel pipe. The ability of a grounding system to safely dissipate unwanted or harmful
potentials into the earth depends on the total resistance of the electrode, the resistance
between the conducting surface of the electrode, and the conducting surface of the soil that it
is in. The conductivity of the earth near and around the grounding system depends on the
chemical makeup and ambient moisture content of the soil.
The testing of an electrode measures the effectiveness of the earth electrode to provide
electrical contact with the earth. The lower the resistance to the earth is, the more effective
the ground system will be in dissipating energy safely.
To understand the testing procedure of an earth electrode, one must first understand some
of the principles of ground conductivity. The earth acts like it is made up of layers that bear a
resemblance to an onion. Like an onion, the earth is made up of expanding sections or peels
(layers). An electrode placed into the earth radiates current in all directions along the surface
of each of these layers, as depicted in the illustration below:
Ground Bond
#6 AWG
UL Listed
Clamp
Earth
Electrode
Earth
Layers
5229
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