Pinpointing Sheath Faults in „ESG“ Mode
84
6.2.2
Procedure
In the following picture you can see several points of an ideal signal route from the
feeding point to the fault position and beyond:
As voltage gradients induced by the current flowing back from the fault position exist
around the earthing point of the generator, the measurement values near this point
might be elevated (position
). However, the deflection direction (polarity) also
indicates the direction of the fault position at this point.
At half-way point between the generator and the fault position, the signal strength
reaches a minimum (position
). On moving nearer to the fault (position
), the
signal strength increases again. The maximum signal strength is measured when one of
the earth spikes is directly above the fault.
If the fault is exactly between the two earth spikes or exactly to the side (position
),
the indicator unit does not display a reading.
If the fault position is passed by, the polarity changes (position
). The signal on the
indicator unit points to the other direction.
Diagram
Summary of Contents for digiPHONE+2
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