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78-8130-6151-8 Rev G
3. Press
Locate
[5].
4. Press
Fault
[SK] to select Fault mode.
5. Hold the receiver in one hand and the 3M™ Earth Contact Frame in the other with
the solid green-banded leg of the Earth Contact Frame toward the test section. Near
the location of the ground rod (about one Earth Contact Frame width away), insert
the Earth Contact Frame probes fully into the ground in line with the target path.
6. Press
Ref
[SK] to record the fault level reference signal. The signal level will be
recorded in the box above
Ref
[SK] on the display. This reference indicates the
Signal Strength
[10] level at the ground rod. When the operator reaches the major
fault location, the
Signal Strength
[10] indicated on the receiver will be very close
(within 12dB) to this reference signal level.
7.
Continue along the cable path, re-inserting the Earth Contact Frame probes every
few steps while watching the receiver bar graph. The bar graph on the receiver will
fill toward the right side of the display (green
Fault Finding Direction Indicator
[13] (See illustration below.)), indicating that the fault is ahead of the operator (in
the direction of the green-banded leg of the Earth Contact Frame).
Move in direction of green-banded leg of
3M™ Earth Contact Frame.
Move in direction of red-banded leg of
3M™ Earth Contact Frame.
Transmitter Signal
Ground Fault location
8. When the bar graph fills toward the left (red-and-white-striped
Fault Finding
Direction Indicator
[13] (See illustration above.)) side of the display, the fault has
been passed and is now behind the operator. Move back, inserting the Earth Contact
Frame every few inches, until the arrows alternate back to green. Mark the point
beneath the center of the Earth Contact Frame. Turn the Earth Contact Frame 90
degrees and insert into the ground over the previously marked point. Move the
Earth Contact Frame to the left and right (following the directions of the green and
red indicator arrows). When the arrows reverse a third time, turn the Earth Contact
Frame 90 degrees again. Pinpoint the fault by moving the Earth Contact Frame in
the direction of the green and red arrows. The fault is located beneath the center of
the Earth Contact Frame when the arrows change from one side to the other this
time.
