Buried Sheath Faults And Earth-Return Faults; Transmitter Setup; Pinpointing The Buried Fault - 3M Dynatel 2250M Series Operator's Manual

BURIED SHEATH FAULTS AND EARTH/RETURN FAULTS
*** Remove both the near-end and far-end grounding from the test section.

Transmitter Setup

Note: Do not make any connections while the transmitter is on.
Attach the red clip to the earth-faulted conductor of the cable or conductor
under test.
Place the ground rod behind the transmitter and in parallel with the target
path.
Connect the black clip to the ground rod behind the transmitter and in
parallel with the target path.
Press and hold OFF [T-1] to perform a battery test.
Press OHMS/FAULT/TONE [T-2] to turn the transmitter on.
The resistance of the fault will be displayed in ohms on the transmitter
display [T-4].
Press OHMS/FAULT/TONE [T-2] again, to select Fault mode.
The flag will turn on under the fault icon.

Pinpointing the Buried Fault

Connect the 3M
JACK [13] of the receiver using the earth frame cable.
Press POWER [1] to turn the Receiver on.
Press Locate [5].
Press Fault [SK] to select Fault mode.
Hold the receiver in one hand and the frame in the other with the green-
banded leg of the frame toward the test section.
Near the location of the ground rod (about one frame width away), insert the
frame probes fully into the ground in line with the target path.
Press REF [SK] to record the fault level reference. 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 level.
Dynatel Earth Contact Frame to the EXTERNAL
™ ™
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