3M 2573, 2550 manual Pinpointing the Buried Fault

B. Pinpointing the Buried Fault

Step 1. Connect the 3M™ Earth Contact Frame to the External Jack [15] ([14] for 2550) of the receiver using the Earth Contact Frame cable (4 ft. (1.2 m) cable).

Step 2. Press On/Off [1] to power on the receiver. The receiver display screen will display "Fauly Calibrating" for about 5 seconds.

Step 3. Press Menu/OK [5].

Step 4. Press Fault [SK] to select Fault mode.

Step 5. Hold the receiver in one hand and the Earth Contact Frame in the other with the solid green-banded leg of the frame toward the test section. Near the location of the ground rod (about one Earth Contact Frame width away from the ground rod, slightly to the side and towards the faulted cable.), insert the Earth Contact Frame probes fully into the ground in line with the target path.

Step 6. Press REF [SK] to record the fault Signal Strength [9] ([8] for 2550 locator) level reference. The signal level will be recorded in the box above REF [SK] on the display. This reference indicates the Signal Strength [9] ([8]) for 2550 locator) level at the ground rod. When the operator reaches the major fault location, the Signal Strength [9] ([8]) for 2550 locator) indicated on the receiver will be very close (within 12dB) to this reference signal strength level.

Step 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 [8] (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 red-banded leg		Move in direction of green-banded leg
of 3M™ Earth Contact Frame.		of 3M™ Earth Contact Frame.
	Green Band	Red-and-White-Striped Band
Transmitter Signal		Ground Fault location

40 78-9000-0192-2 Rev C