12.Locating Buried Sheath Faults And Earth Return Faults

(3MDynatelModels 2573 and 2573-iD only)

Note: Remove (disconnect) both the near-end and far-end grounding from the test section.

A. Transmitter Setup

Note: Do not make any connections while the transmitter is on. Fault location will not work unless the near-end and far-end grounds are disconnected.

Note: This method only works on direct buried cables/conductors. It will not work if the cables/conductors are faulted inside of a conduit, such as a PVC conduit.

Step 1. Attach the red clip to the earth-faulted conductor of the cable or conductor under test.

Step 2. Place the ground rod behind the transmitter and in parallel with the target path. Step 3. Connect the black clip to the ground rod behind the transmitter.

Step 4. Press and hold On/Off [1] to perform a battery test.

Step 5. Press on [T-2] once to power on the transmitter. This will place the transmitter in Ohm-meter mode. An Indicator Flag will be displayed above the ohm symbol, , in the Digital Display [T-4].

−− The resistance of the fault will be displayed in ohms on the transmitter Digital Display [T-4].

−− Resistance less than 50KΩ = Significant fault exists

−− Resistance 50KΩ to 1.0MΩ = High resistance fault exists (May or may not cause problems yet, but gets worse with time.)

−− Resistance greater than 1.0MΩ = No significant fault exists

Note: The fault locating limit is 2.0MΩ, although the transmitter's ohm-meter mode can display a fault resistance up to 10MΩ.

Step 6. Press on [T-2] again, to select Fault mode.

−− An Indicator Flag will be displayed above the fault locating symbol in the Digital Display [T-4]. (as shown in the illustration below)

Dynatel TM 2573 Trace

- + o

on

off

Flag

Output Level

Note: Two active line locating frequencies, 577 Hz and 33 kHz, are simultaneously transmitted with the fault finding signal. This allows convenient switching back and forth between fault finding mode and cable/pipe locate mode on the receiver during fault finding without returning to the transmitter. The transmitter display [T-4] will flash between 577 Hz and 33 kHz. It does not display the fault finding frequencies.

78-9000-0192-2 Rev C

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3M 2550, 2573 manual Locating Buried Sheath Faults And Earth Return Faults, Transmitter Setup