Finding Shorts; Tracing Wires In Metal Conduit - Amprobe AT-6020 User Manual

4. SPECIAL APPLICATIONS
The tracing signal generated by the Transmitter is conducted along the wire as long as there is
continuity in the metal conductor. To find a fault, trace the wire until the signal stops. To verify
the fault's location, move the Transmitter to the other end of the wire and repeat, tracing from
the opposite end. If signal stops at the exact same location, the fault has been located.
Note: If the place of the fault is not found, the result may be a high resistance break
(partially open circuit). Such a break would stop higher currents from flowing but will
conduct the tracing signal through the break. Such faults will not be detected until the wire
is completely open.

4.3 Finding Shorts

Shorted wires will cause a breaker to trip. To correct this, disconnect the wires and make
sure the ends of the wires on both sides of the cable are isolated from each other and other
wires or loads.
1. Connect the Transmitter with the test leads to the circuit as shown in Figure 4.3.
2. Turn the Transmitter to Loop mode by pressing HIGH button for two seconds. Verify that
the Loop LED is ON.
3. Setup the Receiver to a wire tracing mode (either Quick Scan or Precision Tracing).
Start tracing the cable until the signal stops. To verify the place of the fault, move the
Transmitter to the other end of the wire and repeat tracing from the opposite end. If the
signal stops at the exact same location the fault has been located.
Note: This method will be affected by signal cancellation effect. Expect a relatively weak signal.

4.4 Tracing Wires in Metal Conduit

The Receiver is unable to pick up the signal from a wire through a metal conduit. The metal
conduit will completely shield the tracing signal.
Note: The Receiver will be able to detect wires in a non-metallic conduit. For these
applications follow general tracing guidelines.
To trace wires in a metal conduit:
1. Use the Quick Scan or Precision Tracing modes.
2. Open junction boxes and use the Receiver Tip Sensor to detect which wire in the
junction box is carrying the signal.
3. Move from junction box to junction box to follow the path of the wire.
Note: Applying a signal directly to the conduit will send the signal through all the conduit
branches, making tracing a particular conduit path impossible.
Figure 4.3: Tracing a cable to find shorts
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