Amprobe AT-7000 - Manual (Page 26)

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4. sPeciaL aPPLications
4.1 GFCI-Protected Circuit Wire Tracing
Connecting AT-7000-T transmitter to GFCI protected circuits.
Connecting a transmitter to an energized GFCI protected circuit using separate ground
method will trip the GFCI protection. Use following methods to work with GFCI protected
circuits (for de-energized GFCI-protected outlet that is not tripped, you can connect test
leads directly to the outlet contacts using de-energized TIP SENSOR mode)
Method 1 – Bypass the GFCI circuitry to avoid tripping GFCI:
(for energized GFCI-protected outlets only)
• Remove the protective receptacle wall plate
• Using the alligator clip attach a red test lead to the screw connecting the energized hot
wire to the receptacle
• Connect green test lead using separate ground method as described in Energized TIP
SENSOR mode
• Perform tracing as described in one of the Energized modes: SMART SENSOR, TIP
SENSOR or BREAKER.
Method 2 – Do NOT use separate ground to avoid tripping GFCI:
(for GFCI-protected outlets and breakers)
• Connect transmitter test leads to Neutral and Hot wires.
• Perform tracing as described in one of the Energized modes: SMART SENSOR, TIP
SENSOR or BREAKER.
Note: This type of connection causes signal coupling and reduces signal strength. If the
signal is too weak or untraceable, use Method 3.
Method 3 - De-energize the circuit:
(for GFCI-protected breakers)
• De-energize the circuit
• Connect a transmitter directly to the wire as described in De-Energized TIP SENSOR
mode
• Perform tracing as described in the desired De-Energized mode (TIP SENSOR for wire
tracing or BREAKER for breaker identification).
4.2 Finding Breaks/Opens
It is possible to pinpoint the exact location where the wire is broken using the de-energized
TIP SENSOR mode, even if wire is located behind walls, floors or ceilings:
1. Make sure that wire is de-energized.
2. Use steps described in the De-Energized TIP SENSOR mode to connect the transmitter
and perform tracing. (see section 3.2)
The tracing signal generated by the AT-7000-T transmitter will be conducted along the wire
as long as there is continuity in the metal conductor. To find the place of fault, trace the
wire until the signal stops. To verify the place of the fault, move transmitter to the other
end of the wire and repeat tracing from the opposite end. If signal stops at the exact same
location you have found the place of the break.
Note: If the place of fault is not found, the open 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.