1. Preparation
(1) Safety Measures: Ensure the cable is de-energized and fully discharge it using a discharge rod.
(2) Instrument Check: Verify the tester has sufficient battery, connection cables are intact, and accessories (e.g., surge generator, HV equipment) are functional.
(3) Tool Preparation: Carry insulated gloves, a multimeter, a cable route tracer (optional), and other auxiliary tools.
2. Connection Methods
(1) Low-Voltage Pulse Method (For low-resistance or open faults):
Connect the tester's output terminal (red clip) to the faulty cable core and the black clip to the cable sheath or ground wire.
Ensure the cable's far end is open and not grounded.
(2) High-Voltage Surge/Flashover Method (For high-resistance faults):
Use a high-voltage generator to create a breakdown discharge at the fault point.
The tester collects the discharge signal via a coupler; connect the sync trigger lead.
3. Parameter Settings
(1) Wave Velocity Calibration: Enter the cable's wave propagation velocity (Reference values: ~160 m/μs for PVC-insulated cables, ~172 m/μs for XLPE cables).
(2) Range Selection: Set the test range based on cable length (e.g., 0-1000m or 0-5000m).
(3) Pulse Width: Use a narrow pulse (e.g., 0.1μs) for low-resistance faults and a wide pulse (e.g., 2μs) for high-resistance faults.
4. Testing Operation
(1) Power on the tester and select the appropriate mode (e.g., "Low-Voltage Pulse" or "Surge Method").
(2) Observe the waveform on the screen: A normal cable shows the transmitted pulse and the end reflection; a fault point appears as an anomalous reflection (polarity inversion or waveform distortion).
(3) Measure the time difference between the transmitted pulse and the fault reflection pulse using the cursor. Calculate the fault distance: Fault Distance = (Time Difference × Wave Velocity) / 2.
5. Data Analysis
(1) Compare waveforms from multiple tests to eliminate interference signals.
(2) Correlate results with the cable laying route diagram to locate the approximate fault point.
