HM6050D Multi-Pulse Cable Fault Locator Operating Guide
I.Precautions:
1. Low resistance / short circuit (<100Ω): Employ low-voltage pulse method with wave velocity 160–170m/μs and pulse width 0.1–0.2μs
2. High resistance / flashover (>100kΩ): Employ multiple-pulse method with high-voltage generator, maintaining wave velocity as above with pulse width 2μs
3. Distance-to-fault formula: Distance = Wave velocity (m/μs) × Time difference (μs) ÷ 2
4. Safety precautions: High-voltage operations must be earthed; voltage rise ≤5kV/s; single operation of multiple-pulse coupler ≤5 minutes
II. Fault Prediction (Using Insulation Resistance Tester)
1. <100Ω: Low resistance / Short circuit → Low-voltage pulse method
2. 100Ω–100kΩ: Medium resistance → Multiple pulse method
3. >100kΩ: High resistance / Flashover → Multiple pulse method
III.Multiple Pulse Method (High Resistance / Flashover)
1. Wiring
- High-voltage generator → High-voltage capacitor → Multiple pulse coupler → Faulted phase core wire
- Coupler → Host signal input terminal
- High-voltage generator tail end → Reliably earthed
- Cable far end: Floating
2. Host Configuration
- Mode: Select Multiple Pulse (8 samples)
- Wave Velocity: Same as low-voltage pulse (160m/μs)
- Pulse Width: 2μs
- Sampling Frequency: ≥24MHz (to ensure accuracy)
3. High-Voltage Operation
- Power-up: Switch on host first, then high-voltage generator
- Voltage Rise: Rate '≤5kV/s', rise to 6–8kV (not exceeding 3–5 times cable rated voltage)
- Triggering: Press the main unit start button to initiate high-voltage discharge; fault point flashovers occur (visible sparks / audible discharge sounds)
- Sampling: The main unit automatically acquires 8 sets of pulse waveforms; single operation ≤5 minutes (protecting the coupler)
- Shutdown: First press the main unit stop button, then reduce voltage, switch off the high-voltage power supply, and finally switch off the main unit
4. Waveform Analysis
- Page: Select a clear, oscillation-free M-shaped waveform
- Cursor: Position at the incident wave start point and the reflected wave inflection point
- Reading: Instrument displays fault distance; repeat 2–3 times and take the average
- Error: ≤1% is acceptable
