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SG40.4000SMT — Cable Fault Location System

The SG40.4000SMT is a high-energy, trolley-type cable fault location system designed for impulse discharge, fault pinpointing, and withstand voltage testing on low- and high-voltage power cables. It fully complies with DL/T846-2016 and DL/T474-2017 field insulation testing standards.

This system integrates a high-voltage DC source, multi-level energy storage capacitors, automatic discharge modules, and a synchronized switching platform for accurate and controlled high-voltage pulse generation. With selectable voltage levels (10 kV / 20 kV / 40 kV), up to 4000 J discharge energy at each level, and real-time metering, it is one of the most portable, safe, and powerful vehicle-mountable fault location systems on the market.

The SG40.4000SMT also includes advanced protections (zero-start, over-temperature, over-current), grounding detection with tri-color indication, and an internal high-precision waveform sampling module for use with cable fault testers.

Key Features

  • Stepless, uniform high-voltage pulse output (0–10/20/40 kV).

  • Real-time HV side metering ensures safe discharge without stored residual charge.

  • Dual 2.5-level analog meters for clear voltage & current indication (Page 1).

  • Multiple test modes: DC withstand, Single impulse, Cycle impulse (Page 3).

  • Adjustable pulse intervals: 3 s / 6 s / 9 s for periodic operation.

  • Automatic capacitor and sample discharge when testing is stopped.

  • Synchronous capacitor + voltage switching for maximum energy utilization.

  • Zero-position start protection to prevent accidental HV output.

  • Complete grounding detection (green/yellow/red indication).

  • Over-temperature alarm & protection.

  • Overload protection & automatic recovery.

  • Built-in high-precision flashover waveform sampling module.

  • Robust, trolley-type design for field mobility.

Operating Overview

  • Provides controlled HV pulses for cable breakdown pinpointing.

  • Supports withstand voltage tests using the DC mode.

  • Automatic and manual impulse modes selectable via front panel.

  • Internal capacitor bank automatically reconfigures for selected voltage.

  • Ground test function using AC 15 V / 1 A with visual status feedback.

  • High-voltage output, grounding, and sampling terminals clearly laid out (Page 4).

  • Compatible with external TDR/cable fault testers via Q-line connectors.

Panel Overview

Front Panel

  • Voltmeter (8 kV / 16 kV / 32 kV scales).

  • Ammeter for discharge current measurement.

  • Grounding indicator (3-state).

  • Zero-position indicator for safety interlocking.

  • HV output indicator.

  • Discharge interval selector (3–6–9 s).

  • Mode selector: DC / Single / Cycle.

  • Start / Stop / Emergency-stop controls.

  • Manual impulse trigger button.

  • Over-temperature indicator.

  • HV control knob.

  • Voltage range selector (Pull → Rotate → Push).

Side & Rear Panels

  • AC 220 V power input & fuse holder.

  • Signal connector for flashover waveform sampling.

  • Auxiliary grounding terminal.

  • HV output terminal.

  • HV ground & sampling ground terminals.

Applications

  • Accurate cable fault location (low voltage & high voltage).

  • Impulse discharge and burn-through for stubborn cable faults.

  • Withstand voltage testing of underground cables.

  • Field diagnostic work in substations and utility networks.

  • Vehicle-mounted cable testing vans.

  • Industrial maintenance teams working on long-distance cable networks.

Included Accessories

  • Main unit

  • HV output cable

  • Ground cable

  • Discharge rod

  • Power cable

  • Spare fuses

  • Auxiliary ground cable + pin

  • Q-Line and Double Q cables

  • Sampler

  • Optional coupler + HV cables

  • USB communication cable

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