TDR Cable Fault Pre-Locator XHGG501A2 | 68 km Ranging, 400 MHz Sampling, 0.1 m Resolution

The XHGG501A2 is a traveling-wave cable fault pre-locator built around a 12.1-inch industrial touchscreen computer. It measures wave propagation velocity, cable length and fault distance, and gives a maintenance team a reliable first-pass distance reading before a pinpointing survey begins.

The instrument combines an industrial control computer with integrated circuits and a built-in high-capacity lithium-ion battery, so filtering, signal acquisition, data processing, waveform display and waveform analysis are all handled in one unit. Typical use is a plant feeder that has tripped: the operator selects the cable type and test method, samples the waveform, interprets the echo and reads the fault distance from the screen.

The pre-locator is applied to low-resistance, short-circuit, open-circuit and broken-conductor faults, and to high-resistance leakage and high-resistance flashover faults, in power cables, high-frequency coaxial cables, street light cables and buried wires of various cross-sections and media.

Technical parameters follow GB/T 18268.1 (immunity requirements for testing equipment at industrial sites), DL/T 849.1-2019 (general technical conditions for special testers for power equipment, Part 1: cable fault flash tester) and JJF1042-2020 (calibration specification for cable fault testers).

• 12.1-inch industrial-grade computer with touchscreen operation; measurements are taken and read on the same screen.
• Two test methods in one instrument: the low-voltage pulse method and the impulse high-voltage flashover method.
• Wave velocity measurement, cable length testing and cable fault distance testing.
• Fully automatic continuous sampling for timely waveform capture.
• Large waveform storage: field waveforms are stored in the instrument in a specified order and recalled for observation at any time.
• Waveform comparison against previously saved waveforms, and waveform printing through the standard printer USB interface.
• Cable type presets for cross-linked polyethylene, polyvinyl chloride, rubber-sheathed and oil-impregnated paper cables, plus custom propagation velocity for other cable types.
• Length range selection for short (<1 km), medium (<3 km) and long (>3 km) cables.
• Built-in polymer lithium battery, allowing open-circuit and low-resistance short-circuit testing where no mains supply is available.
• Ultra-high brightness LCD display that remains readable in direct sunlight.

Low-voltage pulse method

A low-voltage pulse is applied to the cable under test and reflected at the fault point. The instrument processes the reflected signal and displays a waveform; the fault distance is obtained by analysing that waveform. Low-resistance and open-circuit faults are read from the polarity of the echo at the fault point.

High-voltage flashover method

For high-resistance faults the instrument works with a high-voltage source. In the direct flashover method a DC high-voltage supply raises the voltage on the faulty cable until flashover discharge occurs at the fault point; in the impulse flashover method a high-voltage pulse signal source drives the discharge. The reflected signal is picked up by the sampler and sent to the instrument, which displays the waveform for distance analysis.

Field note: high-voltage flashover sampling is strictly prohibited while the instrument is powered from AC 220 V. The separate sampler is used only in the high-voltage flashover mode, never while the software is set to the low-voltage pulse mode.

Sampled waveforms can be stored on the instrument in the order they were taken, reopened later and placed side by side with a stored waveform for comparison. Waveforms and test records can be printed through the USB interface; where an external printer driver is not compatible with the instrument, the file is copied to a USB drive from the instrument’s local disk and printed from an office computer.

The instrument carries a one-year warranty from the date of purchase for product quality issues, with lifetime maintenance and technical service. If the instrument shows any abnormality or malfunction, contact the manufacturer so the most convenient and effective solution can be arranged.

1. Which cable faults can the XHGG501A2 pre-locate?

Open-circuit and broken-conductor faults, low-resistance faults and short circuits are tested with the low-voltage pulse method. High-resistance leakage faults and high-resistance flashover faults are tested with the high-voltage flashover method together with a high-voltage source and the sampler.

2. What range and accuracy does it deliver?

Ranging range is 68 km or more, minimum resolution is 0.1 m, the test blind zone is 10 m or less, and measurement error is within ±(0.5%×L+1 m), where L is the cable length.

3. Which cable types and lengths are supported?

The instrument is applied to power cables, high-frequency coaxial cables, street light cables and buried wires of various cross-sections and media. Cable presets cover cross-linked polyethylene, polyvinyl chloride, rubber-sheathed and oil-impregnated paper cables, with custom wave velocity for other types; length ranges are selected for cables under 1 km, under 3 km and over 3 km.

4. Can it be used where no mains power is available?

Yes. The built-in 11.1 V lithium battery pack allows open-circuit and low-resistance short-circuit testing without mains supply, and the pack is recharged from AC 110–240 V. High-voltage flashover sampling is strictly prohibited while the instrument is powered by AC 220 V.

5. What is included, and what does the warranty cover?

Each set includes the cable fault tester, stylus, power cord, single Q line, double Q line and sampling box. The instrument is covered by a one-year warranty from the date of purchase for product quality issues, with lifetime maintenance and technical service.

Send us the cable type, the fault symptoms recorded on site and the test method you intend to use, and we will confirm whether the low-voltage pulse method alone is sufficient or whether the high-voltage flashover method with the sampler is required for your case.