The XHDD503C+ cable fault pinpointer uses the acoustic-magnetic synchronization principle of vibration pickup and electromagnetic induction to determine the exact location of a cable fault. A high-voltage pulse generator induces a flashover discharge at the fault point; the resulting vibration waves, sound waves and electromagnetic waves are collected by the dedicated probe, intelligently processed by the main unit, and shown as a fault waveform with sound output. The operator then uses hearing and vision together to confirm the precise fault location — directly above the cable, within the roughly measured range.
The locator is suitable for low-resistance, short-circuit, open-circuit and broken-circuit faults in power cables, coaxial cables and low-voltage cables of different voltage levels, cross-sections and media, as well as leakage and flashover high-resistance faults. Its acoustic-magnetic positioning complies with DL/T 849.2-2019 (General Technical Conditions for Special Testers for Power Equipment, Part 2: Cable Fault Locator) and GB/T 18268.1.
Who It Is Built For
For the flashover-pinpointing stage, when a rough distance must become a spot on the ground
This pinpointer is not a path tracer or a cable identifier; it takes over at the point where the route is already known and the fault must be fixed to one place before the ground is opened. It serves two settings in particular:
Cable fault test engineers and field crews who run a high-voltage pulse generator at the flashover stage. After the rough measurement gives a distance, these crews need to convert it into an exact spot. The acoustic-magnetic synchronization method measures the time difference between the electromagnetic signal (which travels far faster than sound) and the discharge sound, so the smallest time difference marks the fault below — a screen-based confirmation that replaces the traditional ear-only listening method, which is fleeting and hard to read for less experienced operators.
Urban and municipal distribution network operation teams who must minimise excavation. In built-up areas an unnecessary trench is expensive and disruptive, so the pinpoint has to be trustworthy. Along with the approaching-fault prompt and path-deviation indication, the digital, noise-reducing probe helps the crew commit to one spot with confidence, even on high-resistance or leakage faults where the discharge sound is weak.
Product Features
High-brightness touch screen (480 × 850, 350 nits) that stays visible even in sunlight.
Acoustic-magnetic synchronous positioning technology that automatically calculates the acoustic-magnetic time difference.
Automatic and manual adjustment of the sound signal gain and trigger values.
Background noise reduction technology with a choice of filtering options, plus BNR background noise reduction and mute (dumb) noise reduction.
Path deviation indication and an approaching-fault-point prompt.
Highly sensitive, noise-resistant, fully digital fixed-point probe.
Multi-layer physical isolation signal sensors, waterproof rating IP65.
Built-in high-capacity lithium battery with ultra-long standby time and a fast charger.
Compact and lightweight, easy to operate, with a simple human-machine interface.
Working Principle
The device uses the acoustic-magnetic synchronization method for precise fault location, based on the traditional acoustic method with electromagnetic signal detection added. When the high-voltage generator discharges through the faulty cable, the sound produced by the discharge at the fault point travels to the ground; it is picked up by a highly sensitive probe, amplified, and heard through headphones as a "pop" sound. The probe's built-in magnetic field induction coil receives magnetic field signals in real time, and because the magnetic field propagates far faster than sound, the distance to the fault point is found from the time difference between the electromagnetic and sound signals. By continuously moving the probe, the point with the smallest acoustic-magnetic time difference is found — the exact fault location lies below that point.
Traditional acoustic locators rely only on headphones or a moving meter pointer to distinguish the discharge sound at the fault point; because that sound is fleeting and easily confused with ambient noise, it is often difficult for less experienced operators. The acoustic-magnetic synchronization method avoids these problems.
Choosing the Right Filter for the Site
The sound of an impact discharge at a fault point is strongly affected by the medium and the distance the sound has travelled. Under hard coverings such as cement or stone slabs, sound travels faster and the high-frequency component is stronger; under sand or mud, the high-frequency component is attenuated and the low-frequency component dominates. Select the filter to match the site:
| Filter |
Frequency |
Best applied when |
| Full-Pass |
100 Hz – 1600 Hz |
Maximum operating bandwidth, for hearing the impulse discharge sound with minimal interference; low-frequency interference at high volume can make the time difference harder to read. |
| Low-Pass |
100 Hz – 300 Hz |
When the measurement point is far from the fault, or the overburden is loose soil or sand (muffled sound). |
| High-Pass |
160 Hz – 1600 Hz |
On hard surfaces and close to the fault point, where low-frequency background noise is reduced to the maximum. |
| Band-Pass |
200 Hz – 600 Hz |
A trade-off between low-pass and high-pass, useful for acoustic-magnetic time-difference measurement when low-pass filtering is used. |
Using the Instrument Components
The set comprises the cable fault locator (main unit), the probe (with connecting rod, base, ground pin, probe connector and disc connector), headphones, a 7-core shielded signal cable, a charger and a multi-functional wrench.
Fixed-point steps
Assemble the probe, connect it to the sensor port, and plug the headphones into the headphone jack.
In the selected area (within about ±50 m of the rough measurement), place the sensor flat on the ground directly above the cable, pointing along the direction of the cable.
Begin with a low threshold, high gain and high volume; observe the waveform and listen. If nothing is heard after several discharges, increase the probe movement distance.
Once sound and acoustic-magnetic waveforms appear, move the probe every 1–2 m, listening to each point for at least two discharge cycles, and note the changes in sound, time difference and waveform.
When the signal fades again, go back and relocate with a higher threshold, lower gain and lower volume; the point where the sound and waveform are greatest and the time difference is smallest is the fault point.
Because the speed of sound in the surrounding medium and the exact burial depth are hard to know, the time difference is only a rough estimate. When deciding the location, treat sound as the primary factor and the time difference as the secondary factor.
Technical Specifications
| Filtering Parameters |
Full-pass 100–1600 Hz; band-pass 200–600 Hz; low-pass 100–300 Hz; high-pass 160–1600 Hz |
| Channel Adjustment |
Sound and magnetic signals in 8 levels; signal trigger threshold 0–99 levels |
| Sound Output |
Gain 16 levels (0–112 dB); impedance 350 Ω |
| Detection Range |
0.00 – 99.99 ms |
| Filtering Method |
Fifth-order superposition filter |
| Detection Accuracy |
Positioning ≤ 0.1 m; path ≤ 0.5 m |
| Working Power Supply |
3.7V, 18650 cells × 4 |
| Standby Time |
More than 8 hours |
| Ambient Temperature |
-25 to 65 ℃; relative humidity ≤ 90% |
| Waterproof Rating |
IP65 |
Precautions and Common Faults
Before and during use
Read the manual and follow the relevant precautions; violent impacts to the instrument are strictly prohibited. Charge the unit when the battery level shown on the main unit screen falls below 20%. The probe is a sensitive element and must not be disassembled without authorisation. Do not clean the LCD with corrosive solvents such as chemical solvents or alcohol — use a semi-dry, lint-free cloth soaked in warm water, then a dry microfiber cloth. Do not place the sensor directly on the cable body for pinpointing: this produces a faint crackling sound anywhere along the cable (vibration from the instantaneous discharge of a large current, or a weak discharge from oxidation/rust at the armour overlap) that cannot be used for pinpointing.
Common faults
Unable to test magnetic field signals. Check that the main unit battery has sufficient power, that the magnetic field channel gain is set appropriately, that the connection between the main unit and the probe is reliable, and retest whether the path is correct.
No sound from the headphones when the probe is positioned or tapped. Check that the main unit battery has sufficient power, that the volume/gain setting is appropriate, that the main unit-to-probe connection is reliable, and that the headphone connection is reliable.
If the instrument malfunctions, contact the manufacturer promptly — do not disassemble it at will.
Frequently Asked Questions
Q1. What kind of faults can the XHDD503C+ locate? It is suitable for low-resistance, short-circuit, open-circuit and broken-circuit faults in power cables, coaxial cables and low-voltage cables of different voltage levels, cross-sections and media, as well as leakage and flashover high-resistance faults. It pinpoints the fault directly above the cable within the roughly measured range.
Q2. How does the acoustic-magnetic synchronization method work? A high-voltage pulse generator induces a flashover discharge at the fault point. The discharge produces sound waves and electromagnetic waves; the probe's magnetic field induction coil receives the magnetic signal in real time, and because the magnetic field travels far faster than sound, the distance to the fault is derived from the time difference between the two. The point with the smallest time difference is where the fault lies below. This replaces the traditional ear-only listening method.
Q3. Which filter should I choose? Use full-pass (100–1600 Hz) for the maximum bandwidth, low-pass (100–300 Hz) when the point is far from the fault or the overburden is loose soil or sand, high-pass (160–1600 Hz) on hard surfaces and close to the fault, and band-pass (200–600 Hz) as a trade-off between low-pass and high-pass.
Q4. What should I keep in mind while pinpointing? Start with a low threshold, high gain and high volume, then relocate with a higher threshold, lower gain and lower volume. Move the probe every 1–2 m and listen to each point for at least two discharge cycles. Because the speed of sound in the medium and the burial depth are uncertain, always treat sound as the primary factor and the time difference as the secondary factor. Do not place the sensor directly on the cable body.
Q5. There is no magnetic signal, or no sound in the headphones—what should I check? Check whether the main unit battery has sufficient power, whether the relevant gain and volume settings are appropriate, whether the connection between the main unit and the probe is reliable (and, for the no-sound case, the headphone connection), and retest whether the path is correct.
Need to turn a rough fault distance into an exact spot on the ground?
Contact XZH TEST for configuration advice and a quotation on the XHDD503C+ acoustic-magnetic cable fault pinpointer.
Your message must be between 20-3,000 characters!
english
français
Deutsch
Italiano
Русский
Español
português
Nederlandse
ελληνικά
日本語
한국
العربية
हिन्दी
Türkçe
indonesia
tiếng Việt
ไทย
বাংলা
فارسی
polski
Overall Rating
Rating Snapshot
The following is the distribution of all ratingsAll Reviews