XHHG523L Cable Outer Sheath Fault Locator Overview
The output voltage of the high-voltage cable outer sheath fault locator is 10kV and below, fully meeting the cable outer-sheath withstand test requirements of the Chinese national standard GB50150-2006, including acceptance and preventive tests of cable outer sheaths suitable for cross-bonding systems as well as fault location of cable outer sheaths. It quickly and accurately finds outer-sheath grounding faults and hidden hazards such as excessive leakage current in 10kV-500kV single-core and three-core high-voltage and extra-high-voltage cables, and can also carry out 5kV-10kV, 1-minute DC withstand tests on HDPE and PVC cable outer sheaths. It is an essential dedicated instrument for the cable equipment maintenance of 10kV-500kV single-core and three-core high-voltage and extra-high-voltage cable operating units, extra-high-voltage cable engineering companies and power transmission & transformation engineering companies.
Who It Is For (Target Audience)
The XHHG523L is positioned for the on-site pinpointing and withstand stage of cable outer-sheath work — once the approximate fault section is known, it is used to pinpoint the exact jacket fault location, and to run the jacket DC withstand test on site. It is engineered for field cable service and maintenance crews that work directly on 10kV-500kV high-voltage and extra-high-voltage cables, for extra-high-voltage cable engineering companies and power transmission & transformation engineering companies that carry out jacket acceptance and preventive testing, and for cable asset owners and industrial, rail, metro and substation users that maintain their own high-voltage cable jackets. It is used in both directly buried applications (step voltage method) and tunnel-laid applications (current method), as well as for 5kV-10kV, 1-minute DC jacket withstand tests on HDPE and PVC sheaths. Unlike the other instruments in the same category, which combine jacket fault ranging with withstand testing, this device is a dedicated portable locator: it has no bridge ranging section and instead focuses on pinpointing the jacket ground fault on site and performing the jacket withstand test, in one portable unit.
Product Features
Automatic over-current, over-voltage and over-heat protection.
Zero-position start protection for greater safety and reliability.
Unique self-discharge design: as soon as the high-voltage output is cut off, its own high voltage becomes zero.
Dual pointer meters for current and voltage, intuitive and clear.
One-key switching between localization mode and withstand mode, fast and convenient.
The test range has no blind area.
The receiver sensitivity is adjustable, making localization more convenient.
Over-current protection switch, convenient for use in both withstand mode and localization mode.
Technical Specifications
| Item |
Specification |
| Input voltage |
AC 220V (±10%), 50Hz (±2Hz) |
| Output voltage |
0~10kV (square wave), adjustable |
| Output current |
0~200mA |
| Output capacity |
2kVA |
| Frequency adjustment |
Min: 0.2Hz, Max: 5Hz (range adjustable) |
Working Principle
Localization function: the AC 220V mains supply is subjected to full-wave rectification to achieve an excellent conversion, transforming it into the high-power special signal required for identification; this signal is applied to the cable to be localized through the connecting line, and the “step voltage method” or the “current method” can be used to precisely pinpoint the cable fault.
Step voltage method: if a buried cable has a grounding fault, the potential-difference method can be used to find the fault point. A test voltage is applied between the test point of the faulty cable and the ground, so that a distribution electric field concentric with the entry point forms around the cable's entry point into the ground. There is no potential difference between any points of the same radius in this field, but there is a potential difference between any two points of different radii, and when the spacing between the two points is fixed, the closer the two points are to the center, the stronger the potential difference. By moving the two points A and B gradually toward the center, the potential difference becomes zero when the fault point is exactly midway between A and B; if the movement continues past the fault point, the polarity of the potential difference reverses, so moving back and forth allows the grounding point to be judged accurately.
Current method: if a tunnel cable has a grounding fault, the opposite current directions before and after the fault point can be used to find the fault point. A pulsed high-voltage signal is applied to the faulty cable so that the fault point discharges; the currents before and after the fault point then have opposite polarities while the current at the fault point is the smallest. A receiving clamp is used to judge the direction of the current before and after the fault point: clamping the receiving clamp on the cable, the receiving box indicates a direction, and if the movement continues past the fault point the current polarity reverses, so moving back and forth allows the grounding point to be judged accurately.
Withstand function: switch the function key to the withstand function to output 0-10kV for a withstand test on the cable.
Instrument Composition
Cable outer sheath fault locator: the unit for fault localization or withstand testing.
High-voltage connecting line: connects the high-voltage output of the main unit to the core of the cable under test.
Power line: the working power line of the instrument.
Receiver: the unit that receives the signal during fault localization.
Fuse: 8A fuse, spare fuse for the AC 220V supply system.
Ground wire: the grounding wire of the instrument.
Receiving clamp: clamp-type receiver.
A-frame: used with the step voltage method.
Main PanelGrounding column: grounding point of the instrument, for safety protection.
Receiver PanelPosition switch: “0” position means off; “I” position can be used for step voltage test mode and receiving clamp test mode, suitable for test environments with a weaker input signal (there is an internal amplifier circuit); “II” position can only be used for step voltage test mode, suitable for test environments with a stronger input signal (there is no internal amplifier circuit).
Main Operation
1.Insert the red high-voltage line into the “high-voltage output” terminal with the other end connected to the metal sheath or armoring and the “ground” reliably connected; never connect wiring while the unit is on.
2.After wiring is complete, connect the AC 220V supply and switch on.
3.Confirm the on-site cable condition and that the wiring is correct; before starting, check whether the voltage adjustment has been turned counter-clockwise to zero — when the start button lamp is lit it indicates the zero position has been reached, and the unit cannot be started if it has not been zeroed.
4.Press the start button; the stop button lamp comes on. Use the localization/withstand function switch button to select the working state — localization mode (green lamp) or withstand mode (red lamp). In localization mode, the frequency adjustment knob can be turned to adjust the output frequency.
5.Turn the voltage adjustment clockwise and watch the voltmeter and ammeter to select a suitable output voltage.
6.After the test, turn the voltage adjustment counter-clockwise to the zero position, press the stop button so the instrument stops working, and then switch off.
7.Only after discharging the faulty cable with high voltage may the test wiring be removed.
Use Examples
Localization — step voltage method (for pinpointing outer-sheath faults of directly buried cables, with the main unit transmitting a signal in localization mode to ensure a continuous pulse current output): install the A-frame and connect it to the receiver with the A-frame connecting line; set the receiver position switch to “I” (weaker signal) or “II” (stronger signal), zeroing the microammeter with the zeroing knob in position “I” (in “II” position the zeroing knob has no effect); along the cable route, directly above the cable within the rough measuring range, insert the A-frame probes into the ground and observe the magnitude and direction of the ammeter, using the adjustment knob to set a suitable pointer swing; keep the adjustment knob and the front-to-back order of the A-frame probes unchanged and keep moving the A-frame forward above the cable, first finding the section where the polarity changes and then the point where the pulsating signal is “0” or reversed, which is the fault point; when finished, set the receiver position switch to “0”, switch off the high-voltage pulse signal and discharge the cable and capacitor.
Localization — current method (for pinpointing outer-sheath faults of cables laid in tunnels, with the main unit transmitting a signal in localization mode): connect the current receiving clamp to the receiver; set the receiver position switch to “I” (or “II” when the current is strong) and zero the microammeter with the zeroing knob; within the rough measuring range, clamp the current receiving clamp on the cable and observe the magnitude and direction of the ammeter, using the adjustment knob to set a suitable pointer swing; keep the adjustment knob and the direction of the receiving clamp unchanged and keep moving the clamp forward, first finding the section where the polarity changes and then the point where the pulsating signal is “0”, which is the fault point; when finished, set the receiver position switch to “0”, switch off the high-voltage pulse signal and discharge the cable and capacitor.
Withstand mode: insert the red high-voltage line into the “high-voltage output” terminal with the other end connected to the metal sheath or armoring and the “ground” reliably connected (never connect wiring while the unit is on); after wiring is complete, connect the AC 220V supply and switch on; confirm the on-site cable condition and that the wiring is correct, and before starting check whether the voltage adjustment has been turned counter-clockwise to zero; select the withstand mode with the function switch button (red lamp); press the start button and the stop button lamp comes on; turn the voltage adjustment clockwise and watch the voltmeter and ammeter to select a suitable output voltage; after the test, turn the voltage adjustment counter-clockwise to the zero position, press the stop button, and then switch off; only after discharging the faulty cable with high voltage may the test wiring be removed.
Notes and Common Issues
Do not touch the high-voltage connecting line and the cable under test during testing, to avoid high-voltage injury.
Never switch on the unit while connecting cables, and switch off the power promptly after the test.
The instrument cannot be started when the voltage adjustment is not at the zero position.
If the receiver cannot be zeroed, open the rear cover of the receiver and check whether the 9V battery has power.
The grounding must be reliable.
Warranty: within one year from the date of purchase, free repair is provided for product quality problems, with lifetime maintenance and technical service.
FAQ Q1: What is the XHHG523L used for?
It is a high-voltage cable outer sheath fault locator with an output of 10kV and below. It is used to quickly and accurately find outer-sheath grounding faults and excessive leakage-current hazards in 10kV-500kV single-core and three-core high-voltage and extra-high-voltage cables, fully meeting the cable outer-sheath withstand test requirements of GB50150-2006, including acceptance and preventive tests of outer sheaths suitable for cross-bonding systems.
Q2: What is the output capability?
The input voltage is AC 220V (±10%), 50Hz (±2Hz); the output voltage is 0~10kV (square wave) and adjustable; the output current is 0~200mA; the output capacity is 2kVA; and the frequency adjustment ranges from a minimum of 0.2Hz to a maximum of 5Hz (adjustable). It can also carry out 5kV-10kV, 1-minute DC withstand tests on HDPE and PVC cable outer sheaths.
Q3: How does it pinpoint the fault point?
In localization mode the AC 220V supply is converted into a high-power special signal applied to the cable, and the fault is pinpointed with the step voltage method for directly buried cables (with the A-frame) or the current method for cables laid in tunnels (with the receiving clamp), following the polarity change and then the point where the pulsating signal is zero.
Q4: What protection and display features does it provide?
It has over-current, over-voltage and over-heat automatic protection, zero-position start protection, and a unique self-discharge design (once the high-voltage output is cut off, its own high voltage becomes zero). It uses dual pointer meters for current and voltage, allows one-key switching between localization mode and withstand mode, has no blind area in the test range, and provides an over-current protection switch and adjustable receiver sensitivity.
Q5: What are the physical specifications and what is included?
The dimensions are 540L × 310W × 460H and the weight is 35kg. The instrument comes with the main unit, a high-voltage connecting line, a power line, a receiver, an 8A fuse (with spare), a ground wire, a receiving clamp and an A-frame.
