Cable Sheath Fault Locator

Electronic No-Load Voltage 7500V High-Resistance Cable Fault Detection Sheath Fault Pre-Location High-Voltage Bridge

The cable outer sheath fault tester is designed based on the MURRAY bridge principle and can be used to locate the breakdown points of various wires and cables and the defect points that have no breakdown but low insulation resistance values.

The equipment uses an electric voltage regulator and an R-type transformer to form a high-voltage constant current source, and the button operation can increase or decrease the voltage. 

The no-load voltage is 7500V, the short-circuit current is 100mA, and a high-sensitivity amplifier and galvanometer are used to indicate balance. It forms a balanced bridge with a proportional potentiometer, and the whole is placed at a high potential.

The measurement cable is a specially designed two-core high-voltage rubber cable. The four-terminal resistance measurement method is used to avoid errors caused by lead resistance. 

The entire panel is at low potential. One-touch operation, enter the cable length and automatically calculate the fault distance. The high voltage source and bridge are integrated in a portable protective box. Therefore, the device has high voltage, light weight, easy operation and safe use.

Technical specification

Packing list

More photos and test site

XHHD523L

With the full deployment of the urban network transformation, many power supply bureaus, construction parties, and even design units encountered 110kV XLPE cables for the first time. Due to time constraints and insufficient experience, many cables failed to pass the withstand voltage test (10kV/ 1min). 

At present, most of the outer sheath is made of HDPE sheath material, which has passed the DC 25kV/5min withstand voltage test in the factory, and the leakage current is as low as tens of μA. Therefore, most of the defects after laying are caused by external force damage during laying, including soil filling and cover. Defects after operation usually include termite bites; water in the grounding box; deterioration of the original defect; moisture penetration of the bifurcated part of the grounding wire reduces the insulation resistance, etc., sometimes because the cable is buried too deep or the surrounding conditions are complicated, so It is very difficult to locate, and some defects cannot be resolved after many years, leaving hidden dangers to the operation.

The output voltage of the high-voltage cable outer sheath fault detector is 10KV and below, including the cable outer sheath handover test and preventive test suitable for cross-interconnect systems and the fault location of the outer sheath of the cable.

Quickly and accurately find hidden dangers of 10kV-500kV single-core and three-core high-voltage and ultra-high voltage cable outer sheath grounding faults and large leakage currents. At the same time, it can perform 5kV-10kV on high-density polyethylene and polyvinyl chloride cable outer sheaths, 1 The minute DC withstand voltage test is a special instrument necessary for the maintenance of cable equipment of 10kv-500kv single-core and three-core high-voltage and ultra-high voltage cable operation units, ultra-high voltage cable engineering companies, and various power transmission and transformation engineering companies.

Main features

1 with over-current, overvoltage, overheating automatic protection function;

2 It is safer and more reliable with zero start protection;

3 Unique self-discharge design, as long as the high-voltage output is cut off, the high-voltage itself will be zero;

4 with current and voltage double pointer meter display, intuitive and clear;

5. One-key switch between positioning mode and withstand voltage mode, which is convenient and quick;

6 There is no blind spot in the test range;

7. The receiver sensitivity is adjustable, which is more convenient for positioning;

8 Over-current protection switch function, withstanding voltage mode and positioning mode are convenient to use.

Technical data 

1 Input voltage: 220V (±10%), 50Hz (±2Hz);

2 Output voltage: 0 ~ 10kV (square wave) adjustable;

3 Output current: 0～200mA;

4 Output capacity: 2kVA;

5 Frequency adjustment: Min: 0.2Hz, Max: 5Hz (range adjustable).

Composition of the instrument

1 Cable outer sheath fault locator: a unit for fault location or withstand voltage test;

2 High-voltage connecting line: connect the high-voltage output end of the host and the cable core under test;

3 Power cord: the working power cord of the instrument;

4 Receiver: the unit that receives the signal when the fault is located;

5 fuse: 8A fuse is used, AC220V power supply system backup fuse;

6 Ground wire: instrument ground wire;

7 Receiver clamp: clamp receiver;

8 A sub-rack: used in the step voltage method.

Packing list

Operation interface introduction

① High voltage output: dedicated DC high voltage output terminal;

② Voltmeter: high voltage output voltage indicating kV meter;

③ Ammeter: output current indicating mA meter;

④ Fuse socket: the place where the fuse of the 220VAC power supply system is installed;

⑤ Power socket: working power supply of the instrument, 220VAC connection port;

⑥ Power switch: "I gear" uses AC220V power supply to supply power to the system; "0 gear" shuts down;

⑦ Frequency adjustment in positioning mode: adjust the pulse output frequency in positioning mode;

⑧ Voltage adjustment: After starting the device, you must first turn the knob counterclockwise to the end. When the high voltage start button light is on, press the start button, and then adjust clockwise to increase the output high voltage from small to large, and adjust counterclockwise to make the output high voltage decrease from large to small;

⑨ High-voltage stop button: When the test is completed or there is an abnormality, press this button to cut off the high-voltage output, the high-voltage light will be off, the stop button light will be on to indicate that there is high-voltage output, and if it is off, it means that there is no high-voltage output;

⑩ High voltage start button: When the start button light is on, it means that the voltage output is in the zero position. When the start button is on, the start button is valid. If the start button light is not on after turning on the power switch, adjust the voltage adjustment knob counterclockwise until the light is on. When the light is on, press this key to start the device and generate high voltage output;

⑪ Overcurrent protection switch: When the blue light is on, the overcurrent protection is turned on, and when the blue light is off, the overcurrent protection is turned off.

⑫ Positioning/withstand voltage function switch button: when the red light is on, it is the withstand voltage function, and when the green light is on, it is the positioning function;

⑬ Grounding column: instrument grounding point, safety protection;

1. Micro-ampere meter: indicates the magnitude and direction of the signal

2. Signal: The input interface of the signal is used to connect the A-frame or the receiving clamp;

3. Zero adjustment: the reference base of the adjustment signal in the "Ⅰ" mode; it does not work in the "Ⅱ" mode;

4. Adjustment: adjust the amplitude of the input signal;

5. Gear switch: "0" gear means shutdown state;

"Ⅰ" file can be used in step voltage test mode and receiving clamp test mode;

It is suitable for the test environment with weak input signal (with amplifying circuit inside);

“Ⅱ” gear can only be used in step voltage test mode;

It is suitable for test environment with strong input signal (no amplifier circuit inside);

Onsite test

With the full deployment of the urban network transformation, many power supply
bureaus, construction parties, and even design units encountered 110kV XLPE cables
for the first time. Due to time constraints and insufficient experience, many cables
failed to pass the withstand voltage test (10kV/ 1min). At present, most of the outer
sheath is made of HDPE sheath material, which has passed the DC 25kV/5min
withstand voltage test in the factory, and the leakage current is as low as tens of μA.
Therefore, most of the defects after laying are caused by external force damage during
laying, including soil filling and cover. Defects after operation usually include termite
bites; water in the grounding box; deterioration of the original defect; moisture
penetration of the bifurcated part of the grounding wire reduces the insulation
resistance, etc., sometimes because the cable is buried too deep or the surrounding
conditions are complicated, so It is very difficult to locate, and some defects cannot be
resolved after many years, leaving hidden dangers to the operation.

The output voltage of the high-voltage cable outer sheath fault detector is 10KV and below, which fully meets the Chinese national standard GB50150-2006 cable outer sheath withstand voltage test regulations, including the cable outer sheath handover We test and preventive test suitable for cross-interconnect systems And the fault location of the outer sheath of the cable. Quickly and accurately find hidden dangers of 10kv-500kv single-core and three-core high-voltage and ultra-high voltage cable outer sheath grounding faults and large leakage currents. At the same time, it can perform 5kv-10kv on high-density polyethylene and polyvinyl chloride cable outer sheaths, 1 The minute DC withstand voltage test is a special instrument necessary for the maintenance of cable equipment of 10kv-500kv single-core and three-core high-voltage and ultra-high voltage cable operation units, ultra-high voltage cable engineering companies, and various power transmission and transformation engineering companies.

Main features

1 with over-current, overvoltage, overheating automatic protection function;
2 It is safer and more reliable with zero start protection;
3 Unique self-discharge design, as long as the high-voltage output is cut off, the high-voltage itself will be zero;
4 with current and voltage double pointer meter display, intuitive and clear;
5. One-key switch between positioning mode and withstand voltage mode, which is convenient and quick;
6 There is no blind spot in the test range;
7. The receiver sensitivity is adjustable, which is more convenient for positioning;
8 Over-current protection switch function, withstanding voltage mode and positioning mode are convenient to use

Technical data 

1 Input voltage: 220V (±10%), 50Hz (±2Hz);

2 Output voltage: 0 ~ 10kV (square wave) adjustable;

3 Output current: 0～200mA;

4 Output capacity: 2kVA;

5 Frequency adjustment: Min: 0.2Hz, Max: 5Hz (range adjustable).

Composition of the instrument

1 Cable outer sheath fault locator: a unit for fault location or withstand voltage test;

2 High-voltage connecting line: connect the high-voltage output end of the host and the cable core under test;

3 Power cord: the working power cord of the instrument;

4 Receiver: the unit that receives the signal when the fault is located;

5 fuse: 8A fuse is used, AC220V power supply system backup fuse;

6 Ground wire: instrument ground wire;

7 Receiver clamp: clamp receiver;

8 A sub-rack: used in the step voltage method.

Operation interface introduction

① High voltage output: dedicated DC high voltage output terminal;
② Voltmeter: high voltage output voltage indicating kV meter;
③ Ammeter: output current indicating mA meter;
④ Fuse socket: the place where the fuse of the 220VAC power supply system is installed;
⑤ Power socket: working power supply of the instrument, 220VAC connection port;
⑥ Power switch: "I gear" uses AC220V power supply to supply power to the system; "0 gear" shuts down;
⑦ Frequency adjustment in positioning mode: adjust the pulse output frequency in positioning mode;
⑧ Voltage adjustment: After starting the device, you must first turn the knob counterclockwise to the end. When the high voltage start button light is on, press the start button, and then adjust clockwise to increase the output high voltage from small to large, and adjust counterclockwise to make the output high voltage decrease from large to small;
⑨ High-voltage stop button: When the test is completed or there is an abnormality, press this button to cut off the high-voltage output, the high-voltage light will be off, the stop button light will be on to indicate that there is high-voltage output, and if it is off, it means that there is no high-voltage output;
⑩ High voltage start button: When the start button light is on, it means that the voltage output is in the zero position. When the start button is on, the start button is valid. If the start button light is not on after turning on the power switch, adjust the voltage adjustment knob counterclockwise until the light is on. When the light is on, press this key to start the device and generate high voltage output;
⑪ Overcurrent protection switch: When the blue light is on, the overcurrent protection is turned on, and when the blue light is off, the overcurrent protection is turned off.
⑫ Positioning/withstand voltage function switch button: when the red light is on, it is the withstand voltage function, and when the green light is on, it is the positioning function;
⑬ Grounding column: instrument grounding point, safety protection;

1. Micro-ampere meter: indicates the magnitude and direction of the signal

2. Signal: The input interface of the signal is used to connect the A-frame or the receiving clamp;

3. Zero adjustment: the reference base of the adjustment signal in the "Ⅰ" mode; it does not work in the "Ⅱ" mode;

4. Adjustment: adjust the amplitude of the input signal;

5. Gear switch: "0" gear means shutdown state;

"Ⅰ" file can be used in step voltage test mode and receiving clamp test mode;

It is suitable for the test environment with weak input signal (with amplifying circuit inside);

“Ⅱ” gear can only be used in step voltage test mode;

It is suitable for test environment with strong input signal (no amplifier circuit inside);

Onsite test