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Xi'an Xu&Hui Electromechanical Technology Co., Ltd.

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China Cable Sheath Fault Testing | 15000V Murray Bridge Cable Fault Locator with No
China Cable Sheath Fault Testing | 15000V Murray Bridge Cable Fault Locator with No

  1. China Cable Sheath Fault Testing | 15000V Murray Bridge Cable Fault Locator with No
  2. China Cable Sheath Fault Testing | 15000V Murray Bridge Cable Fault Locator with No
  3. China Cable Sheath Fault Testing | 15000V Murray Bridge Cable Fault Locator with No
  4. China Cable Sheath Fault Testing | 15000V Murray Bridge Cable Fault Locator with No

Cable Sheath Fault Testing | 15000V Murray Bridge Cable Fault Locator with No

  1. MOQ: 1unit
  2. Price: Negotiable
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Payment Terms T/T
Supply Ability 3000unit/year
Delivery Time 5-8 work days
Packaging Details wooden packaging
Brand Name XZH TEST
Model Number XHGG521C
Certification ISO CE
Place of Origin Xi'an Shaanxi China

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  1. Product Details
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Product Specification

Payment Terms T/T Supply Ability 3000unit/year
Delivery Time 5-8 work days Packaging Details wooden packaging
Brand Name XZH TEST Model Number XHGG521C
Certification ISO CE Place of Origin Xi'an Shaanxi China
High Light ≥15000V Cable Fault Locator ,Rough Measurement Cable Fault Detector ,Portable Cable Tester
XHHG521C High-Voltage Bridge — Cable Fault Locator

The XHHG521C High-Voltage Bridge is a cable fault locator built on the Murray bridge principle. It is designed to locate the breakdown points of laid cables, as well as defect points that have not yet broken down but show an abnormally low insulation resistance. It is equally suitable for locating the defect points of all kinds of cables inside a cable factory.

The unit is powered by a switching-mode high-voltage constant-current source that delivers an open-circuit voltage of 15000V and a short-circuit current of 50mA. A high-sensitivity amplifier and a galvanometer indicate balance and, together with the ratio potentiometer, form a balanced bridge. The measuring cable is a specially designed twin-core high-voltage rubber cable, and a four-terminal resistance measurement method eliminates the error introduced by the lead resistance. The cable is reliably grounded through a braided shielding layer, the panel knobs remain at low potential, and the bridge is operated through an insulated rod. The high-voltage constant-current source and the bridge are integrated in a single portable aluminum-alloy case, which makes the instrument high in voltage yet light in weight, easy to operate and safe to use.

Compared with the wave-reflection method, the bridge-balance method has no blind zone. It is especially suitable for judging short cables and breakdown points close to the cable ends, and it is easy to operate.

Key Features
Adjustable output voltage
Adjustable impulse frequency
Over-current protection
No blind zone within the test range
Signal frequency adjustment
Zero-position protection
Recommended Users and Applications

Unlike wave-reflection (TDR) locators, which leave a blind zone near the cable ends, this high-voltage bridge is built for users who need to locate short cables, near-end breakdown points, high-resistance linear breakdown points and flashover points precisely. It is especially suited to the following users:

1. Professional cable fault locating teams

For example, the cable repair and test teams of large and medium-sized power supply bureaus and of large power-consuming enterprises. Most cable breakdown points can be located roughly and quickly with this high-voltage bridge; used together with the wave-reflection method and a pinpointer, the two methods complement each other and make the location faster and more reliable.

2. Small users

For example, small power supply bureaus and medium-sized power-consuming enterprises. When there are few cables, the routes are fairly clear, the cables are not too long and faults are limited in number, a complete set of wave-reflection locating instruments is costly and demands high operator skill and experience, so it is not the best choice. This instrument is easier to operate, can handle the daily need, and is a better option.

3. Cable manufacturers

Inside the factory it can be used to locate the breakdown points of all kinds of cables; fitted with a digital capacitance meter, it can also find open-wire points. The unit is light in weight and convenient to carry to the site to provide locating service for cable users.

Typical Fault Types It Handles
High-resistance breakdown points of laid cables, especially linear high-resistance breakdown points that are difficult to burn into low resistance, such as a linear high-resistance breakdown at a cable intermediate joint
Flashover-type breakdown points: after breakdown the constant-current source sustains the arc, a stable current passes through the bridge, and the bridge keeps sufficient sensitivity
Defect points that have not broken down but have a low resistance, such as insulation defects that a megohmmeter shows to be of low resistance but that do not break down under operating voltage
Technical Specifications
ParameterValue
Input voltageAC 220V (±10%), 50/60Hz (±2Hz)
No-load voltage≥15000V
Short-circuit current≥50mA
Locating ratio precision±(0.2%·L±1) m
Working Principle

The instrument is based on the Murray bridge. The distances from the two ends of the tested cable to the breakdown point are L1 and L2, the total cable length is L, and the corresponding conductor resistances are R1 and R2. After the cable is connected to the bridge, a balanced circuit is formed; with r1 + r2 = r0, the balance condition gives L1 = P‰·L, where P is the balance adjustment reading.

Instrument Panel Layout
No.ControlFunction
1Power socketAC 220V connection for the instrument working power supply
2Fuse holderHousing for the AC 220V power supply fuse
3AmmeterIndicates the output current (mA)
4VoltmeterIndicates the high-voltage output (kV)
5High-voltage indicatorLights when high voltage is output; when the key is pressed there is no high-voltage output and the light goes out
6Power switchPosition "I" turns on the AC 220V supply; position "0" turns off the system power
7Voltage adjustmentAfter starting, first turn this knob fully counter-clockwise; when the high-voltage indicator lights, turn clockwise to raise the output voltage from low to high and counter-clockwise to lower it
8Zero adjustmentRotate the zero knob to make the galvanometer read zero
9Balance adjustmentAdjust the balance knob until the galvanometer clearly deflects and reads zero (if the pointer is to the left turn clockwise, if to the right turn counter-clockwise); record the reading P1
10Magnification adjustmentCounter-clockwise reduces the magnification; clockwise increases it
11GalvanometerElectrical balance, zero adjustable
12C1P1Connect the reference phase (red clip)
13C2P2Connect the fault phase (black clip)
14Grounding postGrounding point of the instrument for safety protection
Measurement Steps
1.Use a multimeter, a megger or other withstand-voltage device to confirm the breakdown state of the cable, and record the insulation resistance to ground of each core and the residual breakdown voltage, etc.
2.Record the parameters such as the length, model and cross-section of the cable to be tested; patrol along the cable route; at the far end short the fault cable and the auxiliary cable outgoing terminals, and keep one person at the far end for supervision to avoid high-voltage injury.
3.Wiring: reliably connect the grounding terminal of the instrument to the grounding body at the locating site. Connect the grounding rod to the instrument grounding terminal. Connect the measuring head end (black clip) to the fault cable core, and the measuring far end (red clip) to the auxiliary cable core.
4.Zero the bridge (when the high-voltage knob is not at the zero position): turn on the power and rotate the zero knob to make the galvanometer read zero.
5.Connect the power supply to AC 220V.
6.Raise the voltage: turn on the power switch and the power indicator lights. With the high-voltage adjustment knob turned fully counter-clockwise, the instrument starts from the zero position.
7.Slowly turn the high-voltage adjustment knob clockwise and watch the voltmeter and the ammeter until the ammeter exceeds 5mA. If the current is unstable, keep raising the voltage and hold it for a while to form a stable arc or conductive area so that the current stays stable during the test.
8.Balance adjustment: turn the magnification knob clockwise and increase the sensitivity step by step until the galvanometer clearly deflects but not excessively; rotate the adjustment knob to make the galvanometer read zero (if the pointer is to the left turn clockwise, if to the right turn counter-clockwise). Record the reading.
9.Lower the voltage and discharge. Swap the measuring clips and repeat steps 4 to 10 to obtain another reading P2; there should be P1 + P2 = 1000.
10.Calculation: the fault point position X = 2 * L * P1‰. Pay special attention to the "2" in the formula: the auxiliary cable doubles the cable length involved in the calculation.
Notes for Accurate Measurement
Interference may affect the galvanometer zero. You can re-zero at the final sensitivity position: reduce the test voltage to zero, keep everything else unchanged and zero it, then raise the voltage again and adjust the balance; the value will be more accurate.
When a core of a different cross-section is used as the auxiliary cable, convert to the length of the fault cable at the end. If the fault cross-section is Sx and the auxiliary cable is S, the formula becomes X = P1‰ * (1 + Sx/S) * L.
If all three cores of a three-core cable break down or short to each other, choose the core with the best insulation resistance as the auxiliary cable.
The larger the current through the bridge, the higher the sensitivity. The larger the cable conductor resistance, the higher the sensitivity: that is, a thin and long cable has a higher sensitivity while a thick and short cable has a lower sensitivity. For a cable with a large cross-section and a short length, increase the current as much as possible and use a higher amplifier sensitivity.
Safety Precautions
Read this manual carefully and observe the relevant precautions.
The instrument can be used indoors and outdoors, but avoid rain, corrosive gases, heavy dust and high temperatures.
The operator should have general knowledge of using electrical equipment or instruments.
This is a high-precision instrument; avoid severe vibration.
Repair, care and adjustment of the instrument should be carried out by professionals.
The test voltage must never exceed 15kV.
During the test, do not touch the high-voltage connection line or the cable under test, to avoid high-voltage injury.
Never switch on the power while connecting the cables; switch off the power after the test.
The instrument cannot be started when the voltage adjustment is not at the zero position; before switching on, make sure the voltage adjustment knob is at the zero position.
Use the instrument only when at least two people are present: one connects the wiring and the other checks it, and the test starts only after the connection is confirmed correct.
The grounding terminal of the instrument must be reliably grounded, using a dedicated grounding line, preferably clamped to a test-field grounding post, an electrical cabinet grounding bar or the base of mechanical equipment.
During and after the test, before touching any high-voltage part, discharge first and finally hang up the grounding line.
Packing List
ItemQuantity
Main unit1
Output line2
Power line1
Ground line1
Short-circuit line1
After-Sales Service

The instrument is repaired free of charge within one year from the date of purchase for quality problems, and repair and technical service are provided for life. If the instrument is found to be abnormal or faulty, please contact us so that we can arrange the most convenient and effective solution for you.

Mailing address: Building B8-01, Phase I, Ronghao Industrial City, No. 2098 Weiyang 9th Road, Gaoling District, Xi'an, China.
Consignee: Xi'an Xuzhihui Electromechanical Technology Co., Ltd.
Service telephone: 400-029-0829

FAQ
Q1. What types of cable faults can the XHHG521C high-voltage bridge locate?

It locates the breakdown points of laid cables as well as defect points that have not yet broken down but show an abnormally low insulation resistance. It is especially effective for high-resistance linear breakdown points that are difficult to burn into low resistance (such as a linear high-resistance breakdown at a cable intermediate joint), flashover-type breakdown points, and low-resistance insulation defects that do not break down under operating voltage. It is also used inside cable factories for defect-point location.

Q2. Does the bridge-balance method have a blind zone, and how accurate is it?

Compared with the wave-reflection method, the bridge-balance method has no blind zone. It is especially suitable for judging short cables and breakdown points close to the cable ends. The locating ratio precision is ±(0.2%·L±1) m, where L is the cable length.

Q3. What are the output voltage and current, and what input power is required?

The high-voltage constant-current source provides a no-load voltage of ≥15000V and a short-circuit current of ≥50mA. The instrument is powered by AC 220V (±10%), 50/60Hz (±2Hz), and the test voltage must never exceed 15kV.

Q4. How many operators are required, and how is safety ensured?

At least two people must be present: one connects the wiring and the other checks it, and the test starts only after the connection is confirmed correct. The panel knobs stay at low potential and the bridge is operated through an insulated rod, and the cable is reliably grounded through a braided shielding layer. During and after the test, discharge before touching any high-voltage part, and always use a reliable dedicated grounding line.

Q5. What is included in the package, and what after-sales service is provided?

The packing list is: main unit *1, output line *2, power line *1, ground line *1 and short-circuit line *1. The instrument is repaired free of charge within one year of purchase for quality problems, and repair and technical service are provided for life.

Company Details

Bronze Gleitlager

,

Bronze Sleeve Bushings

 and 

Graphite Plugged Bushings

 from Quality China Factory
  • Business Type:

    Manufacturer

  • Year Established:

    2013

  • Total Annual:

    1000000-5000000

  • Employee Number:

    50~100

  • Ecer Certification:

    Verified Supplier

                        Xi'an Xu&Hui Electromechanical Technology Co., Ltd. /Xian XZH Electric Power Technology Co., Ltd. Has found in 2013, located in Xi'an, China. which is a highly experienced team dedicated to developing electrical...                         Xi'an Xu&Hui Electromechanical Technology Co., Ltd. /Xian XZH Electric Power Technology Co., Ltd. Has found in 2013, located in Xi'an, China. which is a highly experienced team dedicated to developing electrical...

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  • Xi'an Xu&Hui Electromechanical Technology Co., Ltd.
  • Building B8-01, Phase I, Ronghao Industrial City, No. 2098, Weiyang 9th Road, Gaoling District, Xi'an, China
  • https://www.xzhtest.com/

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