DC system grounding fault locator

Product Details

The core problem of the HSZJD-8 DC system grounding fault locator in the current power system is the large on-site interference. When measured under different DC power sources and working conditions, the vast majority of products will make false positives and poor anti-interference performance. The reason why our product quickly established itself in this market is because it successfully solved the interference problem. The DC system grounding fault locator is developed and produced using sine signal phase advance processing technology and data transfer algorithm technology. This product falls between the two types of fixed and mobile, with a mobile usage method and online fixed performance. When searching for DC system grounding faults, there is no need to disconnect the power supply, and the grounding point can be located. The instrument can accurately detect the grounding resistance value of the DC system, providing a suitable and reliable high-precision detection instrument for the search and location of grounding faults in the power DC system.

DC system grounding is a fault that is prone to occur and poses a significant threat to the power system. Our company has independently developed and designed a portable DC grounding fault locator, which can be used to locate grounding faults in DC systems of any voltage level.

This instrument can quickly locate difficult faults such as indirect grounding, non-metallic grounding, loop grounding, positive and negative simultaneous grounding, positive and negative balanced grounding, and multi-point grounding in the DC system. It can also accurately display system voltage, ground voltage, and grounding resistance, truly solving the worries of operation and maintenance personnel.

Composition of instruments:

This instrument consists of three parts: a signal generator, a fault detector, and a signal collector (clamp meter). The signal generator is connected to the positive and negative busbars of the DC system and ground. When a ground fault occurs in the DC system, it will automatically generate a low-frequency small signal. The fault detector and clamp meter are independent of the signal generator, and are connected by a connecting wire. By collecting and analyzing the leakage current signal of the branch to be detected, the insulation condition of the branch can be determined.

HSZJD-8 DC System Grounding Fault Finder

The working principle of the instrument:

The working principle of the instrument is: when a grounding fault or insulation reduction occurs in the DC system (the insulation resistance of the entire DC system is less than the alarm setting value), and the DC system voltage monitoring instrument issues an alarm, the signal generator is connected between the positive and negative busbars of the DC system and the ground. The signal generator automatically judges the voltage level of the DC system, determines the polarity and grounding degree of the grounding fault, analyzes the insulation monitoring balance bridge circuit wiring method and balance bridge resistance size, forms intelligent feedback of signal output, and emits suitable low-frequency signals for system detection to the DC positive and negative busbars and ground, without affecting the system. It also displays the system voltage, positive ground voltage, negative ground voltage, and total impedance of the system to ground insulation in real time.

The fault detector detects the DC signal leakage current of each circuit to ground insulation, simulates and displays the insulation status of the grounding circuit, determines the grounding fault circuit (branch), and continues to detect the grounding fault along the fault circuit (branch), accurately locating the fault point.

The signal generator and fault detector both use microcomputer technology, which has the characteristics of high integration, fast judgment speed, high detection sensitivity, strong anti-interference ability, and accurate fault location. Fuzzy control theory and communication noise theory were utilized in software processing, and the algorithm was optimized based on the characteristics of the DC system. Even if the system is affected by large distributed capacitance interference, electromagnetic pulse interference, and other noise interference, it can accurately determine the grounding fault point, providing strong support for the search for grounding faults. Detecting sensors on hardware, the sensitivity of DC signal detection is as high as 0 1mA， The detection sensitivity can detect grounding between 150K and 500K, solving difficult problems such as multi-point grounding, loop grounding, and general insulation reduction.

Main Features

1) High precision sampling clamp table

This instrument adopts a high-resolution (0.1mA) signal sampling DC clamp meter, which can achieve the positioning of multi-point grounding and high resistance grounding points.

2) Grounding point direction display

This instrument has a grounding point direction display function, including three direction display modes: LCD screen display, indicator light indication, and voice prompt, which can efficiently and quickly process the positioning of grounding points in complex branches or loops.

3) Equipped with insulation index display function

The insulation index is introduced to analyze the insulation degree of the tested branch, which is reflected in the form of a number from 0 to 100. The larger the number, the worse the insulation. Combining this index with a high-precision clamp meter is very beneficial for detecting multi-point grounding and high resistance grounding.

4) Equipped with waveform display function

The so-called waveform display refers to the waveform of the signal generator searched by the detector during the detection process, which plays a very important role in finding the grounding process. Reasonable use of the waveform display in the detector can greatly improve the detection range and accuracy of the equipment to determine the accuracy.

5) Multi range conversion function

The instrument has a multi range conversion function, which can convert different ranges during the testing process, greatly improving the detection range and accuracy of the equipment to determine the accuracy.

6) Easy to operate, convenient to use, and fast

When in use, simply clamp the caliper on the branch to be tested, press the work button, and complete the detection of one branch in 3-6 seconds.

7) Signal generator and detector are not limited by distance

In complex DC systems, the signal generator access point may have a long distance from the ground search point, but the detector is not limited by this distance and can search at any point in the same system.

8) Safe and reliable operation

The signal generator needs to be connected to the DC system, which ensures the safety of the equipment. Based on the actual situation of the DC system on site, the signal generator can intelligently generate a signal current of 1.0-5.0mA with a high power of less than 0.2W. It is suitable for various DC systems and provides a guarantee for the safe and reliable operation of the DC system.

Main technical indicators

1) Range of detectable grounding resistance:

When the system voltage is 220V: 0-500K Ω

When the system voltage is 110V: 0-250K Ω

When the system voltage is 48V: 0-50K Ω

When the system voltage is 24V: 0-10K Ω

2) Detection signal power: ≤ 0.2W (output power of signal generator).

3) Resistance to ground distribution capacitance value:

The single branch capacitance to ground is ≤ 8uF, and the total capacitance to ground of the system is ≤ 100uF.

4) Applicable DC system voltage:

220V ± 10%, 110V ± 10%, 48V ± 10%, 24V ± 10%, or other voltage levels proposed by the user.

5) Environmental temperature:~35 ℃~+55 ℃.

6) Relative humidity: ≤ 95%.

7) Total weight: 3kg (signal generator, detector, accessories, aluminum alloy box).

8) Dimensions: 360mm x270mm x100mm.