The working principle of the cable fault tester is mainly based on the radar ranging principle, which detects and locates the fault point in the cable by transmitting pulse signals and receiving their reflected waves. The following is a detailed work process:
1. Overview of Working Principle
The cable fault tester emits a pulse signal to the cable through the testing end. When this pulse signal propagates in the cable, if it encounters a location with mismatched characteristic impedance (such as a fault point), a reflected wave will be generated. The instrument will simultaneously collect the incident waveform and the reflected waveform, and display them on the screen. By analyzing and comparing these two waveforms, the distance from the fault point to the testing end can be calculated.
2. Specific work steps
① Transmitting pulse signals:
The tester emits a pulse signal to the cable at the testing end. This signal can be a low voltage pulse or a high voltage pulse, depending on the testing method and the type of cable fault.
② Receive reflected waves:
When the pulse signal propagates in the cable, if it encounters a fault point or an impedance uneven point, it will generate a reflected wave. The tester will receive this reflected wave and display it on the screen together with the incident waveform.
③ Waveform analysis:
By using a dual electronic cursor to capture the two characteristic inflection points of the waveform, the time T required for the radio wave to propagate back and forth in the cable can be measured. This time T, together with the propagation speed V of the radio wave in the cable, is used to calculate the distance S from the fault point to the testing end. The calculation formula is: S = VT / 2。
④ Fault location:
Based on the calculated distance S, the approximate location of the fault point on the cable can be determined. In order to more accurately locate the fault point, other testing methods such as acoustic measurement and acoustic magnetic synchronization can also be combined.
3. Testing method
The cable fault tester supports multiple testing methods to adapt to different types of cable faults. Common testing methods include:
① Low voltage pulse method:
Suitable for precise distance measurement of low resistance, short circuit, and wire breakage faults. By applying a low-voltage pulse signal to the cable and observing the reflected waveform, the fault point can be located.
② High voltage flashover method:
Suitable for distance measurement of high resistance and flashover faults. By applying high-voltage pulse signals to the cable, the fault point is flashover discharged, and the discharge waveform is observed to locate the fault point.
③ Acoustic measurement method:
Mainly through the discharge of high-voltage pulse generators, sound and seismic waves are generated at the fault point, and the signals are received and amplified by acoustic probes for fixed-point detection. This method is simple and effective, suitable for precise positioning of various cable faults.
④ Acoustic magnetic synchronization method:
By combining the characteristics of acoustic measurement and electromagnetic wave method, higher precision fault location can be achieved through acoustic magnetic synchronous fixed-point instrument. This method uses a discharge pulse magnetic field as a synchronization signal to digitally sample and display the waveform of the sound, thereby more accurately determining the location of the fault point.
In summary, the cable fault tester detects and locates fault points in cables through steps such as transmitting pulse signals, receiving reflected waves, waveform analysis, and fault location. Its working principle is based on radar ranging principle and combines multiple testing methods to improve the accuracy and efficiency of detection.
The ZC-700A cable fault tester can be used to detect low resistance, high resistance, short circuit, open circuit, leakage faults, and flashover faults of various cables. It can accurately detect the fault point location, cable length, and cable burial path of underground cables. It has the characteristics of accurate testing, high level of intelligence, wide adaptability, stable performance, and lightweight portability. The instrument adopts a Chinese character system, high-definition display, and user-friendly interface.
Cable tracing and fault location are composed of a pathfinder, a locator, a T-probe, an A-frame, an earpiece, etc. This instrument is a specialized instrument for cable fault location testing, suitable for testing various cables with metal conductors (wire pairs, protective layers, shielding layers). Its main functions are to locate and test points of poor ground insulation, detect cable paths, and test cable burial depth.
Kvtester Electronics Technology Co.,Ltd. is a high-tech enterprise specializing in power testing, testing, research and development, production, and sales of testing equipment. It has been engaged in the electrical testing industry for many years, and its products are of high quality. We welcome customers to come and purchase. Service hotline: 0086-27-81778799, to learn more, visit the official website: www.kvtester.com
