What are the operating techniques for Cable Fault Locator?

1. After the cable fault tester has connected the lines on site according to the multiple pulse method, it is normal if a more ideal test waveform cannot be obtained by applying high impact voltage at one time. Because the distance to the fault is not known in advance, the electrical strength of the fault point is also unclear. If the impulse voltage is not high enough and the fault point is not broken down by the impulse high voltage to generate an arc, the fault echo cannot be collected. At this time, only the terminal open circuit waveform can be seen. The impulse voltage must be increased until fault echoes are seen.

2. Sometimes the fault point is far away from the test terminal and the echo is weak, so the "length selection" must be adjusted to obtain a stronger fault echo. The cable fault tester has three states: "short distance", "medium distance" and "long distance". "Short distance" is suitable for testing faults within a distance of 1km, "medium distance" is suitable for testing faults within a distance of 1~3km, and "long distance" is suitable for testing faults within a distance of 3~16km.

3. In order to ensure sufficient breakdown of the fault point and sufficient arc duration, it is recommended to use 2μF energy storage capacitors with a withstand voltage of 35kV or above.

4. During the multiple pulse method test, there is a "pulse generator" in series between the high-voltage equipment and the faulty cable. The actual impact high voltage applied to the faulty phase of the cable is lower than the voltage output by the high-voltage generator. If the output voltage of the high-voltage generator has reached 35~42kV and the fault point has not yet broken down, the impact high-voltage flashover current sampling method should be replaced for testing.

Weshine Electric Manufacturing Co., Ltd.