The cable fault tester can test various types of cables at the same time, such as short circuit, open circuit, high resistance flashover, high resistance leakage, etc. It can test cables with different voltages, different sections, different media and different materials. When measuring cable faults, the cable fault tester can test various types of cables at the same time, such as short circuit, open circuit, high resistance flashover, high resistance leakage, etc. It can test cables with different voltages, different sections, different media and different materials cable. When measuring cable faults, the cable can be thought of as an evenly distributed transmission line.
According to the theory of transmission lines (long wires), a pulsed voltage is applied to one end of the cable. The pulse is transmitted along the line at a certain speed. When the pulse encounters the fault point, it will reflect Distance Lx from fault point, Lx=V·T/2. To measure the full length, the terminal reflected pulse can be used: L=V·T/2 also knows the full length of the cable, and the pulse transmission speed can be measured: V=2L/T. The pulse method test is divided into low-voltage pulse method and high-voltage pulse method. The test principle of the two is the same, but the way of generating the pulse is different. The fault distance calculation of the intelligent tester is automatically completed by the instrument.
Secondary pulse method: The basic principle of the secondary pulse method is the pulse reflection method, which is a relatively cutting-edge new cable fault rough measurement method developed in recent years. Its technical characteristics are: the high resistance fault presents the waveform characteristics of the low voltage pulse short circuit fault, which is easy to interpret. In other words, at the moment when the high-resistance fault is broken down by the high-voltage pulse, the cable fault tester is used to transmit a low-voltage pulse signal to the faulty cable, and the low-voltage pulse short-circuit fault waveform is used to test the high-resistance fault of the cable.
Compared with the traditional test method, the advanced point of the secondary pulse method is that the complex waveform in the shock high-voltage flashover method is simplified to a simple low-voltage pulse short-circuit fault waveform. The key of the second pulse method is to add a high frequency and high voltage data processor to the flash tester. From the test principle, the test principle of the secondary pulse method has its advanced nature, but its test instrument is relatively complicated, and the use is also more complicated than the ordinary flash tester.
Connecting the emission source: what needs to be done here is to insert the red and black wiring plugs of the emission caliper A into the two terminals corresponding to the emission source. We can clip the launch caliper A on the identified cable, and the direction of the arrow is the cable terminal. Both ends of the identified cable should be grounded reliably.
At this time, you need to turn on the power switches of the transmitter and receiver and check the direction: on the identified cable two meters away from the transmitter caliper, use the receiver caliper B to clamp the cable, and the arrow above must point to the cable terminal. After that, we need to check the current flow and test the connection direction. At this time, note that the pointer of the ammeter of the receiver should be deflected to the right, and there are sound and light prompts.
After this, we need to remember the deflection direction of the receiving caliper head. Some of the above related introductions about the cable fault tester, I hope to be helpful to all friends.