NOYAFA Electronic specializing in testing instruments and cable testers for 16 years
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NOYAFA Electronic specializing in testing instruments and cable testers for 16 years
Author: Noyafa–CCTV Tester
Operation precautions of the cable fault tester during detection 1) First of all, it is necessary to list the possible causes of the fault and the basic conditions of the cable, such as whether it is a fault in operation or a fault in pre-test, whether it is a new cable or a cable with a long running time, Operation precautions of the cable fault tester when testing 1) First of all, it is necessary to list the possible causes of the fault and the basic conditions of the cable, such as whether it is a fault during operation or a pre-test, whether it is a new cable or a long running time. The cable, the approximate length of the cable, whether there is a connector in the middle of the cable, whether the cable has failed before, whether the cable is directly buried or laid in a cable trench, and the type of cable, etc. 2) Make sure that the cable is not tested before it is powered off. Both ends of the cable must be disconnected from other lines to ensure that the cable is powered off and the surrounding environment of the cable is in a safe state. 3) The tester must pay attention to the safety of operation. Before connecting the cable, connect each phase wire of the cable to the ground with a short-circuit wire for discharge. When discharging, one end of the short-circuit wire must be grounded first, and the other end of the cable must be connected to each phase wire of the cable for discharge.
For other electrical appliances, such as capacitors, test transformers, etc., it is necessary to discharge the electricity first and then connect the wires before wiring and removing the connecting wires. In short, to form an operating habit, do not be afraid of trouble, before each operation, pay attention to whether the electrical appliance is connected to the circuit, and discharge before operating. 4) During the test, first use the low-voltage pulse function of the flash tester to test the full length of each phase of the cable to see if the test waveforms are consistent when the three-phase armor is tested.
For most high-impedance faults, the test waveforms for each phase are consistent. For low-resistance faults and high-resistance faults with open-phase faults, the test waveform of the faulty phase is inconsistent with the full length of the tested cable, so that the fault distance can be directly tested with low-voltage pulses. 5) When using the high-voltage flashover method to test, no matter whether the cable fault is a high-resistance fault or a low-resistance fault, the high-voltage flashover method can be used for testing.
For low-resistance or disconnection faults that can directly test the fault distance with low-voltage pulses, generally high-voltage flashovers are also used for verification testing and accurate determination of the fault point. When testing the high-voltage flashover method, it should be noted that no matter whether the cable has a single-phase fault or a multi-phase fault, when testing a faulty phase, the other cable phase wires should be short-circuited with the cable armor to reduce the interference of other cables and improve the performance of the cable. Test accuracy. 6) After the high-voltage flashover method test is completed, the fault distance is determined, and the fault can be accurately determined.
When using the acousto-magnetic synchronous locator, fault locating and path detection can be carried out synchronously.
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