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–Noyafa Cable Tester
Common sense of cable fault detection 1. How to identify the type of cable fault when testing faults using the cable fault tester? Answer: Correctly judging the type of cable fault is the first step in finding faults. The required instruments are a high resistance meter (shaking meter) and a multimeter. Tips for cable fault detection 1. How to identify cable faults when testing faults with a cable fault tester type? A: Correctly judging the type of cable fault is the first step to find the fault. The required instruments are a high resistance meter (shake meter) and a multimeter. The specific steps are divided into two steps: the first step: measure the relative-to-ground insulation resistance and the phase-to-phase insulation resistance, and identify the faulty phase of the cable; the second step: check whether the cable conductor is broken. (1) When measuring the relative-to-ground insulation resistance and the phase-to-phase insulation resistance, first use a high resistance meter (shake meter) to measure the insulation resistance between A to ground, B to ground, C to ground, AB, BC, and CA respectively, and find out Phases with unacceptable insulation resistance values.
If the measured value of the high resistance meter (shake meter) is 0M ohm, then use the multimeter to retest. (2) Conduct a conductor continuity test to check whether the cable conductors are disconnected, first short-circuit and suspend the three-phase conductors at the far end, and measure the loop resistance of the interphase conductors with a multimeter at the near end. If they are all zero ohms, there is no wire. Core disconnection fault; if the value is zero, there is a disconnection fault at the same time. 2. What is the procedure for cable fault detection and location? Answer: In order to quickly and accurately find the cable fault, it is necessary to follow the scientific fault detection and location procedure: Step 1: Determine the nature of the cable fault; this step requires a high resistance meter and a multimeter.
The second step: pre-positioning; roughly measure the distance of the fault point of the cable. This step requires a high-voltage bridge, a pulse reflector or a high-voltage wave reflection method. The third step: cable path positioning; to detect the unclear cable path, this step requires a pipeline locator. Step 4: Accurately determine the point; according to the pre-positioning results, combined with the cable path, accurately determine the location of the cable fault point, and finally obtain the specific location of the fault point, with an allowable error of 0.1 meters.
This step requires an acousto-magnetic time-difference method, a step-voltage method, or a minimum-twist method to precisely locate the instrument. 3. Classification of cable faults? Answer: According to the first step of the procedure of cable fault location - judging the nature of the cable fault, it can be divided into cable main insulation fault and cable outer sheath fault according to the location of the cable. On the basis of the main insulation fault of the cable, it is further divided into: low-resistance grounding fault, low-resistance short-circuit fault, disconnection fault, high-resistance grounding fault, high-resistance short-circuit fault, flashover fault, leakage fault, intermittent fault, etc. .
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