The method to determine the fault type of customized Wire and Cable from China is to measure the insulation resistance of each phase at one end of the line with an insulation resistance meter. Generally, the fault is determined according to the following conditions.

When the insulation resistance of one or several cores of customized Wire and Cable from China to the ground is measured by telemetry, or the insulation resistance between cores is less than 100 kohm, it is a low resistance grounding or short circuit fault. When the insulation resistance of one or several cores of the customized Wire and Cable from China to the ground is measured by telemetry, or the insulation resistance between cores is much lower than the normal value, but higher than 100 kohm, it is a high resistance grounding fault. When the insulation resistance of one or several cores of the telemetry cable to the ground is high or normal, a conductor continuity test shall be conducted to check whether there is a wire break. If there is a wire break fault. When one or several conductors of the telemetry wire and cable are discontinuous and grounded through resistance, it is a broken wire and grounding fault.

The flashover faults of customized Wire and Cable from China often occur in the preventive voltage withstand test, and most of them occur at the wire and cable terminals and intermediate joints. Flashover sometimes occurs several times in a row, with an interval of several seconds to several minutes. When the resistance at the fault point is equal to infinity, it is easy to find the open circuit fault by measuring with the low-voltage pulse method. In general, pure open circuit fault is rarely seen. Generally, the open circuit fault is the phase to ground or phase to phase high resistance fault, and the phase to ground or phase to phase low resistance fault coexists. When the resistance at the fault point is equal to zero, it is easy to find the short-circuit fault measured by low-voltage pulse method, but this fault is rarely encountered in practical work. When the resistance at the fault point is greater than zero and less than 100 kohm, it is easy to find the low resistance fault by measuring with the low-voltage pulse method.

The customized Wire and Cable from China flashover fault can be measured by direct flashover method. This fault usually exists in the connector. The resistance at the fault point is greater than 100 kohm, but the value changes greatly, and each measurement is uncertain. High resistance fault can be measured by impulse flashover method. The resistance at the fault point is greater than 100 kohm and the value is determined. Generally, when the test current is greater than 15mA, the test waveforms are repeatable and can be overlapped, and one waveform has one emission, three reflections, and the pulse amplitude is gradually weakened, the measured distance is the distance from the fault point to the cable test end; Otherwise, it is the distance from the fault point to the opposite end of the customized Wire and Cable from China test. The fault point can be found directly for processing, which improves the efficiency of fault detection.