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This post was last edited by Yu Qin on 2020-6-9 21:14. Cable fault testing instruments are designed for power cable engineers and cable workers to address issues related to cable identification techniques. Users can use the instrument to accurately identify one specific cable among multiple cables, thereby preventing serious accidents caused by accidentally pulling on a live cable. Cable identification begins with operations at both ends of the cable, and it is essential that the numbers at these ends are correct. This product is intended solely for identifying severed cables on-site; it is strictly prohibited to connect the cable identifier to active power cables. The instrument consists of a transmitter, a receiver, and a flexible current clamp. Methods for locating cable fault points: 1. The so-called sound measurement method – this method involves detecting sounds resulting from the discharge in the faulty cable. This invention is effective against flashover and discharge of the insulation layer due to the high-voltage cable core. The equipment used in this method is a DC withstand voltage tester; safety must be taken into account when using this method, with dedicated personnel assigned to monitor the ends of the testing equipment as well as those of the cables. 2. The bridge method involves using a two-arm bridge to measure the DC resistance of the cable cores, and then accurately determining the actual length of the cable. The fault location is calculated based on the direct proportionality between cable length and resistance. The advantages of this method are as follows: when there is a direct short circuit in the cable cores or when the contact resistance at the short-circuit point is less than 1Ω, the error in determination is generally no more than 3 meters. If the contact resistance at the fault location is greater than 1Ω, the voltage is increased to reduce the resistance to below 1 ohm, after which further measurements are carried out using this method. 3. During the operation of cables using the capacitive current measurement method, there is capacitance between the cable cores and between the cores and ground. The capacitance is evenly distributed, and it is linearly related to the cable length. The capacitive current measurement method is based on this principle, and it provides very accurate detection of cable core break faults. 4. Zero potential method, namely potential comparison method. It is suitable for grounding faults in cable conductors of shorter length; this method is simple to use, requiring no precision instruments or complex calculations.