Product Details

Cross-linked Cable Outer Sheath Fault Tester

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Cross-linked Cable Outer Sheath Fault Tester is mainly used for withstand voltage test of cross-linked cable outer sheath, and can also be used to accurately pinpoint outer sheath faults of single-core cables, accurately pinpoint ground leakage faults in low-voltage cables, and pre-locate outer sheath faults of high-voltage cables.

Basic Information

Cross-linked Cable Outer Sheath Fault Tester is mainly used for withstand voltage test of cross-linked cable outer sheath, and can also be used to accurately pinpoint outer sheath faults of single-core cables, accurately pinpoint ground leakage faults in low-voltage cables, and pre-locate outer sheath faults of high-voltage cables. The output voltage of the cable outer sheath tester is 10KV and below, fully meeting the cable outer sheath withstand voltage test regulations of the Chinese national standard GB50150-2006, including cable outer sheath acceptance tests and preventive tests suitable for cross-bonding systems, as well as fault location of cable outer sheaths. Quickly and accurately find ground faults and leakage current anomalies in 10kv-500kv single-core and three-core high-voltage and ultra-high-voltage cable outer sheaths. At the same time, it can perform 5kv-10kv, 1-minute DC withstand voltage tests on HDPE and PVC cable outer sheaths. It is an essential special instrument for cable equipment maintenance of 10kv-500kv single-core and three-core high-voltage and ultra-high-voltage cable operating units, ultra-high-voltage cable engineering companies, and various power transmission and transformation engineering companies.

With the full-scale implementation of urban network transformation, many power supply bureaus, construction parties, and even design units are encountering 110kV XLPE cables for the first time. Due to time constraints and lack of experience, many cables fail the outer sheath withstand voltage test (10kV/1min) after laying. Currently, most outer sheaths use HDPE material, which has passed a DC 25kV/5min withstand voltage test in the factory with leakage current as low as tens of μA. Therefore, defects after laying are mostly caused by external damage during laying, including backfilling and cover plate installation. Defects after operation are usually caused by termite bites, water ingress in grounding boxes, deterioration of existing defect points, moisture penetration at the bifurcation of grounding wires causing insulation resistance drop, etc. Sometimes, due to deep burial or complex surrounding conditions, locating the defect is very difficult, and some defect points remain unresolved for years, leaving hidden dangers for operation.

110kV and above power cables are all single-core cables. The sheath of single-core cables is an important part of the cable. The quality of its insulation directly affects the service life of the cable and the safe and reliable operation of the power grid. The reasons are as follows:

a. Sheath damage leads to multiple grounding points of the cable metal shield, causing circulating currents in the metal shield, resulting in losses and heating, leading to local overheating of the insulation and accelerating insulation aging, seriously affecting the main insulation life.

b. Insulation damage of the sheath leads to moisture ingress, increasing the probability of water tree aging in the main insulation, seriously affecting cable life.

c. The main insulation experiences electric field concentration at corroded areas of the metal sheath, easily causing partial discharge and triggering electrical trees, threatening the short-term safe operation of the cable.

With the increase in the use of XLPE cables and the rising voltage levels year by year, some cable laying environments are extremely harsh. Coupled with large-scale infrastructure excavation causing cable damage, the actual damage to cable insulation sheaths is very common and must be taken seriously. The insulation status of cables and outer sheaths should be monitored in a timely manner, and damaged sheath areas should be located and repaired to ensure the safe operation of the urban underground power grid.

110kV and above high-voltage cables have insulation requirements for their non-metallic outer sheaths. IEC standards require that the outer sheath of 110kV cables withstand 10kV for one minute during commissioning tests. If the outer sheath of high-voltage cables is damaged, it will cause multiple grounding points of the metal sheath during operation, resulting in circulating current losses and affecting the safe operation of the cable. Therefore, it is necessary to detect and handle cable outer sheath faults.

Cross-linked Cable Outer Sheath Fault Tester can perform the following tests: pre-location of sheath faults on medium and high-voltage shielded cables, pre-location of ground faults on low-voltage cables with plastic insulation, and accurate pinpointing of cable faults using the step voltage method.

Due to the excellent conversion effect achieved by full-wave rectification, this device is very suitable for converting high-resistance cable faults in low-voltage power cables into low-resistance faults.

Features of the new sheath detector:

Continuously adjustable output voltage, voltage range: 2000V, 4000V, 6000V, and 10000V;

Overload protection through voltage and current control;

Low-power fault location to avoid damaging adjacent lines or cables;

Voltage and current display via analog meter;

Automatic discharge device provides functions for clearing residual charge and grounding the test object;

Good high-resistance fault conversion effect through full-wave rectification;

Main Functions

(1) A powerful supplement to the reflection method, providing more accurate preliminary measurement results and high reliability.

(2) An effective means to solve faults in PVC cables with poor wave propagation characteristics and low-voltage cables without copper shielding.

(3) Test voltage is subdivided into three levels: 2000V, 4000V, and 10000V, suitable for cables of different voltage levels.

(4) No blind spots in the measurement range.

(5) Automatic discharge function of the instrument after voltage drops to zero.

(6) Suitable for pre-location of faults in 380V-220kV high, medium, and low-voltage power cables.

(7) Suitable for accurate pinpointing of 380-1000V cables using the step voltage method.

(8) Suitable for pre-location and accurate pinpointing of outer sheath faults in 66kV-220kV cables.

(9) The WHT-08 high-voltage generator is also a cable fault converter, capable of converting difficult high-resistance faults up to 500 megohms into low-resistance faults.

Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.