High-Voltage Cable Outer Sheath Fault Testing System

The MOEORW-WLW91 system consists of a cable outer sheath fault test power supply and a step voltage locator. It is engineered for pre-location and precise pinpointing of faults on outer sheaths of high-voltage cables. This device can detect grounding faults and excessive leakage current on single-core and three-core high & extra-high voltage cables, and conduct DC withstand voltage tests on outer sheaths made of HDPE and PVC materials. It serves as essential professional equipment for cable maintenance teams, power transmission and transformation engineering companies engaged in high-voltage cable operation and project construction.

The fault detection process is divided into two stages: rough measurement and precise positioning. Rough measurement adopts voltage drop method and bridge method to estimate fault distance, while step voltage method is applied for accurate fault pinpointing on site.

1. Rough Measurement
Two mainstream methods are adopted for preliminary ranging of extra-high voltage cable outer sheath grounding faults. The bridge method features high accuracy and simple operation, yet it cannot identify multi-point grounding faults or faults on chain grounding connections of three-phase cables. The voltage drop method effectively compensates for the above limitations and is applicable to more complex fault conditions.
 

2. Precise Positioning
The step voltage method is utilized for accurate fault location. The test current flows into the earth at the fault point and forms a distributed potential field. When moving two ground probes near the fault point, the step voltage value rises when approaching the fault, decreases and reverses polarity after passing the fault. The position where the display shows zero reading is the exact location of the grounding fault.

1. MOEORW-WLW91 Cable Outer Sheath Fault Test Power Supply

2.MOEORW-WLW91 Step Voltage Locator

Cable Outer Sheath Fault Test Power Supply

• Hardware & Operation: Equipped with a 4.3-inch color touch LCD and touch buttons. The intelligent human-machine interface simplifies operation procedures for field staff.
• Multi-mode Operation: Supports three independent working modes to meet fault ranging, positioning signal output and DC withstand voltage test requirements in different scenarios.
• Safety Protection: Adopts combined software algorithm and hardware circuit design, equipped with over-current and over-voltage protection functions to ensure operational safety under various working conditions.
• Signal Output: Stably outputs high-voltage pulse signals to match the step voltage locator for subsequent precise fault positioning.
   

Step Voltage Locator

• Structural Design: Portable compact structure with light weight, easy to carry and deploy in complex field environments.
• Display & Control: Built-in color LCD and soft keys, with analog pointer display for signal polarity to deliver intuitive data presentation.
• Detection Performance: High sensitivity and wide response range, capable of capturing weak voltage signals generated by cable sheath faults.
• Power System: Integrated large-capacity rechargeable battery, ensuring long-duration continuous operation for large-scale line inspection work.

1.Rough distance measurement of outer sheath faults on laid high-voltage cables.
2.Accurate on-site positioning of high-voltage cable outer sheath fault points.
3.DC withstand voltage test for outer sheaths of extra-high voltage cables.
4.Fault ranging for main insulation of cables of all voltage classes.
5.Fault location for direct-buried cables below 10 kV.
6.Fault detection for underground cables and all-plastic cables without metal sheaths.

1.MOEORW-WLW91 Cable Outer Sheath Fault Test Power Supply × 1
2.MOEORW-WLW91 Step Voltage Locator × 1
3.Ground probe rod × 2
4.Connecting cables and accessories × 1 set
5.Operation manual × 1