The high-voltage bridge cable fault locator utilizes the MURRAY bridge principle to accurately locate breakdown points and low-insulation-resistance defect points in wires and cables post-laying, and it is also effective for identifying defect points in cable manufacturing facilities. The equipment employs a switching power supply to generate a high-voltage constant current source, characterized by a no-load voltage of 15KV and a short-circuit current of 50mA. A high-sensitivity amplifier and galvanometer provide precise balance indication, while a proportional potentiometer forms the balance bridge. The entire system is placed at a high potential, with a specially designed double-core high-voltage rubber measurement cable that utilizes the four-terminal resistance measurement method to mitigate errors caused by lead resistance. The cable’s braided shielding layer ensures reliable grounding. For operational safety, the control panel’s operation button is situated at a low potential, and the bridge is manipulated using an insulating rod. The high-voltage constant current source and bridge are housed in a portable aluminum alloy case, which ensures the device’s high voltage, light weight, convenient operation, and safe use. When compared to the wave reflection method, the bridge balance method is devoid of blind areas and is particularly advantageous for pinpointing breakdown points in short cables and near cable terminations, with the added benefit of easy operation.
No load voltage | ≤15KV |
Short circuit current | ≤100mA |
Positioning accuracy | ±(0.1%·L±1)M |
Weight | 16 kg |
Power supply | AC 220 and 9V battery |