Based on the MURRAY bridge principle, the high-voltage bridge cable fault locator is specifically designed to identify breakdown points in various laid wires and cables, as well as defect points with low insulation resistance, even those that have not broken down. It is also applicable in cable factories to locate cable defects. The device incorporates a switching power supply to create a high-voltage constant current source, with a no-load voltage of 15KV and a short-circuit current of 50mA. A high-sensitivity amplifier and galvanometer are used for balance indication, while a proportional potentiometer forms the balance bridge. The entire assembly operates at a high potential, and the measurement cable is a specially designed double-core high-voltage rubber cable that uses the four-terminal resistance measurement method to eliminate errors from lead resistance. The cable is reliably grounded through its braided shielding layer. For safety, the operation button on the panel is at a low potential, and the bridge is operated using an insulating rod. The high-voltage constant current source and bridge are integrated into a portable aluminum alloy case, making the device lightweight, easy to operate, and safe to use. Compared to the wave reflection method, the bridge balance method has no blind area and is particularly suitable for detecting breakdown points in short cables and near the cable ends, with 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 |