Short-circuiting detection / locating electrical interferences
With the aid of a power failure assessment, CP-shutdowns with third objects can be detected. An example is low/middle-voltage cables that make contact with the protected pipeline via its steel outer casing, causing the CP-protective current to flow away. A CP-breakdown with another cable is very inconvenient, especially because it undermines the optimum functioning of the rectifier installation by considerably reducing its capacity (depending upon the size of the interference).
By using a transmitter to place a signal with a certain frequency on the pipeline, the CP-interference can be localised above-ground and followed with the aid of a receiver. If the signal quickly lowers in strength, or if it deviates from the exact location of the pipe as indicated on the underground area drawing, there may be a CP-disturbance at this location.
The next step is then to excavate the detected location for a visual inspection. If a CP-breakdown is actually found, the disturbance has to be fixed by electrically separating the pipe and the third object(s), for example by using PE-strips.