The device can not detect wires but unfortunately the electricity. This can be tested very easily: you put an extension cord straight at floor, plug it into an outlet and possibly at the other end to something. The device can be seen barely able, directly above the cable selbiges! The same situation also in pipes in the wall. I had, for example an old supply line for an electric stove (three-phase). While hanging off no stove, but the lines were (measured) energized. They were just recognized right at the end, to the can on the lines weak. The line then went into a tube, which was about 4 cm under plaster. No recognition, at best, random beeping, ambiguous. The further course of the line could not be found. Conclusion: my copy is unusable for this application!
It's me then but managed to achieve with the device something: When set to 'Metal Search' I could (whether on the network or not the network), see the lines very well, since it is, after all, is 5 times 2.5 copper lines. However, it worked with other pipes with fewer and thinner cables also significantly less well.
It is quite obvious that equipment of this type, the purely passive recognize (50 Hz radiation from the cable, which naturally is extremely weak but) not just really work. I do not understand Bosch - they spoil themselves with such devices only reputation. The unit is robust and clearly superior to the various low-detectors, but simply prefer not fulfilled an important function. It may be that in massive current-removal detection is better - but who can do that? A lamp on the cable (see above) is not enough. You can not pin anywhere a heater well, if you take a look for a line, especially if you do not know the wiring just yes.
Because you can absolutely not rely on the current detection, I recommend to use the device only to metal-locating. Pipes (I have not even tried) should also recognize quite well. It is therefore suitable for protecting against drilling conditionally.
Therefore the devaluation: The device really met only partially, what was promised. As such, it is in spite of robust design really too expensive and you should not quite sure call 'professional'. The location does not seem to be working well only with mains voltage on the line. One should really not expect ...
I have now found devices that feed into the grid (where it does not matter whether the line or not depends on the network). These devices feed a higher frequencies, which can then be also places. Although they cost more, but so that you can then work professionally (in some modes can such a device up to 2 meters places!). So if you really want to seek and find lines, this unit should rather not take you.