Allow me to summarize the DC injection hypothesis: - It is theoretically possible to add DC to provide ~3kW of power that would be invisible to the PCE-830.
However: - Given the size of the wires, I guess that amperage would need to be below 50 A. Otherwise the wires would heat up too much and this would show on the thermal camera. - This means that a DC offset of >60 V is required for 3kW injection. - This means that the scammer must be confident that any instrument or device connected would tolerate a >60V DC offset. This is a large offset. As the DC resistance of the primary winding of transformers is small compared to their reactance at 50 Hz, the extra DC would probably destroy any attached transformers. - The use of any electrical instrument capable of detecting DC would need to be prohibited. A 5$ multimeter can detect DC. So do oscilloscopes, or Fluke power analyzers. These would have to be prohibited. - Any significant DC current will produce a significant DC magnetic field nearby. Such a field is easily detectable by most recent smartphones or a simple compass. - Temporarily switching the extra DC power off when DC-capable instrumentation is used wouldn't be possible, as the temperature would drop rapidly and this would immediately show on the IR video / temp curve. -- Berke Durak
