"Artemis" wrote...
Stan wrote:

Question: The wires within the wall were alive; but you could not get any
indication; right?
Was the test tried when there was current 'flowing through the wires' to
some appliance/device etc. plugged in further down the circuit?
Reason I ask is because I have once or twice been able to detect certain
wiring location (using something that draws quite a few amps, such as a
hair dryer/heat gun etc. = 12amps. 2 115 volts) not something lightweight
(such as 40 watt lamp bulb = 0.3 amps) using a small powerful hand held
magnet and feeling the vibration caused by the significant amount of AC
current flowing through the wires!
In some cases it seemed that even though the two wires carrying current,
hot and neutral, are very close together and their respective magnetic
fields will thereby tend to cancel, there is enough difference between
them to detect in certain cases.

You must be wearing your tinfoil hat for this method to be effective.

Nope, the hat doesn't matter, as it's a method that will work even through
the tinfoil. The foil would block the electrostatic field from the cabling
(which would be negligible for 220V 2-phase power, anyway), but the
electromagnetic field from the long narrow single-turn solenoid (the two
phases or the phase/neutral pair) will pass through the foil (whether a hat
or plasterboard backing) just fine - with a strong enough magnet, you'd be
able to feel the vibrations alright, a search coil would be even better.

Dave H.
(The engineer formerly known as Homeless)