It’s a single-pole switch, operating only the
L connection. Would you like a photo of the disassembled wall socket?
As I wrote before, the other four readings were in line with what was expected, so we didn’t bother taking any photos of those measurements. This means that with the switch in the “on” position, we measured 220V between
N and
L, and 220V between
E and
L. With the switch in the “off” position, we measured less than 1V between
N and
L, as well as between
E and
L.
From BM’s Wikipedia link:
Ground or earth in a mains (AC power) electrical wiring system is a conductor that provides a low-impedance path to the earth to prevent hazardous voltages from appearing on equipment (high voltage spikes). (The terms "ground" and "earth" are used synonymously here. "Ground" is more common in North American English, and "earth" is more common in British English.) Under normal conditions, a grounding conductor does not carry current. Grounding is an integral path for home wiring also because it causes circuit breakers to trip more quickly (ie, GFI), which is safer. Adding new grounds requires a qualified electrician with information particular to a power company distribution region.
Neutral is a circuit conductor that normally carries current back to the source. Neutral is usually connected to ground (earth) at the main electrical panel, street drop, or meter, and also at the final step-down transformer of the supply. That is for simple single panel installations, for multiple panels the situation is more complex.
(Emphasis added.)
The underlined bit means that an AC voltage of 220V between
E and
N will short-circuit at the point where
E and
N are connected to one another.
What’s more, as an exercise in pure logic, the six measurements claimed simply can’t be true.
Case 1 (switch off, V
NE = 220V & V
LE = 0V & V
NL = 0V) implies that at least one of
N,
E or
L’s potential depends on which pair is being measured. For example, if we accept that V
NE = 220V and V
LE = 0V are both true, then
L and
E must be at the same potential with
N at a potential of +220V or –220V; however, this logical necessity contradicts the claim that V
NL = 0V.
Similarly, in case 2 (switch on, V
NE = 220V & V
LE = 220V & V
NL = 220V) implies that at least one of
N,
E or
L’s potential depends on which pair you’re measuring. For example, if we accept that V
NE = 220V and V
LE = 220V are both true, then
N and
L must either be at the same potential, or one of them is at +220V while the other is at –220V (i.e., they’re phase shifted by 180°). In turn, it follows necessarily that V
NL is either 0V or 440V, which again contradicts the claim that V
NL = 220V.
All of that said, I still await BM’s results with keen interest. If I’m wrong, I will most seriously and urgently have to revisit my understanding of household AC electricity supply.
'Luthon64
