Don’t look at me to perform the said test. I cannot find my meter. It is well known that I need to go and buy a screwdriver or whatever every time I need one. Much easier and more cost-effective than to spend hours looking for one.
The plug is of the new type, therefore the switch may be a double pole and it will isolate the neutral and live. All old plugs were single pole with the 220V potential neutral to the plug point. There is no way my colleagues and I were doing it wrong all these years.
Also, your pics show the black lead on one point only. Try the other point and see. Double pole will find it dead too. Single pole will give 220V.
But you have raised a very interesting point and I will be measuring some plugs in my 70 year old home with old style plugs tomorrow. I’ll let you know how it goes. I will measure in the distribution board as well to confirm my readings. The neutral is connected to a bar there.
Have a nice evening.
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:
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, VNE = 220V & VLE = 0V & VNL = 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 VNE = 220V and VLE = 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 VNL = 0V.
Similarly, in case 2 (switch on, VNE = 220V & VLE = 220V & VNL = 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 VNE = 220V and VLE = 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 VNL is either 0V or 440V, which again contradicts the claim that VNL = 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
Sorry Mefi I’ve been a bit swamped. Tonight pinky promise.
So, I did do this, multimeter set to measure <500V AC:
Switch off:
VNL = 0V
VEL = 0V
VNE = 0V
Switch on:
VNL = 220V
VEL = 220V
VNE = 0V
Thanks, BM, much appreciated. So, bottom line is that your readings agree with ours.
'Luthon64
But … then surely no current would flow once the live wire is opened.(The potential difference between the live and neutral - each sitting at 220V relative to the ground if I read the statement correctly - would be zero or close to it.) This too little too late, of course, since the empiricists have already done their thing.
Bear in mind that we’re dealing with AC so the above would only be true if live and neutral are perfectly in phase (assuming that both are at a potential of 220V RMS above ground). For comparison, with three-phase power where the phases are shifted by 120° from one another (3×120° = 360°), the RMS potential between any phase and ground is 220V, whereas it’s 380V between any two of the phases. (It’s no coincidence that 380 ≈ 220×√3.)
'Luthon64
True … the buckets must move up and down together.