Domestic wiring: is a power socket using power when "On"?

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Fata.... Look, when the switch is on, [compared to when it is off] there is about another 3 centimeters of conductor connected to the end of the incoming supply. There is no power at all being used, and anyone that asserts there is is plainly a lunatic that has no idea what they are talking about. That stuff you quoted above and the drawings area all a load of complete rubbish.

Again, tell the idiot to come on here and explain his ideas... We need a laugh... [What do they do for a job by the way?? What are their qualifications?? That should be good for a laugh...]

john..

 
Hello.

In a domestic UK home, 240V, if I have the socket switch in the "On" position, is it drawing current and thus costing me money even though nothing is plugged into the socket?

If I recall some physics, is this to do with transformers or am I off-track?

Thanks in anticipation.


If you recall basic physics, electricity requires a circuit path in order to flow..

[Supply] -> [Cable] -> [Maybe control switch] -> [Cable] -> [Load] -> [Cable] -> [Back to supply]

I have added a simple sketch of a typical single socket with a built in switch...

Try to follow a path from supply down the Live then some how back to the supply via Neutral...   while the internal switch is "OFF" (open)

The dotted lines show where a typical appliance (load) path could flow..

IF the switch was "ON" (Closed).

socket switch.jpg

Your guy is talking tosh and is a blithering idiot when it comes to electricity...

Do not take any advice off him about electrical issues....

(he may be a good gardener or cook or painter etc.. etc..

But knows nothing about how standard UK socket outlets work)

Guinness

 
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I emailed that post from yesterday (with the 3x diagrams) over to "him", this was this morning's reply as I believe he may have taken the time to read the post and the Comments below that post.

"Interesting yes - but its not science.

Everyone is entitled to their own opinion but not their own facts.

If there is a voltage in a closed circuit (one that is switched on) there will be a current.

Where there is a current there is power

W = A x V

That's science - sorry - don't care about opinion, its not evidence, Andy."

 
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Childish answer Andy - I am looking for a far more educated and insightful comment / set of comments, to this post, just childishly slagging a.n.other off suggests you have little constructive wisdom to contribute, as some here have taken their time so to do; as illustrated in some actually explaining why and how this in incorrect or intact correct. 

Can I ask you to bow out now and not continue this thread, thanks in anticipation as I gain nothing from your insight?

 
if its switched off then there is an extremely high resistance (basically, infinity). so with basic ohms law there will be no current flowing, so no power used. very basic concept that if you (and your imaginary friend) cannot understand, then leave well alone

 
Play nice children.

There can be no current flow through a domestic distribution circuit from a socket outlet unless there is a load connected, and, unless there is something plugged in, then there is no load connected, ergo, no current flow.

(From a real registered professional engineer)

Your current advisor is either misunderstanding the scenario, or, there is a mix up in questions somewhere along the lines.

The fact is that regardless of whether the switch on the socket outlet in the picture you posted earlier to which I quoted & replied, there can be no current flow as there is no current path between the outlet pins of the socket.

In fact, going from memory looking at that MK socket, it is double pole switched, and, thus isolates both live conductors in the socket when switched off, when switched on, it will allow current to flow, when a load is plugged in.

IF, the switch shorted out the supply as in the hand drawn diagrams you posted then the circuit protective device would operate every time the switch was closed with no plug inserted.

Also, the "box of tricks" drawn into the supply line does not exist in a distribution circuit.

If one is talking about connected appliances such as a phone charger, or TV, laptop power supply etc, then that is a different story.

These contain switched mode power supplies, passive and perhaps active components, which have parasitic losses, such devices do not exist within the electrical installation between your socket outlet and your electricity meter, unless they are deliberately introduced by wiring, or fitting a BS1363 socket with built in USB outlets for example.

However, the socket in your picture is simply a BS1363 socket outlet, it is a totally inert device, with no transistors, or other passive/active devices, thus it cannot "consume" power, and thus, there is no leakage, unless there is a dangerous fault within the installation, and if that fault were at the socket, it would manifest itself quite quickly.

So, unfortunately, your friend/other contact, is either misunderstanding the scenario for some reason, or, really does not understand the distribution side of electrical installations in premises.

"His" diagrams to not reflect how a distribution circuit to a BS1363 socket outlet is in real life.

His ac source, would be the socket outlet in these diagrams, the box of tricks would be the load, washing machine tumble dryer, phone charger supply, etc, and the switch on the socket would be up stream of that, the way that has been drawn is neutral switched, which is only allowed within appliances and devices built to a product standard.

 
I emailed that post from yesterday (with the 3x diagrams) over to "him", this was this morning's reply as I believe he may have taken the time to read the post and the Comments below that post.

"Interesting yes - but its not science.

Everyone is entitled to their own opinion but not their own facts.

If there is a voltage in a closed circuit (one that is switched on) there will be a current. [absolutely true]

Where there is a current there is power [Absolutely true]

W = A x V [Hmmmm. ask him if he knows what PF is]

That's science - sorry - don't care about opinion, its not evidence, Andy."


As he said, a "closed circuit" If there is nothing plugged in it is an open circuit and not a closed one....

Switching on the switch proves nothing, it is still NOT a closed circuit unless something is plugged in.

That is my final contribution to this. Where do you think this electricity is going?? Just floating off into the air????

john...

 
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Since we're here, how about:

1) the power usage of this humble USB / iPhone cable etc.Not attached to any device but it does run through an adaptor. Socket "on".

I don't have access to one, but more frequently one sees....

2) USB-specific wall sockets, which clearly do NOT need any third party adaptor (do they have an "on / off" switch?), so if they do, let us assume "on" again, as per image, with a cable, plugged-n but again, NOT attached to anything ?

Thank you in anticipation. 

_DSC6276.jpg

 
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and now he starts changing the question because he didnt get the answer he wanted...

USB sockets will use some power at all times. it should be possible to have a switch on them when a USB plug is inserted but im not aware of any that do

 
Incorrect.

I have merely added another dimension, expending upon the original, nothing more, in effect extrapolating out the scenario and circumstances.

From the very outset, I came here looking for answers, not with an opinion per se, just seeing wisdom, not abuse, just some knowledge I do not posses. 

 
Fata,

With nothing plugged into a socket, no power is being consumed.

There is an open circuit at the socket terminals.

Once you plug something in, then there is the potential for the circuit to be completed, thus power can be consumed.

Now, if you read, my earlier post, I have already answered the questions that you are now posting.

Please don't troll the forums.

You have had some sensible answers, and some from the forum comedians, and some from those who in their own words "don't suffer fools", and they make their own opinions on posters,

I have not labelled you as a fool, I have decided that you are one that does not understand, so I am trying to explain to you.

Nothing plugged into a socket, no power can be consumed, switch on or off.

In your second post you have now added something plugged into the socket, the device itself, does not have an inbuilt off switch.

This appears to be an Apple iPad power supply.

This contains a switch mode power supply. This contains passive components, and maybe even some active, so as long as there is power to the device, i.e. switch on, there will be parasitic losses in the unit, not least from the transformer, as you will have core losses due to the magnetising current.

Once the switch on the socket outlet is off, even if this device is plugged into the socket, no power can flow, thus no energy can be consumed.

Again as I said earlier, socket outlets with built in USB connectors do consume power at all times, as the power supply for the USB is independent of the switch for the BS1363 socket outlet part.

I have asked a few socket OEM's for their parasitic losses, but as yet none have replied.

These losses are again due to the SMPSU in the device to power the USB outlet.

These are permanently connected to the circuit, unlike anything connected via the socket outlet which are switch controlled.

 
Sidewinder - thank you.

Not forums, plural, just came here for one answer and expanded said question to three ultimately, so your comprehensive response is welcomed without advising me on who should and who should not procreate, again, welcomed.

I had looked elsewhere for an answer, without posing a direct question on any forum but here, that same question has clearly been posed before and there has been, as the link indicated, more than one answer elsewhere. So I thank you and others for their opinions - it sounds as though there is more still to come regarding the third question, and again, thank you for enquiring on my behalf.

 
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35 posts?

If there is nothing connected across the supply there will be no power drawn.

If something is connected it will draw power.

There is nothing more to be said. It is very simple. It does not need several people to explain it or come up with any counter-arguments, that is the fact of the matter. Devices connected to the mains draw power, devices not connected to anything do not draw any power.

 
baddayexplode      

So......   

is the "real" question here... 

does a USB phone charger (or similar device) consume power if the other end of the USB lead is not plugged into a Phone / Ipad / GoPro / Torch / 'Other USB powered item"...

Which IMHO is a reasonable question....

Or..  if the question is genuinely "does a socket with nothing plugged in consumer power"....    Then that has got to be a wind-up surely???

:C

I guess a similar question could be.....

Does a lamp emit light when switched on...

or absorb all of the light to make it dark when switched off???

:popcorn

 
And does a falling tree make a noise in a deserted forest? 

Why stop there ........... How can the universe be infinite ? 

What was here BEFORE the Big Bang ?

Is there a God?

All of Man's warring , killing , adventuring , great deeds , inventions and exploration of space , great institutions , universities .....have no effect upon the cockroach who trundles on about his business and , we are told,  will survive the nuclear holocaust.  

 
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