13A sockets with integrated USB charging

[rusky]

I noticed that when I had the micro USB connector in my hand I got a tingling. Upon checking, there is 100Vac between the micro USB connector & earth.

Am I missing something or is this definitely not right?!

[Feanor]

It's probably OK.
This is common in lots of appliances that have 2-core mains leads.

I expect that the USB power supply inside the socket is a 2-wire design, with only a L and N feeding it.
It probably has a mains filter, which leaks by design to the PSU ground, which is not connected to the mains ground.
Thus the PSU ground floats at 1/2 mains voltage, but at a very high impedance ( ie low current ).
This is perfectly common in things like TVs etc.

I can't thing of any good reason the PSU ground is not connected to the mains ground, since it is right there and does not require any extra cabling, but there may indeed be a reason.

The first person to suggest 'hum loops' in this scenario gets strangled with a Russ Andrews mains lead.

[rusky]

Thanks for the reply & details

[Polar Bear]

As a supplementary if I may:  Why would I buy and fit these instead of just using a wall wart when required?   Is the 'always on' actually draining electricity, albeit a very small amount?

[Feanor]

As a supplementary if I may:  Why would I buy and fit these instead of just using a wall wart when required?   Is the 'always on' actually draining electricity, albeit a very small amount?

Tidiness, really.
Excessive wall-wartage can become a problem sometimes.
Leaves the 240v outputs free.
I have some 6-output USB chargers which reduce the wall-wartage, esp. when travelling.

Is the 'always on' actually draining electricity, albeit a very small amount?

Yes, I expect so.
But as you say, a very small amount.

[Kim]

As a supplementary if I may:  Why would I buy and fit these instead of just using a wall wart when required?   Is the 'always on' actually draining electricity, albeit a very small amount?

To provide a convenience for people in public places, or to free up a socket or two where space is at a premium.

Yes, I expect the regulator is always on.  No, I wouldn't worry about it.

[pcolbeck]

As a supplementary if I may:  Why would I buy and fit these instead of just using a wall wart when required?   Is the 'always on' actually draining electricity, albeit a very small amount?

I,m looking at buyingone to tidy up yhe bedroom TV. Its wall mounted wigh a single socket behind it. The TV doesnt provide enough power on its USB socket to drive the Amazon Fire Stick. Curently there is a USB cable trailing downthe wall to a USB wallwart inthe nearest floor level socket. Mrs Pcolbeck says this is not a good thing so a single socket with USB will be replacing the currentone behind the TV.