Plug sockets with integrated USB PSUs

[Mathew Newton]

When it comes to mains sockets with integrated USB power supplies do they only get powered up when a USB plug is inserted ala shaver sockets? I am considering putting one in a kitchen island which would be used very infrequently and hence would rather it not be sitting there wasting power (presumably very little) and not representing a fire risk (perhaps more a concern given how often USB power supplies have been found to be the cause of domestic fires).

The rest of our sockets are Volex and so that'd be my starting point for one, but would switch to another if this feature wasn't standard.

[Dave Plowman (News)]

All sockets should be mounted in a fire proof box. Conforming to regs.

I'm sure they do take a tiny current at all times. But then so will lots of things in your house. Like the clock in your oven, etc. TV if left plugged in and switched on at the socket.

[tabbypurr]

they normally run 24/7

NT

[Brian Reay]

All the ones I?ve seen lack any kind of switch.

They use a switch mode PSU and tend to be very efficient so, unless you are charging something, the standby power is really naff all.

As for fire risk, while nothing is ever 100% risk free in this respect, if you by a decent make etc and install it in correctly ( they should be in a fire proof back box) they are almost certainly safer than leaving USB charger plugged in, even when in use.

Personally, I think the batteries pose a greater risk while on charge- the real horror stories generally involve batteries rather than just chargers if you look at the details.

[Reentrant]

MK make shuttered USB charger modules. When nothing is inserted the shutter closes and completely disconnects the charging circuitry.

(Not that cheap, and don't include 13A 3-pin sockets)

[Brian Gaff (Sofa)]

It is always on, at least all the ones I've seen are basically mini wall warts of the switch mode which interfere with almost everything just wired across the mains with a thermal cut out.

What is wrong with just using a normal wall wart and unplugging it? Brian

[Mathew Newton]

That's an interesting point; are plastic plasterboard back boxes considered fireproof? Indeed are metal ones even given they gave holes in them?

Incidentally, this socket would be going in the side of a kitchen island and so would arguably be even more warranting of protection given the flammable surrounding materials.

[Brian Gaff (Sofa)]

I'm also not sure about some shaver sockets. One which a friend ripped out of a bathroom a while back had an isolating transformer in it for whatever reason, now obviously its not going touse much, but it must have been using something. Brian

[polygonum_on_google]

Our shaver sockets switch off when nothing is plugged in. I thoight that was pretty common, if not universal.

[polygonum_on_google]

A USB double-socket allows two mains devices AND two (or more) USB devices to be plugged in at the same time. Using wall warts means that the mains sockets are occupied.

[Andy Burns]

You can get a dual USB charger with 13A passthrough

[Chris Green]

Er, that's the whole point of a shaver socket, it has an isolating transformer in it so that 'mains' voltage is (relatively) safe in the bathroom.

[charles]

The reason is so that you don't have a live socket beside a wash basin which might well contain water.

[tabbypurr]

you still have that. But it becomes independantly floating IT rather than earthed neutral. There is some useful safety benefit, but it doesn't remove all shock risk.

NT

[Dave Plowman (News)]

Wonder about the service life of such switches?

[Terry Casey]

Poundland do one in white for £2 and I've got a similar one, also £2, which I think came from Wilko.

[ARW]

You can buy intumescent dry liners.

[polygonum_on_google]

True - but it is still something extra. And it is plugly. And it is quite expensive for what it is.

[Andy Burns]

Normal sockets would stay in place for decades, USB has a habit of changing connectors, voltages or currents every couple of years, how much more often will sockets with USB need replacing?

I guess they won't run that cool, being enclosed.

[Chris Green]

How cool they run would depend on their efficiency, and/or their power consumption when not providing power to a load.