Mains outlets with USB sockets - safety?

I've been replacing worn out mains sockets in the kitchen/bedrooms with the the type that have a couple of USB outlets as well as the mains. It's worked well - no more wall warts. But I've read posts here which suggest that wall warts can be dangerous and shouldn't be trusted for unattended, eg overnight, charging. Presumably the combined mains/USB units use the same sort of technology- are they dangerous does anyone know?

Robin

Nah, why should they be?

Sometimes you have to trust the people who design these things.

The MK offering is at a premium price but I do like MK stuff and it does seem to last well, it may be a total waste of money but I bought an MK USB socket in the hope I was getting a safe well made and well designed unit but I may have wasted my money. If you kill a £700 phone because the USB fails it could be an expensive buy.

Mike

I wouldn’t have a problem with a good quality socket that was 15 years old though it would probably look old. With a built in usb charger permanently connected to the mains supply, no thanks.

***** link *****

If you buy any electrical equipment in the UK, always make sure it carries the British Standard kite mark. In my past Electrician experience MK always had a premium price but it is good stuff, along wth Crabtree.

For charging I tend to read and follow the instructions for the particular device itself.

Ed.

Bear in mind that very little electronic equipment lasts more than ten years, often less than 5. So you may need to replace that whole socket several times over during the rest of your life. I suspect the first time it fails you will say sod it and just use an ordinary one. Plus the built in psu is using electricity all the time. We are encouraged to unplug even one psu not being used so what does half a dozen do to your CO2 emissions.

The unit I bought from Wickes failed after a couple of years but I’ve not yet replaced it. Are there any units on the market that are safe to use at the moment as I’d like to replace it soon?

I expect a lot of these devices draw load all the time. Just adds to the waste of energy, particularly when there are several running 24/365. Cheap wall warts are no better if left plugged in - they don’t overheat and go on fire when disconnected from the mains!

I look on these ‘convenience’ sockets as just another energy waster.

If I use my phone charger to charge my tablet the tablet posts up a message that I should use the original charger as the tablet charger is rated at 2Amp and the phone charger is only rated at 0.7Amp. I wonder if other items use different Amp rated chargers and what these socket mounted chargers are rated at. Will they overheat if i charge my tablet in one.

David

I charge an iphone7 and iPad simultaneously each night with no signs of distress and no complaint from the devices, as the socket is limited to 2A shared across the 2 USB outlets and current limited then the iPad is probably charged at a slower rate than its maximum. It has worked well for me for a couple of years now.

Mike

Hi Dave, I think it is a matter of time. I have an android tablet which has a mains charger, but it can be charged from a USB port on my laptop. The difference is the mains charger will fully charge it in less than half the time.

Regards Nick.

Sorry, can't agree with that. True equipment based on vacuum tubes (high voltages and lots of heat), weren't reliable and early transistors were rather delicate. Three-legged fuses we called them 50 years ago.

Well-made electronics have been more reliable than mechanical items for at least 30 years. The last car I scrapped had multiple mechanical issues after 15 years - corrosion, oil-seal failures, worn-out brake disks, weeping hydraulics, leaking fuel injector, steering that clunked turning right, and a suspicion the clutch was slipping. All the electronics, and there was rather a lot, were fine.

To answer the question, I'd happily install sockets with built-in USB power supplies wherever it was worth doing. I wouldn't fit them everywhere as a matter of course. They're handy in a kitchen or bedroom for recharging mobile phones etc. The way they are designed and made makes them rather safe; very unlikely that mains voltage could appear on the output, or that enough heat would be generated by a fault to start a fire. Any trouble and they fail open circuit. The same can't be said of transformer type wall-warts; they consume power off-load, can overheat, and shorted windings can catch fire without blowing a fuse.

As always, it makes sense to avoid buying cheap and nasty.

Dave

Have a look at Clive's review. **LINK**

You get what you pay for. He also strips down one from a reputable supplier

Brian

EDIT:  Personally I think the fire risk from good quality chargers is low, but how do you know something from Amazon Marketplace or eBay is what it claims to be?  The supply chain to a trade counter should be much more reliable, and these sockets put the charger inside a flame retardant housing.

Edited By Brian G on 06/07/2019 10:52:58

Sorry Dave, but that's just not true. Modern electronics are not long life. The reduction ic size is the biggest problem as it causes higer power density and voltage gradients. The most common failure compnent is electrolytic capacitors.Many have specified lives (at max rating) of only a few thousand hours. Electronic failures are the most expensive repair on modern cars. This is not helped by technicians who just change boxes.
I have laptops that are twenty years old and still working fine. more modern, faster slimmer models from the same manufacturer have only lasted 3 to 5 years.
The USB outlet sockets fall between regulaton and all of them draw some stanby current. By physically having components they must be more of a fire hazard than a simple socket. They also add to the background electronic noise.

Robert G8RPI.

I’ve had a quick look at the MK and Crabtree offerings and the latter one said it was compliant with the latest regs. I generally used to prefer Crabtree stuff because it looked more modern than the MK stuff. Some years back though MK caught up and I don't mind either these days. They’re both about the same price but the Crabtree needs a 35mm back box and the MK only a 25mm. MK it is then next time I’m passing close to screwfix.

I didn't say electronics were long-life, I said 'Well-made electronics have been more reliable than mechanical items for at least 30 years.'

Certainly putting electronics in a socket makes it more of a fire hazard but so does applying power to an ordinary one! Fairer questions are 'how much' and 'does it matter'? Early days maybe, but lack of houses burning down due to faulty USB modules in power sockets suggests they aren't high-risk.

The other useful comparison is between the fire-hazard caused by a USB module in the wall, and the fire-hazard caused by a USB power supply inside the room, perhaps one cooking-off on an inflammable sofa. Could be internal USB PSUs are a safer bet when the entire risk chain is considered.

The electrical noise sprayed about by pulse mode power supplies is reprehensible!

Dave

In a car load of stuff I took to the tip today were two MK double 13A BS1361 mains sockets. Both had failed by welding the contacts closed when connecting a 10A rated load (somewhat capacitative)...

Thanks for replies. I feel somewhat reassured - generally I adopt Peter Spink's attitude and trust the designers (or at least to the bodies who set evidence-led standards), but there were some posts on here about wall warts which made me wonder about the safety of these things. Following the links folk have provided it looks like it is indeed early days and there are no standards yet. I like standards because I am in favour of consumer choice and there are so many of them (sorry, ancient joke). The ones I bought were from Screwfix and not particularly cheap, about 11 quid IIRC so maybe they're OK. They certainly don't get warm to the touch even when charging.

Looking at the investigations which have been linked to, it seems that that most of problems are to do with proximity of components/poor insulation rather than failure of individual electronic components. Maybe I'll dissect one and look...

I'm not too worried about the financial overhead after looking at my leccy bill today - average use 16kWh per day? I doubt that's the USB sockets, I have other things to address obviously!

Brought to you through a Netgear router which has been running 24/7 for 18 years,

Robin.

Edited By Robin Graham on 08/07/2019 00:55:07

Out here , the accessory insert as we call them, can be changed out at any time or replaced and swapped with what ever you want, as log as they make the modules to fit that form factor of outlet or switch. So you can have a USB charge point, or a sensor to turn on the power point or light , or it can have a timer etc. It does give you some forward protection of obsolescence. In 5 years time, the now common USB port will not be very common at all. So for that reason, we are only putting in 3 usb power points and we are getting the latest design of power point with the new form factor for the swappable components.

An example is out here a vertical power switch is cheaper than a horizontal power switch. But the vertical one, just needs the switch module turned 90 deg and it becomes the horizontal for no extra cost. Some brands don't have modules at all, so a whole replacement is required. The modules are around 2/3 the price of the cheap non module switches and power points.

I like the 2amp usb charge ports we have so far and think they are great. The area does not get warm at all and it does not take up a power point to recharge the phone.

Neil