I have solved one of life’s little mysteries: The explanation and use case for the “Shavers Only” electrical outlets found at many hotels.
I’ve long puzzled over the meaning and origin of the “shavers only” electrical outlets found at many hotels. They’re ubiquitous in Europe and Australia, and appear to offer 110 volt AC with an American-style two-prong socket. They’re always found in the bathroom, where I’ve even spotted them in older American homes!
An Electrician Explains the Shaver Socket
It’s very tempting to plug American devices into these sockets when traveling, especially when (as is so often the case for me) a suitable converter is unavailable. But should they be used for anything but shavers? After all, they are very clearly labeled. And what’s so special about shavers anyway?
Chatting with a seatmate on my long flight to Australia, I discovered he was an electrician who works in commercial sites. I jumped at the opportunity to inquire about this hotel electrical puzzle, and he quickly laid bare the mystery.
Simply put, these “shavers only” plugs are indeed suitable for most other modern electronics provided they do not draw much power and are not sensitive to frequency differences. In other words, it’s probably fine to use most “shavers only” plugs for most small solid-state electronics, including phone chargers. But you should avoid using them to power laptops, hairdryers, curling irons, or other high-draw devices.
Shocking History
So why are most worldwide hotel bathrooms equipped with a special low-power outlet? It’s not at all shocking. Literally! Before the invention and widespread use of Ground Fault Circuit Interrupter (GFCI) devices in the last few decades, there was great concern about providing electrical power near water for fear of electrocution. An electrical outlet in the bathroom was an accident waiting to happen.
Since the 220-240 volt systems common outside North America increase the danger of electrical shock, many of these countries adopted a special low-power outlet for bathroom use. The UK and some others use a “Euro style” two-round-prong plug, while many other countries use the American flat-prong plug or their local style.
Regardless of the plug or socket used, these “shavers only” sockets share another common feature: They severely restrict power output using a fuse or modern GFCI device. UK sockets are supposed to limit output to just 200 mA, while other standards allow a range of 20 to 40 Watts (which is pretty much the same thing in different units). Either way, we’re talking pretty limited power – an iPad charger can draw twice this much, and a laptop far more!
One more thing: Although these outlets step the voltage down to 110 V, they do not modify the frequency. So shaver outlets in countries with 50 Hz power systems will have the odd 110 V, 50 Hz combination. This is no problem for most modern DC electronics, but might cause issues for older electric appliances that sync to the power line frequency.
What’s the worst that could happen? You could get electrocuted and die. Barring that, it is very unlikely that electronics will be damaged by these sockets. But high-power electric devices could overload the socket and blow a fuse.
Stephen’s Stance
I will not advise others to risk life and limb through improper use of electrical power. Now that I know that “shavers only” sockets are indeed fairly standard, if limited-power, 110 V AC sources, I personally will not hesitate to plug my phone charger into them. But everyone should be very careful with electricity, especially in wet and unfamiliar environments like hotel bathrooms!
>What’s the worst that could happen? You could get electrocuted and die.
It’s amazing how often that answer comes up in my life.
I believe that’s called “lawyering up!”
Seriously, you have a phone that did not come with a switching power supply?? I’m trying to remember the last portable device I got without a multi-voltage (110-250v/50-60 cycles) power dongle.
Strictly speaking we are all going to die, so electrocuted and die earlier than expected. I use my shaver socket to run a battery charger and suspect the transformers are not intended for long operations as some seem to run quite hot. So burn the hotel down might be added to the worst case list.
Of course everything has a switching power supply these days. But unfortunately, the world has no standard for the physical form factor of electrical plugs, and I often find myself without the correct one when traveling. It’s nice to know that just about every hotel is fitted with an American style electrical plug that can be used for powering your phone!
I carry a heavy-duty “US” extension cord and one of the appropriate plug adapter(s). So all of my switching supplies go into that extension cord, and it gets plugged into the normal local power output.
A nugget of information I’ve wondered about numerous times. Thanks for educating us !
what a good idea! i struggle with never having enough adapters.
Very good post thanks……………….
These sockets can also be found in the bathrooms of some Belgian trains.
I used a 110 shaver in Sweden and it blew up the battery on my iPhone 4s. I do not recommend using a shaver outlet for anything other than a shaver. Coincidence, maybe, but I suggest caution and buying a ‘normal’ plug converter gadget for a couple of bucks for traveling.
but everyone wants to dry their hair in the bathroom mirror!
Thanks for this useful info Stephen. Based on my experience, I previously think that shaver sockets are ok for short term use. And it is not designed for continually use, which may cause the thing you plug there stop working or the socket will.
Hi Steven. You are somewhat off base with this, as the “limited power” you speak off has NOTHING to do with bathroom safety. These “special” bathroom outlets have a safety isolating transformer integral to their wiring, which electrically isolates the output circuits from the incoming supply, and, means that if you do contact one of the conductors (say if there is a cut in the flex, and you touch it with a wet hand), there will be no current path to earth. That is why you notice, that they do not have an earth pin (ie only two pins on a shaver plug).
The fact that they only have limited power out, is only that the transformer is small, as it needs to fit within the constraints of the back box. It has no bearing on the safety aspect whatsoever.
How about electric razors that are larger
This is a disappointing read. When I was in the UK last April I often wondered if I could plug my curling iron into the shaver only socket and at least have a mirror to curl my hair, But I found this site and again on my trip to Scotland this April I will have to try to curl my hair without a mirror. This really sucks!
Even with an adapter, I found most of my electronics ran rather hot. Why is that?
I’ve just purchased a US toothbrush and now need an adapter to make it compatible with my UK shave point which is 240 or 110v depending which socket I use. Any recommendations?
“UK sockets are supposed to limit output to just 200 mA, while other standards allow a range of 20 to 40 Watts (which is pretty much the same thing in different units). Either way, we’re talking pretty limited power – an iPad charger can draw twice this much, and a laptop far more!”
80w ipad charge bahah what? watts and amps pretty much the same? dude, what is this a gawker media spin off ? those statements are so far from accurate.
first
lightning is just usb 2.0 with an apple patent connector. if I were to say it maxed around 2 amps (when standard is adhered to) could you tell me what its wattage is with out googling?
f not perhaps you shouldnt make such statements.
watts = volts * amps
watts are a measure of energy. in electrical terms volts are used in calculating them but are not the same concept. The reason we deliver power at a higher voltage than say usb’s 5 is people want a lot of WATTs…that sounds trolish but its serious lol. If you decrease the voltage, you increase the amperage to deliver the same amount of watts. more amps requires thicker wire and or = more heat.
so lets say the uk standard is used… 120volts * 0.2A = 24 watts
as i mentioned , lightning is really usb 2.0. so you are charging at 5v. how many amps can 24w deliver @ 5v?
watts/volts = amps
24/5 = 4.8a
in other words you could charge 2x pre 2017 ipads or iphones and still have 800ma to spare… on the lowest power standard you mentioned.
back when you wrote this i doubt apple even had the 12 watt charger older models can now use
2017 iphones and ipads got usb c iirc. idk why apple users or reviewers dont seem to understand one can plug a meter in line… aka the best i could find was a gawker media article where the guy paid to vomit on screens went out and bought usb c chargers of different wattages to test how fast the new i devices could charge.
none of them had a charge speed increase passed the 21w charger.
devices draw power. chargers are capable of supplying up to the wattage listed but they dont push say 60w or X amps … the device draws what its configuration either allows by e=i*r or by what the power control chip in it decides it should be getting …which is still limited by the aforementioned e=i*r
as for apples new 21w devices…
this actually makes a lot of sense if you know jack about lithium ion cells. they have whats called a “c” rating which helps one determine how much u can draw and how fast to charge, 1*c is the cells mAh rating. 2c is 2x. get it? fastest its ever recommended to charge a lipo cell is 2c.
the power converter in the phone needs to dissipate and everything has to stay with in a safe temp are the other limiting factors. Faster you charge is generally worse for battery longevity as well.
if one did the math after looking up how big the batteries are in said devices, you will find they are likely a bit bellow 2c. the i pad possibly could have charged a lot faster but the power conversion chips to handle that would be more expensive…more heat to get rid of etc.
im guessing iphone x has around a 2600mha bat (didnt look but that number is pretty close for that class of phone) so 2c would be charging at 5.2amps.
last: the other commenter who mentioned the isolation transformer was correct. you would have to grab both wires to get electrocuted with that system. a gfci is almost as good. question is are you better than using emotion while not doing your homework or are you going to keep rolling the way you did?
ive written 2 attempts to correct some glaring errors in yoru article and both are flagged spam. almost every premise you make is wrong. the only thing you are correct about is they wont power most laptops. Im assuming you know algebra?
watts = volts * amps. even the uk socket provides 4.8amps at 5v
120volts *0.2amps = 24 watts
24w/5v = 4.8a
thats actually enough to even fast charge a usb c apple tablet or smart phone. a gawker media post tried various wattages and found the charge time didnt decrease above the 21w model. remember devices draw power the supply doesnt push it. There is a benifit to a larger supply though, it will run cooler in most cases but i digress.
the safety and risk of electrocution on top of these flawed premises makes this a huge click bait post. the guy who mentioned isolation transformers is correct. that means u would need to grab both ends coming out of socket. The voltage is no longer referenced to earth at that point…only the other wire from socket. To die from it you would probably need to do it across the heart. ie one wire in each hand.
the path energy takes through your body has a lot to do with how much harm it does. you would probably get a burn if both wires contacted the same hand, but your bodies OUCH HOT responce would be sufficient to stop it…
look at greg dope…he thinks he learned from you, are you going to leave this article as is or be a credible source of info?
even 4 years ago most gadgets had power supply that already handles either voltage, either you had a bunk charger or a bunk outlet. If you pay attention to a pc laptop power supply you will notice the wall part of the cord comes out. that same supply is sold to every country but they put the specific cord in the box. If you read the writing on said supply it will state something like
input voltage: 80-260 VAC
I was going to comment and say exactly what you did.
I am an electrician as I suppose you are.
The safety aspect doesn’t make sense, because people also use hairdryers in the bathroom, and hair dryers draw a lot more than 40 watts, therefore would have to be plugged into a standard outlet anyway, negating safety.
I come from Europe. This was explained to us in physics class in middle school, when we learned about transformers and electrical induction. Inside the outlet there is a transformer outputting 240v and 110v that naturally creates an air gap between hot and ground. So if you touch the hot and water at the same time you don’t get electrocuted. There is no fuse to limit power. Power is limited by the transformer coils. To have a high power transformer inside an outlet is not possible physically because of space limitations. That’s why they are limited to shavers only. With transformers the electric cycles remain the same as the mains.