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Last summer I took my laptop on a trip from the U.S. to Austria. It is an Alienware (Dell) and the power cord has a ground pin and is rated 100-240V, 50-60Hz. I used an adapter to plug into the C European electrical socket. In both hotels I stayed at I flipped the breaker to my room while using my laptop. I thought there would be no issue since the laptop was rated 100-240V. What could have caused this and how do I prevent it in the future? I am going back to Austria and Italy this summer and do not want the same thing to happen again.

I only had one adaptor, so I couldn't try any others. I charged my phone and tablet through it with no problems. It came from Target.

To add additional information, the breaker did not trip immediately. In the first hotel it happened after about 30 minutes of using the laptop and at the second one it happened after a couple of hours of use. Does that make a difference? As I mentioned in the comments, my power cord has a ground pin and the adapter was for a Type C outlet so the ground pin did not go into the adapter. I'm also certain it was being plugged into a type F outlet, which is grounded.

  • Comments are not for extended discussion; this conversation has been moved to chat. – JoErNanO Jan 25 '18 at 2:22
  • @mallen: the information given in the answers could be useful to many, but let's be honest...right now it's impossible to know what's the right answer, so much of this question usefulness is getting lost. I'm going to suggest...why don't you write an email to the hotel to ask them if there is a "hotel related reason" for what happened? – motoDrizzt Jan 30 '18 at 8:31
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A breaker tripping is a serious sign of trouble. Something shorted or started to draw excessive current. If not for the breaker, it would probably have caught fire. (Or the circuit was already overloaded - but since it happened in two different places, that seems unlikely.) So this is a safety hazard if not resolved.

Since it doesn't happen normally, I think the most likely suspect is the plug adapter. They're often cheaply made, and I could imagine that a manufacturing defect, or damage from rough plugging and unplugging, could give you a situation with an intermittent short. So I would start by replacing the adapter with one of known good quality - look for certifications. And be careful not to damage it.

Then if it happens again, I would suspect the laptop's power cord or power supply, and replace those.

And until you are confident the problem is resolved, I would suggest keeping an eye on the laptop, and not leave it plugged in when unattended.

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    One alternative to getting a high-quality adapter: if the laptop AC adaptor has a mains socket (rather than a hard-wired plug or cable) you can buy or borrow a European mains cable and use that instead of the US cable. From some googling it seems that Alienware use the very widespread C13 connector for mains input on their laptop adaptors. If there's a kettle, fridge, or TV in the hotel room, there might be one of these already available for use. – Pont Jan 23 '18 at 7:05
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    Or for a few dollars you can purchase an EU C13 on Amazon. – Tim Jan 23 '18 at 7:44
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    @alastair - a good switch mode supply should not be leaking milliamps to ground - that would trip any functioning GFCI on the planet. In fact, a good switch mode supply should not be leaking current to ground, period. – Jon Custer Jan 23 '18 at 14:28
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    @alastair: Ah, that's a good thought. I took OP's "tripped the breaker" literally but it could be that they have confused the circuit breaker with the GFCI. (Incidentally, many of the laptop power supplies I've seen in the US are designed with no ground pin (two prong plug), so they aren't capable of leaking current anywhere - but OP's could be different.) – Nate Eldredge Jan 23 '18 at 15:11
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    @JonCuster Indeed you don't have to earth a switching supply, but then in order to suppress EMI you have to attach a class Y capacitor to either the live or the neutral (since many countries' plugs are reversible, there's no way to know which). The problem with that is that you can't make the capacitor too large because that would result in the DC side of the supply being dangerous to touch. Earthing the supply solves that problem, as you can connect your capacitor to earth instead, but that, of course, means some current can flow to earth. – alastair Jan 23 '18 at 15:22
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It looks like your laptop is tripping the RCD rather than the regular circuit breaker: a device tripping the regular CB will simply start smoking if the CB doesn't trip, and your laptop seems to work in some places. AFAIK RCD protective devices are mandatory in hotels in the EU.

While this is sometimes due to the power supply design and not an actual problem, it's better to be safe than sorry. Chances are, your PSU is leaking current from high-voltage part into the low-voltage circuitry, putting you at risk. This may be not noticeable while the current is low, but the danger is that it can increase unpredictably.

The cheapest step to take is to replace the power cord. If that doesn't help, get the power supply checked by a repair shop, or buy a new one.

People sometimes suggest to get a power cord without protective earth pin, which indeed will get your power supply working, without tripping any protection. Don't. When the power supply will die of old age, you will have no residual current device to protect you and rely solely on your health to sustain the electric shock.

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    This does seem the most likely suggestion. – alastair Jan 23 '18 at 13:03
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    This seems less likely because the OP refers to the socket and adapter as a Type "C", which is a 2 pin plug with no connection to ground. A grounded adapter plug for Austria would be a Type F. – Dennis Jan 23 '18 at 17:24
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    @Dennis Type C? Are you talking about "C European"? I think he meant "central European". – Sneftel Jan 23 '18 at 19:14
  • @Dennis Let's wait for the OP to clarify this. If the adapter really has a C13 connector (as suggested by Pont), a ground pin should be present. – Dmitry Grigoryev Jan 23 '18 at 20:54
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    My adapter is a 2 pin ungrounded plug. – mallen Jan 23 '18 at 21:14
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I have a gaming Laptop too and live in Austria. The switched power supply provided with my laptop seems to have an extremely high inrush current. This is in general common for such power supplies, but the one provided with my laptop is extremely bad.

Breakers have different characteristics and it takes them a different time until they flip.

In one part of my parents home there is a older electrical installation, and I can't plug my laptop in there without flipping a breaker. The rest of the house has newer electrical installation, and there it works.

I also have an DC-AC converter rated 500W for my car. My laptop power supply is rated 300W, so it should work. I cannot connect my laptop to this, it immediately trips some internal breaker. Just for fun and to confirm my suspicion I connected a UPS in between. So Converter -> UPS -> Laptop power supply. This works.

After I found the reason is indeed the inrush current of the power supply I bought a generic 350W power supply which is compatible with the laptop. This one seems to be of better quality and has none of this problems.

So I believe the most likely problem is, that your power supply just draws to much current when powering up.

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    It's possible that it could be inrush current, but if so then it's worth noting that the maximum inrush current is where the device is switched on at the peak of the AC waveform. You wouldn't expect that to happen every time — i.e. you'd expect this problem to be somewhat intermittent. – alastair Jan 23 '18 at 13:04
  • There is something wrong with a mains supply that balks at charging up a capacitor smaller than my thumb:( – Martin James Jan 24 '18 at 5:28
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    I super doubt it's inrush. Enough inrush to trip a 16A building-grade breaker is like 18kw for over a second. That's 18k joules. It would make the adapter instantly hot. The RCD theory is the best bet IMO. – Harper Jan 24 '18 at 9:01
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    @Harper I strongly suspect that many hotel's breakers (at least, those protecting guest bedrooms) will be considerably lower than 16A. – TripeHound Jan 24 '18 at 10:34
  • @Harper I am nowhere near my parents home now so I can't check which model it is exactly, but the breaker trips almost instantly, so nowhere near a second time. Also the breaker is 16A in this case, but of course a lot of other stuff is connected there so it isn't just the laptop that needs to draw all the current. – Josef Jan 24 '18 at 11:39
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I agree with all other answers and I would pay a lot of attention to the security things, but just to add a small thing that could have been overlooked: at least in Italy it's not uncommon for hotels to not allow the use of any electrical appliances at all, or sometime to allow only a cellphone charger or an electric shaver.

In the first case you'll not find any plug in the room, in the second case you'll simply have the room spare plugs connected to a different breaker: it's entirely possible that an Alienware, at boot, would trigger it.

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    This. Everyone seems to be concerned with the safety aspect, but it's definitely possibly they have current limiting to stop people from using high-power devices. A highly-spec'd laptop over a couple of hundred watts could hit this limit. I wouldn't expect a high-quality laptop with original power supply to trigger any kind of breaker unless (1) it was faulty (in which case it'll trip any plug circuit it's plugged into) or (2) there was some kind of additional current limiting protection in the plug circuit. – stanri Jan 23 '18 at 10:57
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    @stanri The third option that comes to mind is the OP having a more lax protection limit at home, while the hotels have a more strict one. – Dmitry Grigoryev Jan 23 '18 at 12:32
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    Wow. I will make sure to check hotel reviews more closely before visiting Italy again. Such a restriction would be a deal-breaker (no pun intended) for me on a hotel room and I suspect also for a large percentage of today's travelers. Also, if the hotel is so cheap that they won't let you use a few cents worth of electricity, that makes me wonder what else they're cutting corners on. A proper cleaning of the room costs far more than those few cents, for example. – reirab Jan 23 '18 at 16:14
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    I often think Italians seem to go out of their way to be jerks for tourists. My wife dreams of visiting italy, and I honestly am a bit wary of the idea. Nevertheless thanks for the tip, if we visit we will use tripadvisor to avoid such places. – Rui F Ribeiro Jan 23 '18 at 17:02
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    I’ve stayed in numerous places in Italy, and I have never encountered any hotel policy as described by you. Especially in Italy, a policy which doesn’t allow cell phone chargers would be ignored by everyone but the most naïve foreigners. What I’ve seen (though I can’t say of that was in Italy) was a policy asking guests not to use household appliances (such as irons or water kettles) in their rooms. In any case, I’d be really surprised to find a hotel policy which bans laptop AC adapters. – user149408 Jan 23 '18 at 21:44
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It's probably a ground fault. You want to know - in America - whether your laptop power supply has a ground fault, so you can get it fixed now.

Easy to test. In the United States, find a GFCI protected circuit, found in the newest kitchens, bathrooms, garages, laundry rooms, etc. You can also install a GFCI that replaces a receptacle, they cost about $20. Europeans call it an RCD, for residual current. Same thing.

Plug into the GFCI and see if it trips. If it does, it will trip a European RCD. Don't fool around with ground faults, especially if you travel. Your bad power supply can combine with a hotel's old and faulty electrical service to shock you.

GFCI/RCD compare current flow on both conductors - they must be equal or current is leaking somewhere to a third path (usually to a safety ground, which requires a ground - that can't happen with a 2-prong plug. Sometimes another way, e.g. through a human.) By nature, they trip instantly (well, 8-10 milliseconds) because a goal is life safety.

GFCIs are uncommon in American homes, but very common in Europe. Europe protects the whole dwelling with a low sensitivity unit (30 milliamps). America protects only high-risk rooms with a more sensitive unit (8ma), and it's easier to distinguish whether it was an overload trip or a GFCI trip.


If it's not a ground fault, it must be an overcurrent trip. You say in a comment elsehwere that the trip was instant, not even 1 sec - that means if not RCD, the breaker must be operating in magnetic-trip mode (not delayed thermal trip). Magnetic trip requires massive overload on the order of 150A++ (30++kw). It's difficult to believe that would not have noticeable effects like arc flash, audible report, notable heat, burnt plastic smell, visible damage. As such I consider it unlikely and suspect RCD.

It's not inrush current on power-up. Almost everything has that - motors, incandescent lights, almost any power supply including electronic ballasts in fluorescents and LEDs. Circuit breakers listed for building wiring factor for this with a delayed thermal trip regime. Cheapie breakers on power strips etc. are made to be more sensitive (they want to trip before the service breaker.)

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    Presumably, a 110V GFCI will be less sensitive to faulty components than a 220V one (assuming the trip current is constant). Also, OP says the trip occurred after 1/2 hour or more of operation, implying the fault condition was marginal (but still likely a ground fault in need of remedy). – Sean Houlihane Jan 25 '18 at 14:28
  • @SeanHoulihane OP stated in a comment elsewhere that it was instant. That in response to a discussion of overlaods (1-30 sec) vs bolted fault (instant) or ground fault (instant). There's no "presumably" to it: as I say, Europe uses 30ma devices (at 220-240V obviously) and US uses 8ma devices at 120V. Those choices reflect different philosophies by the rulemakers - much like the "washing eggs" issue. If you want that expanded, discussion exists on diy.se. – Harper Jan 25 '18 at 17:41
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If the problem does turn out to be an unreliable plug converter, you don't necessarily need to buy yourself an expensive, high-quality replacement converter. If the laptop power supply has a mains socket (rather than a hard-wired plug or cable) you can swap out the mains cable itself: buy or borrow a European mains cable and use that instead of the US cable. From some googling it seems that Alienware laptop power supplies use the very widespread C13 connector.

C13 connector
Image source: Quail Blog

These may well be available more cheaply than a high-quality power plug converter, and using one eliminates one potential point of failure. If there's a kettle, fridge, or TV in your hotel room, there might be one of these already available for use, or you may be able to borrow one from reception. (At least in my experience, they seem to breed in dark corners and I always have far more than I know what to do with.)

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    +1 That being exactly the purpose of the C13 connector. One featurebug is that C13 is voltage agnostic, it's not keyed any different for 120V vs 230V. That's barely a problem today with almost everything having multivoltage switching power supplies, but older PCs had to throw a 120/240 switch. – Harper Jan 26 '18 at 8:45
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All these answers are reasonable, but one more possibility occurs to me …

Did each hotel room have its own breaker? The variable and long delay before tripping sounds like it tripped when someone else added a load to the same breaker.

I've seen it happen when someone puts down toast while a microwave oven is on, or starts a hairdryer while someone else is vacuuming.

Could even be something in the same room that is intermittent, like a thermostat-controlled heater, or a refrigerator. It might come on, but you don't hear it because the breaker immediately trips.

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