3-prong to 2-prong for laptop? & overseas?

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ResearchMed
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3-prong to 2-prong for laptop? & overseas?

Post by ResearchMed » Mon Apr 21, 2014 9:12 am

My current (no pun intended) Lenovo has a 3-prong plug.

All of the other (many) assorted laptops we've had over the years have had 2-prong plugs.

The 3-prong plug causes annoyance and sometimes difficulty when traveling, and even here at home in a very old house, as many places don't have many/any 3-prong outlets.

1) What risk is there to the laptop innards in using an adaptor to force the 3-prong plug to fit into a 2-prong outlet?
Am I likely to fry the laptop? Corrupt data? Or ?

The Lenovo power source adaptor indicates it can handle 100-240V and 50-60Hz.
(So does DH's laptop w a 2-prong plug, plus his electric razor, and assorted power cords for cell phones, etc.)

We will be traveling to Rome and Florence next month, and will be taking a few cruises starting in a few months.

2) What type of power adapter (not # of prongs) is needed for overseas travel?
(This affects other devices as well, of course.) Does the variability of the power adaptor make a difference for this?

Will the power on ships pose any additional problems (regardless of number of prongs)?

Thanks.

RM

hicabob
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by hicabob » Mon Apr 21, 2014 9:20 am

Software person here (but I have worked with ee's for decades :D ) - the 3 prong adapter will almost certainly ground the power brick only - not the computer. If there is a wiring fault in the brick (very unlikely) the ground is nice to have - that being said I have used my 3-prong Lenovo brick with a 2 prong adapter many places around the world and not had any problems.

linguini
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by linguini » Mon Apr 21, 2014 9:23 am

There are two things you have to look out for: the voltage and the plug type. Laptop chargers almost always take a wide range of voltage and work fine for any standard. Italy will probably be somewhere in the 220V range which should work fine. You will need a europlug adapter, which should take in a three pronged US plug and have two circle prongs sticking out. I have used this sort of adapter in South America and it worked great for laptops and cell phones. Do not use them for other devices which may not be rated for European voltage and frequency.

I would expect a cruise ship to have a range of sockets for international travelers, but you should call and ask.

EDIT: I just noticed you mentioned "a variety" of cell phone chargers. The standard microusb ones work great worldwide. I do not know what types of chargers you are describing in your post, so please verify before trying.

ResearchMed
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by ResearchMed » Mon Apr 21, 2014 9:45 am

hicabob wrote:Software person here (but I have worked with ee's for decades :D ) - the 3 prong adapter will almost certainly ground the power brick only - not the computer. If there is a wiring fault in the brick (very unlikely) the ground is nice to have - that being said I have used my 3-prong Lenovo brick with a 2 prong adapter many places around the world and not had any problems.
Thanks very much.

This risk would be about the same as using a laptop whose power cord only has a 2-prong plug to begin with?
It's another level of protection?

Or is the power adaptor *different* when initially configured with a 3-prong cord?

Years ago, we'd force a 3-prong into the cheapie 2-prong adaptor. But it's one thing to risk frying a small appliance with no data, and another entirely to deal with a laptop.
(I didn't realize this Lenovo had a 3-prong plug until it arrived. All of our previous IBM/Lenovo laptops have had 2-prong plugs, as have all other brands. Other than that, it's been a great machine.)

Thanks again.

RM

mmmodem
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by mmmodem » Mon Apr 21, 2014 10:03 am

I have yet to encounter a portable electronic device made in the last two decades that isn't compatible with higher voltage electricity anywhere in the world. Just look on the AC adapter and it will tell you. You just need an adapter for the plug and it will work. My tour guide from awhile back told me this and so far like I said every device has that 100-240V specification on the backside of the plug. Make sure you check! Don't just take my word for it!

The third prong is ground for safety. I am not an EE so I am not an expert. It's for surge suppression as far as I know so you put your device at greater risk of frying from electricity spikes without it. It's especially important for power hungry devices like a bigger laptop. I'd be wary of using an adapter. Given a choice, I wouldn't use an adapter and search for a three prong outlet. But if it was my only laptop, then it's a low enough risk that I don't worry too much either. You may feel different about your own laptop.
Last edited by mmmodem on Mon Apr 21, 2014 10:06 am, edited 1 time in total.

hicabob
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by hicabob » Mon Apr 21, 2014 10:06 am

I'm far from a "certifications guy" (but I have worked with a few of those too over the years :D ) but my WAG is that the 3 prong is to satisfy the certs for some particular country when a brick is over a certain power ... and bigger Lenovo's tend to have big and powerful bricks. Without seeing the schematic I wouldn't guess at the circuitry difference but personally I would not worry about it. Of course if a ground is available and you have the proper adapter it is always prudent to use it.

Double check on the voltage on all the stuff you will be plugging in - From experience inadvertently plugging in a 120 volts only (shame on tektronix!) scope wall-wart into 220 volts Oz mains makes an impressive bang when it explodes after a few seconds of valiantly trying!

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Don_Qua
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by Don_Qua » Mon Apr 21, 2014 12:08 pm

I'm in the same old boat that you're in; old house with old 2 prong wiring and I go overseas to 220v places with fat British and 2 prong European style plugs. I took a low tech approach to this and simply cut off the grounding pin on the plug to the laptop's power brick. I pack an adapter plug and my Acer laptop does just fine on 220v, 240v and even 100v and has never complained about the lack of grounding pin.

linguini
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by linguini » Mon Apr 21, 2014 1:35 pm

ResearchMed wrote:
hicabob wrote:Software person here (but I have worked with ee's for decades :D ) - the 3 prong adapter will almost certainly ground the power brick only - not the computer. If there is a wiring fault in the brick (very unlikely) the ground is nice to have - that being said I have used my 3-prong Lenovo brick with a 2 prong adapter many places around the world and not had any problems.
Thanks very much.

This risk would be about the same as using a laptop whose power cord only has a 2-prong plug to begin with?
It's another level of protection?

Or is the power adaptor *different* when initially configured with a 3-prong cord?

Years ago, we'd force a 3-prong into the cheapie 2-prong adaptor. But it's one thing to risk frying a small appliance with no data, and another entirely to deal with a laptop.
(I didn't realize this Lenovo had a 3-prong plug until it arrived. All of our previous IBM/Lenovo laptops have had 2-prong plugs, as have all other brands. Other than that, it's been a great machine.)

Thanks again.

RM
I don't think it's really necessary, but if you are really intent on grounding, then there are some adapters that will support it. You will need a NEMA 5 to CEI 23-16 adapter, which will only work in Italy because grounding works differently in different European countries. (Almost all countries in continental Europe and southern South America and possibly more I don't know about accept europlugs, but they all have different standards for grounding.) Presumably it would be something like this: http://www.amazon.com/International-Ada ... 16+adapter

MathWizard
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by MathWizard » Mon Apr 21, 2014 11:38 pm

I just use a 3 to 2 adaptor and then an adaptor for the country I am going to
for cell charger and for laptop.

I don't think that an electric razor will work. I use disposal BIC razors and
shaving cream on trips.

My wife buys a dual voltage curling iron for the trips.

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Epsilon Delta
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by Epsilon Delta » Mon Apr 21, 2014 11:51 pm

This may seem obvious, but does your power supply have a removable cord? If so you can get cord with the figure 8 or trefoil or whatever at one end and an Italian plug at the other.

Professor Emeritus
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by Professor Emeritus » Tue Apr 22, 2014 2:15 am

Epsilon Delta wrote:This may seem obvious, but does your power supply have a removable cord? If so you can get cord with the figure 8 or trefoil or whatever at one end and an Italian plug at the other.
Ive been taking computers to Europe since 1983.

I am in London right now, heading for Italy and then Germany. We have two laptops, three tablets, 2 phones and chargers for a variety of camera and AAA batteries.

For the UK I always use grounded adapters or the removable cord mentioned above. In Italy I have to use adapters since cords with the Italian three prong plug are rare. In Germany I use the European standard plug. The term "Micky Mouse " is used instead of trefoil in many places.

for charging the tablets and batteries you can simply use a set of 110 volt extension cords with a plug adapter. The cords and usb converters will all handle low current 220 volt. Just don't bring anything that runs on only 110 volts that you might plug in by mistake.

wall outlets are much less common in European buildings and so multiplug extension cords are very useful

leod
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by leod » Tue Apr 22, 2014 11:05 am

I break the extra prong on 3 prong laptops to make it work on international travel, have to buy adapter for EU since they have different plug.

Marylander1
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by Marylander1 » Tue Apr 22, 2014 11:13 am

Lenovo sells both 2-prong (grounded) and 3-prong (ungrounded) AC adapters; I have one of each. If you have a Thinkpad, this model is described as "2-pin AC":

http://shop.lenovo.com/SEUILibrary/cont ... #techspecs

-Marylander1

Jack FFR1846
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Re: 3-prong to 2-prong for laptop? & overseas?

Post by Jack FFR1846 » Tue Apr 22, 2014 11:54 am

The adapter will work worldwide if it says "input 100-240Vac" or thereabouts for numbers. (could be 85 or 88 at the low end).

Personally, I would do one test, from experience. Take an ohm meter (or find someone with one) and test both output pins to each input prong. There are some laptop adapters that tie the input ground to the output ground directly. If this happens to be on a 2 prong input, you can inadvertantly tie the hot lead directly to the output and be electrocuted.

How do I know this: I've been a power supply engineer for 29 years. In my home project, I needed a power supply made up of several laptop adapters. To be sure, I did the test with an ohm meter and was surprised to find a direct short from output ground back to input ground. Pulling apart the adapters, I found a full copper PCB for EMI shielding tying the 2 together. The correct way to do this is with 2000 V rated capacitors.

Be sure before plugging the thing in with cut off prongs. There are places in Europe where there is no line and neutral. You are getting line to line, so this would put potentially dangerous voltages onto your laptop.
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