Schambo1

Hi, We are moving to the States in the next couple of weeks. Can anyone please advise whether my UK lamps will work in the USA? I am a bit confused about the electrical situation.....

Lion in Winter

Not unless you put converters on all of them, no. Unless they are already dual voltage - laptops and phone chargers usually are (and it will say so on the unit), lamps not so much.

http://www.amazon.co.uk/Step-voltage...079648-6235041

mikelincs

USA is only 120 volts, so bulbs from the UK will not work, also they will need new plugs as the US sockets are very different. I would suggest that for things like lamps, unless they are of special significance or value would be best leaving in the UK and buying new ones. Bulbs are from what I can see, all ES fittings, so if you have the bayonet type in your lamp you may have difficulty in getting new ones.

Lion in Winter

Which was probably a better reply than mine.

Yorkieabroad

We have a few that we brought from Singapore ( also 240v) because they were antiques/unique/unusual. Just switching the plugs allowed them to work, but they were very dim - an electrician probably wouldn't be impressed! I rewired a few table lamps to US standards with some fairly cheap kits from Home Depot - cheap, quick and easy.

Michael

220v UK Light bulbs consume 1/4th the power of US 110v light bulbs of the same wattage when used on 110v lines and are therefore burn very dim. That is because the resistance (the filament) of the light bulb remains the same whether using 110v or 220v but when using 110v both the voltage and the current drops in half equaling 1/4th the power consumed.

Use the following calculator to see this. First plug in the UK voltage (220v) of the line and the wattage (power) of the light bulb (100 watts) and press calculate and the resistance will be 484 ohms (the resistance of the filament). Then clear the calculator and plug in the US voltage (110v) and the resistance (484 ohms) and press calculate and the wattage (power) will equal 25 watts.

http://www.onlineconversion.com/ohms_law.htm

If you try to take US light bulbs to the UK, they will consume 4x times the power and burn very brightly for about 2 seconds before overheating the filament and burning out. So a 100 watt US light bulb will produce 400 watts of power in the UK for a few seconds before burning out.

So if you want UK lamps to burn at the proper brightness in the US, quadruple the wattage of the light bulbs if available (may be possible for chandeliers by using 60w bulbs instead of 15w bulbs) before coming to the US or replace them with US bulbs of the same wattage after arrival if the sockets are the same.

Any appliance that uses a filament (heating element) should work the same such as toasters, tea pots, etc. heating only to about 1/4th their power when used with 110v.

Fluorescent bulbs do not have filaments (a fixed resistance) so the formula doesn't work the same and may not have enough voltage to be excited to even turn on when using 110v. However if they do turn on (highly unlikely), they should burn the same brightness in both countries.

Everything with a motor (except products that run on DC voltage through an adaptor such a laptops, electric razors, etc.) have different problems. Not only will they consume less power when using 110v which can cause drag and possibly overheating but they also try to spin according to the frequency of the line. Since the US line frequency is 60 Hz (60 cycle per second) and the UK frequency is 50 Hz, a UK motor will tend to try to run faster in the US with on load but may miss cycles or even stop due to the low power under normal load.

Mr Weeze

I haven't thought about this very much, but if I change the plug and the bulbs on a lamp, will it work? I tend to avoid playing with electrics, so I haven't bothered thinking about this, but I'm struggling to think what difference the internal wiring in the lamp would really make. Is wiring specifically rated to a 110 vs. 220/240V, given the very low electrical resistance you would hope it has?

Michael

American 100 watt bulbs draws 2x the current as UK 100 watt bulbs. Current is what causes heat. UK lamps generally have bigger cords than American lamps which should indicate bigger wires in the cord. As long as the cord is at least the same size as a typical American lamp cord (usually very small), there shouldn't be any problem. It doesn't take a very large wire to pass 0.9 amps of current (110v at 100 w). Why UK cords are so large, I do not know except possibly to protect people from accidently cutting the cord or the cat chewing through it. You can also check the size of the wires of a UK cord compared to a US cord by removing the plug to make sure that the wires in the UK cord are at least as big as an American cord using the same wattage. Even American toasters (about 600 watts) or about 5.5 amps or toaster ovens (about 1200 watts) or about 11 amps don't use a very large cord.

The differences between UK and US cords may be that UK cords may contain solid wires which are slightly better for conductivity than the stranded wires normally used in the US but are less flexible. Usually only for internal wiring of a house or very large appliances are solid wires used in the US. A lamp using a 100w-1000w appliances with a 5' cable only requires a 30 gauge wire (0.25 mm) or smaller which is very small wire but as the cable gets longer, the wire needed is larger (lower gauge) due to the increased resistance of the wire as the cable gets longer. UK wires should be able to be smaller for the same wattage and distance.

http://phd.boschsecurity.com/wiregage_cal.cfm

Jerseygirl

Maybe it's because UK cables house 3 wires not 2 as in the US...positive, negative and earth/ground.

Michael

Lamps and small appliances normally have the voltages isolated so normally there isn't a need a ground unless you run water on it. In a lamp, the only place you can normally get a shock is by putting your finger in the socket. Even then to create a serious shock, you have to run current through your body (through the heart) to ground so if you are standing on a carpet, usually the shock is not serious since the shock is from one part of the finger to the other part of the finger. Even if a cat chews through a cord, the shock is normally from the lower jaw to the upper jaw and not through the body.

With higher voltages (220v), it is easier to get a serious shock since it is easier to find a ground on the other side of the body. Also it is normally easier to pull away from a 110v shock than a 220v shock. The biggest danger is in the kitchen or bathroom where the hot wire shorts to a part that you can touch due to water and the appliance is only two wire or the GFCI protector is not installed for three wire plugs (although the breaker can possibly kick if enough current is drawn). Apparently manufacturers believe that two wire toasters, coffee makers, blenders, and hair dryers don't present a significant danger due to the plastic enclosures and the low voltages in the US. However I wouldn't want to throw any of those into a sink full of water while turned on and my hand was in the water.

According to the Navy, 40v is enough to kill someone under the right conditions on a ship due to the large amount of metal (ground) and the moisture in the air. The person may have to be barefoot on a metal deck, touch a hot wire, and the moisture in the air may needs to be high to kill him but it claimed to be possible at 40v

scrubbedexpat097

So to make a long story short with all these awesome technical answers I would say, just buy lamps when you get here

Michael

To put it simply, I don't see any reason that UK lamps cannot be used in the US as long as you can find US light bulbs of the desired wattage with the same type of socket. However, incandescent light bulbs will be completely phased out to purchase for lamps by 2014 in the US.

steveq

CURRENT kills. If 40V will drive 20mA through the heart, then it MAY kill you. If you're sick then as little as 4mA may kill you. There have been reports of death caused by a PP3 9V battery in the literature.

The guy that was instrumental in the introduction of RCDs died a few months back, and the limits for the currents were developed empirically - by experimenting on himself.

Died at a ripe old age too.

paddingtongreen

Think of a pipe, with pressure being the voltage and the fluid being the current. If you halve the pressure, less fluid will flow, halve the voltage and less current will flow. If you reduce the pressure, you need a bigger pipe to get the same amount of fluid through. The filament in a 100 volt fixture is a bigger pipe than a 220 volt fixture.

scrubbedexpat099

So its like the Internet?