The main reason that Europe uses 230V 50Hz is simply down to the fact that the European systems and US system developed in isolation and in parallel.
Many EU countries used to use 127V + 220V systems, with two hots and a neutral similar to the US, but this was largely abandoned in favour of a single 220V system after WWII (now nominally 230V to split the difference with the old UK 240V standard).
There isn't a particular logic behind why these voltages were selected.
Europe had multiple systems in the early 20th century, so I guess 220V 50Hz was the common denominator and it was also most suitable for using 3000W appliances without cumbersome fittings.
The US may well have standardised on 220-240V 60Hz too, however it didn't have that option as the rollout of electrical appliances was already very well underway and I home owners were unlikely to want to rewire. Europe had a big glitch due to WWII, so had a little more time to think about things and just opted eventually to use 220V for everything. The US standards were generally established quite early on when appliances drawing >1500W were highly unlikely to be encountered.
The safety arguments for 110V are relatively moot as there are generally very few problems with either system provided they're installed and maintained correctly and modern installations are very heavily RCD (GFCI) protected. In Europe, often every circuit has an RCD (GFCI) present.
230V also has a fire safety advantage as a 20amp circuit here can deliver twice the power without overheating where as undersized wiring systems in older homes in the states can sometimes be put under a lot of strain by modern appliances drawing a lot of power (Especially heaters, Air Con etc)
Double insulated everything in Europe was introduced in the 1970s and has been extended to everything. It's nothing to do with the voltage, rather to do with tougher regulations around appliance safety and to mitigate the risk of mechanical damage to cords. Older cords often were single insulated, and even zip cord before that.
Under the current framework of legislation in the EU and CENELEC (European Electrical Standards Body) guidelines, anything above 25V AC requires that. Anything below 25VAC is considered SELV (Safety Extra Low Voltage). So, use power cords if single insulated even used on 110V here would be illegal.
I fell foul of this in a university where we were using a piece of quite old equipment from a US installation that was operating on 110V. We had to replace all the cords and also not use NEMA plugs as they're in breech of Health and Safety regs too as the pins are not sheathed (i.e. you can touch the pins while inserting the plug). So we had to opt for the Euro/IEC 110V industrial plugs!
As for the switch, there's nothing particularly complicated about switches and it would work quite happily on 110-120V without any problems, but at a maximum of 10amps and it should be protected by a 10amp breaker, not by 15amps.
The mechanism and switch arc gap would be designed and tested for 230-250V so, it would be actually over engineered for 110V arcs anyway. There'd possibly be more of an issue with using a US switch on 230V than the other way around.
In the UK or Ireland where it is intended to be installed, it would be connected to a 10amp or 6amp breaker, and absolutely never higher.
An amp is a unit of current, wattage is the unit of power and voltage is potential difference which is comparable to pressure really in a plumbing circuit. All three are interrelated: Watts = Amps x Volts
So, if you decrease the voltage, the amperage goes up accordingly.
1000W at 230V = 4.35Amps
1000W at 120V = 8.34Amps
The current carrying capacity of the wiring, switches and other components is measured in Amps. The voltage is irrelevant. If you exceed the Amp rating on the device at any voltage it will possibly overheat, fail or even catch fire.
Also, please not this type of switch *MUST* be grounded as it's a metal body and should be connected to a back box which is also grounded and interlinked to ensure the screws are not live. Do not install it without a ground as you could give someone a very nasty shock if a wire ever became loose.
Also, if it's a 3-way switch it may have a slightly different layout than you're expecting.
BS (British Standard) light switches are also single pole, so they only have the hot wires present and only switch the hot. If you need to connect hot and neutral, this is not possible with this type of switch and it would not be normal to do so in the wiring system here.
Our neutral's connected to the ground at various points so it can usually be safely assumed to be 0V so there is absolutely no need to switch the neutrals on lights. In most cases, the neutral wouldn't necessarily even enter the switch box at all.
UK light wiring diagrams are linked below. They're possibly quite a bit different to the way it's done in the US.
Overall, I'd say while this is a perfectly good switch in every way, you're better off using a local switch that fits into your own system. There must be some chrome US-style switches you could use instead?
Using a British switch is just going to mean complications with breaker ratings, sourcing boxes and if it breaks you'll have to source a new British switch as US ones won't fit the BS-type boxes.
All of these systems are very good, but you are better not to take bits from one system and mix them with bits from another as you add a lot of complications that the designers of those systems did not envisage. They're called "systems" for a reason![this post was last edited: 1/11/2015-19:22]
http://www.ultimatehandyman.co.uk/how-to/light-fitting/light-wiring-diagrams
Thought most 230+v in europe were DC when I was there decades ago? If there using AC I don't get why it needs to be over 120volts? is it the cycles 60 vs 50?
