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Comment by usr1106 | Hacker News Reader

Is there any data about how many people die in electricity related accidents? 230 V sounds like a dangerous voltage to touch. On the other hand I read a long time ago 120 V causes way more home fires because of higher currents.

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North/Central America is kind of the outlier running on 100-ish volts. Most of the rest of the world runs on 200-ish[0]. Electricity-related deaths aren't exactly common worldwide. And yes, I can see 100ish causing more fires — given dissipated power scales with current squared, my 2kW tea kettle can't possibly be safe in the US.

0. https://en.wikipedia.org/wiki/Mains_electricity_by_country

To be fair, pages like the one you link only talk about the official standards, which mean very, very little in most of the world.

I wouldn't assume anything about voltage in much of South America / Africa / Asia. You're going to get a frankenstein NEMA-Schuko-Chinese power outlet that will give you some amount of power for some amount of hours in the day, for a definition of 'some' that no one will be able to specify for you with any great precision and that will vary from town to town.

> You're going to get a frankenstein NEMA-Schuko-Chinese power outlet

They are very practical, as they accept any plug

They are also more dangerous, as they don't have a good grip on the plug, and usually don't have shutters.

Anecdotally, 230V is safer than 120. 120V will put you into fibrillation, whereas 230V will stop it.

Fires are generally caused by loose connections with higher resistance getting hot and catching something nearby on fire. The British connection in OP is much less likely to have a loose connection.

This is the first time I hear this and I doubt it’s true.

Typically the distinction is made between 50 and 60 Hertz, where 60Hz is typically considered safer(though I’m not sure if this is even true).

I am an electrician hence why I am curious.

I was told by the supervisor of my high voltage lab as part of the "one hand in your pocket" speech. It's also not hard to find similar statements via Google. Neither are definitive sources.

Ok, well it’s wrong. 230V is more dangerous than 110V, all else being equal.

It's not wrong. 110V is more likely to cause fibrillation. Fibrillation isn't the only way AC can kill you so which is more dangerous is more debatable.

The problem is that the risk of death is so low for both that people's perceptions are skewed. Everybody has been shocked by their household voltage a bunch of times, so they think it's no big deal. Until it isn't.

Yet you can’t provide any source for this claim?

"Its the Volts that Jolts and the Mills (milliamps) that kills"

In my first aid class in a 230V country we were taught: Someone who got an electric shock always needs to visit the emergency room, even if they seem to be fine. Reason: fibrillation has to be ruled out or stopped.

So 230V stops it does not sound right. Whether there is any difference in probability I have no clue.

> On the other hand I read a long time ago 120 V causes way more home fires because of higher currents.

[citation needed]

All domestic mains plugs found in typical residential circuits all over the planet are ≤20A:

* https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#Com...

The vast majority of 120V plugs are 15A; if you want 20A it's actually a special case:

* https://en.wikipedia.org/wiki/NEMA_connector#Nomenclature

So there are no "higher currents" used. If you need more power then a higher-voltage NEMA 6 plug, or a two-phase NEMA 14, socket is typically used.

Americans have to worry about chaining power strips, or overloading them with the Christmas lights.

That's much less of a concern in 230V countries.

For a 1kw appliance, with 220v it should be 48 ohms, but for 110v it needs to be only 12 ohms. So if you have a bad wire or connector, which has say 5ohms resistance, more of the voltage will drop across it. At 220v it will have 21v across it and be heated by 88W but at 110 it will actually have 32v across it and be heated at 204W. That could easily be the difference between a fire starting and not.

I do remember reading somewhere that for all the vaunted safety features of the plugs, etc, more people do in fact die in Europe and the UK than in the US from contact with the mains, precisely because of the 240V potential. (Definitely anecdata, would be curious about the hard numbers too!)

Of course, the trade off is much faster kettles. How many lives is faster tea worth? For the British, clearly the answer is 'yes'. :P

In the UK we use both 240V and 110V (nominal). Our supply is at 240V. Our appliances are pretty safe out of the box - several standards.

We also utilise 110V devices but that requires a step down transformer. I have one. My big hammer drill runs on 110V.

Fire is not caused by electric current. Fire requires a source of ignition and that's not EMF.

More details please.

> Fire is not caused by electric current. Fire requires a source of ignition and that's not EMF.

All electrical cable/wire is rated for so many amps and a certain temperature: if you mismatch the breaker and the cable ratings then you could allow too much current through, and because of I^2 resistance, a fire could happen.

Do a search for "Ampacity Chart".

* https://en.wikipedia.org/wiki/Ampacity

If you're claiming the UK uses 110V, then you must also include that it uses 415V.

Both of these are only used outside domestic settings. (Until recently, 415V for a car charger is becoming more common)

110V is regularly used via transformers, generally for safety - 110V doesn't kick you as much as 240V. Perhaps I didn't emphasise that 110V is not grid delivered here.

I have a 110V transformer and a 110V rated SDS hammer drill. The idea is that if I manage to hit an electrical cable then I will probably not die, with luck.

We also have three phase which I think is normal in the US, for example and is why ethernet over power line is a bit fraught.

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