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Originally posted by sigcrazy7:


In the U.S., we chose to go with safety over cost, with 240v available when absolutely needed, like in high resistance loads or electric motor loads. It's hard enough to keep your kids from getting killed from sticking things in a receptacle at 120v. Imagine how much more dangerous it would be for them to come at 240v receptacles with a fork.

quote:

Originally posted by sigcrazy7:
In the U.S., we chose to go with safety over cost, with 240v available when absolutely needed, like in high resistance high current loads or electric motor loads. It's hard enough to keep your kids from getting killed from sticking things in a receptacle at 120v. Imagine how much more dangerous it would be for them to come at 240v receptacles with a fork.

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Originally posted by PASig:

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Originally posted by sigcrazy7:


In the U.S., we chose to go with safety over cost, with 240v available when absolutely needed, like in high resistance loads or electric motor loads. It's hard enough to keep your kids from getting killed from sticking things in a receptacle at 120v. Imagine how much more dangerous it would be for them to come at 240v receptacles with a fork.

I don't think that is the case though.

Euro 230V household power is actually safer as it's lower amperage than ours. In all my reading about it, it appears that this is the case and Europe seems to also have far fewer electrical fires than we do.

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Originally posted by PASig:

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Originally posted by sigcrazy7:


In the U.S., we chose to go with safety over cost, with 240v available when absolutely needed, like in high resistance loads or electric motor loads. It's hard enough to keep your kids from getting killed from sticking things in a receptacle at 120v. Imagine how much more dangerous it would be for them to come at 240v receptacles with a fork.

I don't think that is the case though.

Euro 230V household power is actually safer as it's lower amperage than ours. In all my reading about it, it appears that this is the case and Europe seems to also have far fewer electrical fires than we do.

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Originally posted by Rey HRH:

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Originally posted by Lefty Sig:
Yep. The US chose 110/120V to limit electrocution risk, although it is still high enough to kill. But we do have the two hot center neutral system so we can get 240V for things that need it (ovens, dryers, water heaters).

Europe, China, Korea, and many other places went 240V to minimize the wire size/weight/cost. Japan is 100V similar to the US.

The idea of less electricution doesn't pass. I forget the actual number that was drummed into me going through shipyard electronics training but it's the current that kills you, not the volts and the number is very low.

Also, statistics say more people are killed by 110 v because people get complacent.

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Originally posted by sigcrazy7:

Have there been any studies as to the actual reason why there are less fires? Is it really the 230v, are there other factors? Although it is amps that kills, 13a is above the thresh hold of lethality. Therefore, avoiding a shock is more important than the amplitude of the shock, if both options are above the level of being lethal. As for less fires, I don't see how amperage plays into this. Yes, they run half the current, but they do it on wire that is half the size. Therefore, they have about the same impedance, so would have the same amount of fires.

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Originally posted by Balzé Halzé:

Less amperage for everyday appliance equals less heat buildup in the wires throughout the house. Less heat in the wires, less potential for fires. You get the idea.

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Originally posted by sigcrazy7:

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Originally posted by PASig:

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Originally posted by sigcrazy7:


In the U.S., we chose to go with safety over cost, with 240v available when absolutely needed, like in high resistance loads or electric motor loads. It's hard enough to keep your kids from getting killed from sticking things in a receptacle at 120v. Imagine how much more dangerous it would be for them to come at 240v receptacles with a fork.

I don't think that is the case though.

Euro 230V household power is actually safer as it's lower amperage than ours. In all my reading about it, it appears that this is the case and Europe seems to also have far fewer electrical fires than we do.

Have there been any studies as to the actual reason why there are less fires or electrocutions? Is it really the 230v, or are there other factors? Although it is amps that kills, 13a is above the thresh hold of lethality. Therefore, avoiding a shock is more important than the amplitude of the shock, if both options are above the level of being lethal. As for less fires, I don't see how amperage plays into this. Yes, they run half the current, but they do it on wire that is half the size. Therefore, they have about the same impedance, so would have the same amount of fires.

All I'm saying is there could be other factors besides just the voltage of the system. The U.S. is one of the only places in the world that allows wire nuts. Could it be that more fires come from improper splices than from heat generated on the wires themselves? The U.S. uses more NM cable behind wallboard than many places in Europe, where in Europe, MC/conduit and plaster is a far more common form of building material. The U.S. was one of the first nations to electrify, so we have a higher incidence of legacy wiring, like K-T, than other countries. Could there be code reasons to attribute the lower shocks and fires? For example, some parts of Europe don't really allow power in a bathroom, or the power is so low that it will only run an electric razor. Perhaps it's that we have a far more permissive culture that tolerates more DIY work, so there is a much higher incidence of improper work here than in more heavily regulated Europe? Lastly, I'd love to know how many house fires we have vs Europe if you were to eliminate those caused by Zinsco panels or that 1960s/1970s era AL wire. I'd bet those panels and wiring alone are the source of many of our fires.

I'm not saying that any of these factors are the reason for more fires and shocks here than Europe. I am saying that I'd love to see a study that controlled for these other factors to give us a real number of the advantages of 230v verses 110v, especially given how expensive it would be to change. I don't think, however, that we can make a prima facia conclusion that voltage alone is the reason.

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Originally posted by Rey HRH:

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Originally posted by Lefty Sig:
Yep. The US chose 110/120V to limit electrocution risk, although it is still high enough to kill. But we do have the two hot center neutral system so we can get 240V for things that need it (ovens, dryers, water heaters).

Europe, China, Korea, and many other places went 240V to minimize the wire size/weight/cost. Japan is 100V similar to the US.

The idea of less electricution doesn't pass. I forget the actual number that was drummed into me going through shipyard electronics training but it's the current that kills you, not the volts and the number is very low.

Also, statistics say more people are killed by 110 v because people get complacent.

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Originally posted by maladat:
In the UK, all the plugs (not outlets, the actual plugs that you plug into the outlets) have to have fuses/circuit breakers in them. I imagine that alone is a pretty significant contributor to reduced electrical fires.

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Originally posted by sigcrazy7:

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Originally posted by maladat:
In the UK, all the plugs (not outlets, the actual plugs that you plug into the outlets) have to have fuses/circuit breakers in them. I imagine that alone is a pretty significant contributor to reduced electrical fires.

Great point. Here in the U.S., our receptacles suck. We protect a 12ga wire at 20a to the receptacle, but then allow a 100ft 16ga extension cord to plug into it with no over current protection. Every extension cord should be fused for its rated capacity. Our plug design should also prevent the prongs from being energized until they are fully inserted, but they don't. The design definitely needs and update.

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Originally posted by mrw:
Wire conductor size (cross section area) of a branch circuit is determined by the branch circuit breaker or fuse amp rating up stream of the conductor. This applies the same in Europe and the USA. Voltage does not have any bearing on the size of the wire just the insulation type on the wire.

In my experience Europe 230V branch distribution protection is by a 16A circuit breaker. In the USA it is 15A circuit breaker. So the wire size would be the same even though one is 230V and the other is 120V. No savings there.

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Originally posted by mrw:
Wire conductor size (cross section area) of a branch circuit is determined by the branch circuit breaker or fuse amp rating up stream of the conductor. This applies the same in Europe and the USA. Voltage does not have any bearing on the size of the wire just the insulation type on the wire.

In my experience Europe 230V branch distribution protection is by a 16A circuit breaker. In the USA it is 15A circuit breaker. So the wire size would be the same even though one is 230V and the other is 120V. No savings there.

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Originally posted by maladat:

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Originally posted by Rey HRH:

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Originally posted by Lefty Sig:
Yep. The US chose 110/120V to limit electrocution risk, although it is still high enough to kill. But we do have the two hot center neutral system so we can get 240V for things that need it (ovens, dryers, water heaters).

Europe, China, Korea, and many other places went 240V to minimize the wire size/weight/cost. Japan is 100V similar to the US.

The idea of less electricution doesn't pass. I forget the actual number that was drummed into me going through shipyard electronics training but it's the current that kills you, not the volts and the number is very low.

Also, statistics say more people are killed by 110 v because people get complacent.

Sure, it only takes a tiny amount of current across your heart to kill you.

However, your skin has a pretty high resistance. Remember V = I * R (volts = current * resistance). Unless you stick wires through your skin into your wet, salty, very conductive insides, it takes a lot of voltage to push enough current through your skin to kill you.

This is why you can touch the terminals on a car battery, which can supply 500 amps for a few seconds, without turning into a cartoon glowing skeleton. Sure, a car battery can supply 500 amps into a dead short. Into the resistance of your skin, the car battery's 12 volts (actually, should be more like 14 volts) can't push enough current to hurt you.

The current limit is still important, though. It's why stun guns don't (usually) kill people. They may put out 100,000 volts or whatever, but they can only supply an absolutely minuscule current. There's enough voltage to push enough current to kill you, but the current supply just isn't there for it to actually do so.

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This is good for the high current stuff but all the integrated circuits would need a step down to 5 volts (or whatever they needed) and the only practical way to do that was with a power resistor, which means more current, more heat, added weight, etc.

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Originally posted by stoic-one:

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This is good for the high current stuff but all the integrated circuits would need a step down to 5 volts (or whatever they needed) and the only practical way to do that was with a power resistor, which means more current, more heat, added weight, etc.

Not knowing how long ago this was, but there are a lot of ways (transistor/IC) to "step down" DC which doesn't consume a lot of power. Now going up in DC voltage is another animal, usually involving modulation to AC...

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In the UK, all the plugs (not outlets, the actual plugs that you plug into the outlets) have to have fuses/circuit breakers in them. I imagine that alone is a pretty significant contributor to reduced electrical fires