"1) the change of a fire due to overload is much lower. (its more difficult to overload a 220V circuit)"
Thats what circuit breakers are for. They disconnect long before the wire itself is hot enough to start a fire. Second because 240 volt circuits can carry twice the power, they will run twice as many lights and/or receptacles. No electrician will limit a 3,600 watt residential circuit to 1,800. Also code requires 3va per foot minimum when determining how many general use circuits, so a 2,000sqft home could either be wired with 4 120 volt 15 amp circuits, 3 120 volt 20amp circuits OR 2 240 volt 15 amp circuits...
"2) The shock itself is dangerous (or twice dangerous), but safety devices, like circuit breakers, DR, etc have a minimal (but existent) change to go off faster than 110V, exactly because of the higher voltage. So ok, the shock itself is worse, but it may last a fraction of second less. and it can be the difference between life and death."
Typical shock currents are in the milli-amp range as well as fatal levels. 1 amp is considered very lethal. To trip any residential breaker you need to go above the handle rating, and to trip the breaker instantaneously you need at least 10 to 20x the handle rating. Which means if a person being shocked is passing 18 amps the breaker will probably never open, they would need to pass 25 amps to trip a 15 amp breaker in 60-90 seconds, and 150 to 300 amps to trip the breaker in a fraction of a second.
150 to 300amps for a fraction of a second passing through a person's body would cause severe, fatal burns. There is a graph I can post which shows the duration of shock vs magnitude the body can tolerate to a certain point.
Also thank you for those links, Foraloysius.
