120 vs 230 volt
@suberband:
"220V is safer??
Thomas, all things being equal, a shock from 240V to ground carries twice the amperage of a shock from 120V to ground. So 120V has the safety advantage. I don't see why 240V is more reliable than 120V."
From a shock standpoint without GFCI/RCD, 240 volts tends to kill more often. Because of ohms law, any electricity flowing through the body will dissipate 4 times the heat at 240 volts than at 120 volts. Burns are more sever, and the higher current increases the odds of going into the "no let go" range.
"The North American system is elegant, I think. 240V, as the potential difference between two 120V legs, is routinely supplied by the power company. Appliances needing less amperage can run on 120V, with less shock hazard than 240V. The problem is availability of 240V within buildings."
In most cases the shock hazard is about the same for North American 240 because most shocks are line to ground giving only 120 volts across the body.
One area where I can think of 240 volts being safer than 120 is during an open neutral event. At 240 volts an open neutral in North America will not cause over voltages, which have been known to cause fires. In countries with 230 volts single phase, that risk is eliminated within the structure's wiring.
.........
400 hertz. While that would result in much smaller transformers, the reactive losses of transmission lines will be far greater. Motors will much smaller as mentioned- but run faster, making a lot of applications require a gear box. From a paper I have, it mentioned 133Hz and other high frequencies back in the day were stalling the development of induction motors. I can copy and paste it here if ok with the site rules.
@suberband:
"220V is safer??
Thomas, all things being equal, a shock from 240V to ground carries twice the amperage of a shock from 120V to ground. So 120V has the safety advantage. I don't see why 240V is more reliable than 120V."
From a shock standpoint without GFCI/RCD, 240 volts tends to kill more often. Because of ohms law, any electricity flowing through the body will dissipate 4 times the heat at 240 volts than at 120 volts. Burns are more sever, and the higher current increases the odds of going into the "no let go" range.
"The North American system is elegant, I think. 240V, as the potential difference between two 120V legs, is routinely supplied by the power company. Appliances needing less amperage can run on 120V, with less shock hazard than 240V. The problem is availability of 240V within buildings."
In most cases the shock hazard is about the same for North American 240 because most shocks are line to ground giving only 120 volts across the body.
One area where I can think of 240 volts being safer than 120 is during an open neutral event. At 240 volts an open neutral in North America will not cause over voltages, which have been known to cause fires. In countries with 230 volts single phase, that risk is eliminated within the structure's wiring.
.........
400 hertz. While that would result in much smaller transformers, the reactive losses of transmission lines will be far greater. Motors will much smaller as mentioned- but run faster, making a lot of applications require a gear box. From a paper I have, it mentioned 133Hz and other high frequencies back in the day were stalling the development of induction motors. I can copy and paste it here if ok with the site rules.