I kind of think that article was written by the gentleman who wrote the article about the C-14 in the 'it is now 10 years old' or similar thread :-) He misses on both the reason we (US) have a true neutral leg, giving us 115 volts (volts AC, VAC) and 230 VAC all in one circuit.
The power grid was invented in the US and it was a mess for a long time. Edison insisted on using DC because he could use Ohm's Law and figure out how it would work with various devices. He could not figure out how to deal with AC as that takes calculus and there were no simple solutions (for all of his fame and worship in the US and perhaps the world, T.A. Edison was not 'the brightest bulb in the chandelier', nor did he interact with others either very well or at all) until a German named Steinmetz came along and introduced the concept of 'operators' which DID replace the simple parts of DC circuit calculation (this is the part about not working with others; Steinmetz gave Edison what he needed to use AC but Edison would not listen).
So when the very first power plant for public supply went in in NYC, it was DC and a strange voltage (I do not remember but it was not the nominal 120 volt). Edison envisioned a power plant every two miles spread in a true grid (where we get the name used today for electrical distribution, 'the grid') all over the US of A. Unimaginable now but then, well, it did not see so bad. But electric motors using DC require brushes to commutate them, and that was a mess too along with a world of hurt regarding short life, spark generation, the occasional fire, poor performance, poor efficiency and greatly varying speed depending on load. Even Edison saw this was a problem. Enter Mr. Nicola Tesla, a genius, a gifted man, a true visionary and a little bit of a whack- job (well, maybe a medium level whack- job) but as a package, an excellent place to start :-) He works for Edison and suggests that he can make an electric motor with NO commutation! Edison tells Tesla that he will give him $50,000 if he can do so and Tesla proceeds to do exactly that by producing poly-phase AC and the induction motor. Fantastic! Tesla asks for his money, to which Edison tells Tesla that he, Tesla, does not understand the American sense of humor and there really is not any money coming Tesla's way. Did I mention that Edison was kind of a schmuck too? Anyway, that sealed Edison's fate right there because Tesla quit (no matter really) but then went to work for..... George Westinghouse (a disaster for Edison).
But while all of this is going on, the electrification of the northeast US is also happening, with the worst of all possible standards, even worse than DC.... no standard at all. All different voltages, currents and methods of delivery and usage, no rules, no convention just electrical devices failing all over the place and fires waiting for the right time to start. And then Westinghouse's AC induction motors show up and power plants to power them.... but at all different voltages and frequencies. Not too bad when buying one or five light bulbs but a real PITA if trying to run a refrigerator and your block in NYC does not have the right power for the one you bought.
Finally, Westinghouse sets up large scale dynamos at Niagara Falls (and who does not like 'free' power?) and successfully sends that power to Buffalo, NY, about 20 miles away. That was the death knell for DC, Edison's fall would come shortly thereafter (although he remained a wealthy man while Tesla died penniless after finally having converting the rest of his chips into full- blown whack- jobocity). Westinghouse started powering up the US and chose 60 cycles and I do not know why that was. Not sure that anyone does. Britain, Italy and Germany were all there at the fore- front of the electrification of their own countries around the same time. Italy never really got beyond a good start, Britain had several 'movers and shakers' but included Joseph Lucas, The Prince of Darkness who invented the automobile switch with three settings: dim, flicker and off.
(just for you Mike!). And of course, Germany had Bosch and especially, Siemens, who would go on to set the standard for Germany as well, I suspect, for most if not all of Western Europe. Japan was just a little later but late enough to find other parts of the world well underway in electrification. They must have been confused as to which way to go so they bought some generators from both AEG and GE (General Electric; originally the Edison General Electric Co. but remember the part about Edison being a putz, well that is what the board of EGE thought too so they tossed him and his name), put them in the south and north of Japan respectively and then found out when they twisted the wires together where the two systems met, the wire nuts kept turning white and falling off. A real head- scratcher, that one was....
Not sure why it happened, but I believe we maintain 115 VAC (nominal) for consumer devices for safety. We are also pretty cavalier with our plugs and so forth- it is easy to get a shock using American electrical gear (another tidbit: normally, the solid part of an electrical connector is made part of the structure, machine, whatever, and the spring loaded part is part of the cord so when it wears out, you do not have to replace the house or factory but just the cord. Edison thought of that and invented our ubiquitous two- prong (Easy Boys! they added a third one later) electrical plug.... with the rigid parts sticking out of the wall, and the spring loaded contacts in the device! Fortunately that one did not get out into the public, eh?) while you Brits are over the top regarding plug safety (the insulated prongs, the shutters on the wall outlet, although we have them too now and so forth). Then again, you have more voltage waiting to bite you.
As to the frequency of our two systems, I do not know and suspect that perhaps there is not really a reason, it just worked out that way. Someone picked, and that choice spread.
And now for the part everyone has been waiting for......
And finally, the answer to the question: what could possibly go wrong?
Brian
interesting read on why the difference, blame Thomas Edison lol
http://thednetworks.com/2012/06/10/why-does-ukusa-use-110120v-and-others-use-220240v/