Welcome!
You are our first member from Switzerland. To answer your question: Yes there is a higher single phase voltage, 240V (60Hz). Unlike the European 230/400V system the 240V is in the USA 120/240V. It is usually called a center tapped single phase system. To get 240V single phase you simply connect the load between the two "hot" ("phase") wires. Available in almost all American homes.
For industrial use there is also a 277/480V system. Works just like our 230/400V system. (Note: Canada uses 347/600V instead)
It can be noted that apart from the frequency, the American 240V (almost) falls within the European 230V specifications. (Min 220V max 254V compared to 207-253V)
