Wiring triviata

>>Also when you(American and other 110V countries) people say you use 
>>220V where do you get it from?
>In the U.S., homes are wired with 220V center taped.
	MOST homes.  High 99%.  Occaisionally, esp in older areas of a city,
	110 only will be encountered.

>This is an average voltage, it varies from 220 to 240 depending on the location
>The center tap is grounded. Most of the house wiring is from one side
>or the other to ground.
	To be picky, the center tap is connected to neutral/return.  Power Line
	Ground is a separate entity (and separate, again, from RF/coiling
	ground.)  Power Line ground should be connected to power line neutral
	at one point only, etc, etc...

>High current devices (heaters of various sorts) are connected to the full
>220V. It's single phase.
	Usually.  One occaisonally finds two phases of a three phase wye used.
	This gives 110ish to neutral but 208 'cross phase' to the two hot lines.