balanced power


Hi, could anyone explain to me in short what balanced power means? This is a term that is applied to isolation transformers. I'm using isolation transformers too (I live btw in The Netherlands) but I'm not using ground. Is that what "balanced" means: using a ground? What are the benefits and drawback of balanced power? Thank you in advance.

Chris
dazzdax
Folks - That was really helpful. I've wondered myself what "balanced power" meant. Now I at least have a clue.
Thanks. Chris - good question!
In the schemes I've seen at the Equi=tech website I encounter one stable element and that is: ground. So for a proper balanced power a ground is necessary. What to do without a ground? Then balanced power (and common mode rejection) is not possible? I don't understand it completely. It is also confusing when you read that the Wavac isolation transformer (made by Denken Seiki of Japan) doesn't need ground to achieve full "common mode rejection". How could this be possible? Once more: it is confusing!

Chris