I did some thinking, more thinking, talked with some electricians and the guy who is manufacturing the heating elements for me and we decided to lower them to 4500W. I also read the great http://www.theelectricbrewery.com/ and exchanged some email with Kal.
Here in Brazil, altough the grid should be 220V, it is rated as so, sometimes we get 232V, 240V and this would certainly over used my home installation with 5500W elements.
It will take longer, but it will be WAY SAFER and at the end, I am not in a rush anyway, it is a hobby and time is not money here!
The 4500W elements should exceed my burner anyway, so, it has all the odds to be better then what I do today.
I also could easily add Kal´s 50A control panel to my setup in the future.
Tks the forum, as soon as I get the elements and test them, I´ll post the results.