Bus-bar fort Series connection?

You normally would not use a bus bar setup to wire in series... It is + to - and the second connection is also + to -... Then the only two leads left (first and third panels) - and + leads are 3x the Vmp (and Voc) of the single panels. (more or less, just like sliding three D Cell batteries end to end in a flashlight.

Bus Bars are generally used when you need to make a bunch of connections to one point (such as + and - terminals of your battery bank).

If you would like to get an idea about how to do DIY and other Solar Connections, 2manytoys has a great website (1/2 down on the right) detailing his long solar voyage:

http://2manytoyz.com/

If you still are unclear, please ask more questions. There are many different types of solar panels out there (J-box plus screw terminals, configurable J-Boxes, leaded panels with MC-4 or other connectors, etc.). It is possible that I did not understand your question.

-Bill