Hi can someone explain to me what the neutral wire connection physically looks like in a 3phase generator?

 

Ummm.. It will be white. (in the US at least)

But seriously, depends on the configuration.

Google: 3phase WYE neutral and 3phase DELTA neutral

That will show you where the neutrals are used, when used, in the different configurations.

 

Hello,

Here is the definition found in the wiki:
http://en.wikipedia.org/wiki/Neutral_wire

Bertus