OK, some feel that a isolated system is ok for stand alone use, read the reasoning below (against that thinking)...
On a "stand-alone" (portable) generator serving cord-connected loads only, the frame is permitted to serve as the grounding electrode.
The neutral-to-frame bonding connection serves the same functions as the Grounding Electrode Conductor and Main Bonding Jumper do in a premises wiring system.
Without it, the equipment bonding conductor (EGC) in the load cords will not perform it's intended function.
Check this alert, http://labreq.lanl.gov/labreq/labreq.nsf/LookupDocNum/Alert0005/$File/alert0005.pdf
in particular the last paragraph regarding some Honda generators.
