The original question appeared to be a compliance issue. I believe IWIRE is correct. The generator may be connected to the premisis wiring with either a 3 or 4 pole transfer switch.
If a 3-P switch is installed the NEC does not allow the generator neutral to be bonded at the gen or transfer sw.(XO). Additionally the non-current carrying metal parts (frame etc.)must be grounded per section 6 (VI) of article 250 by a method listed in 250.118.
If a 4-P sw. is used the generator is a seperately derived system and grounding and bonding are required per. 250.20 and 250.30 to mention a few.
Either way all eq. grounding eventually ends up at the premisesis supply main bonding jumper. (Generally)
A ground fault with the 3-P sw. may raise the voltage to ground through the Eq. Grounding Conductor.
A ground fault with the 4-P sw. may seek the main Bond through a connection at the transfer sw as well as the Neutral at the gen. Depends how the Code is applied.
No doubt an open neutral is trouble.
Back feed (so to say) at the gen during maintenance addressed in section 445.18.
I liked the idea about additional signage at the MDP.
