Is this for co generation or standby? What are the grounding requirements for your system?
Yes it is typical and recommended for most utility generators. What you need to determine is fault current values (Phase to ground) that are acceptable for your system. As a rough rule of thumb, it is recommended that an ohm value be used in that the phase to ground current is around the phase to phase value during a fault.
If the system you are feeding is a high resistance grounded system that can run on a grounded phase, (as with critical process plants), the ohm value should permit a current to flow about that of the capacitive charging current (to ground) of the phase conductors.