Generation and distribution system grounding.

The neutral of each grounded generation and distribution system must: (a) Be grounded at the generator switchboard, except the neutral of an emergency power generation system must be grounded with: (1) No direct ground connection at the emergency switchboard; (2) The neutral bus permanently connected to the neutral bus on the main switchboard; and (3) No switch, circuit breaker, or fuse in the neutral conductor of the bus-tie feeder connecting the emergency switchboard to the main switchboard; and (b) Have the ground connection accessible for checking the insulation resistance of the generator to ground before the generator is connected to the bus.