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.