TRANSFORMERS AND TRANSFORMER VAULTS 70-443

and the generator should operate to failure to prevent a greater hazard to persons, the overload sensing device(s) shall be permitted to be connected to an annunciator or alarm supervised by authorized personnel instead of interrupting the generator circuit. 445-5. Ampacity of Conductors. The ampacity of the phase conductors from the generator terminals to the first overcurrent device shall not be less than 115 percent of the nameplate current rating of the generator. It shall be permitted to size the neutral conductors in accordance with Section 220-22. Conductors that must carry ground-fault currents shall not be smaller than required by Section 250-23(b). Exception No. 1: Where the design and operation of the generator prevent overloading, the ampacity of the conductors shall not be less than 100 percent of the nameplate current rating of the generator. Exception No. 2: Where the generator manufacturer's leads are connected directly to an overcurrent device that is an integral part of the generator set assembly. 445-6. Protection of Live Parts. Live parts of generators operated at more than 50 volts to ground shall not be exposed to accidental contact where accessible to unqualified persons. 445-7. Guards for Attendants. Where necessary for the safety of attendants, the requirements of Section 430-133 shall apply. 445-8. Bushings. Where wires pass through an opening in an enclosure, conduit box, or barrier, a bushing shall be used to protect the conductors from the edges of an opening having sharp edges. The bushing shall have smooth, well-rounded surfaces where it may be in contact with the conductors. If used where oils, grease, or other contaminants may be present, the bushing shall be made of a material not deleteriously affected.