The rotor shall meet electrical and

The rotor shall meet electrical and mechanical balance before and after the over speed test, which must be at 125% of rated speed with the highest practical design rated temperature rise. Rotor bearings shall be designed to withstand the stresses resulting from acceleration from zero to rated speed within typical starting times of 2 minutes, with immediate application of full load at rated speed. For sleeve bearings, nominal rotor end float shall be specified in the supplier data sheets. The rotor magnetic center marking shall be permanently scribed around the generator shaft, at the drive end. If thrust bearings are provided, magnetic center markings do not apply. The magnetic center marking shall always be readily visible from the exterior of the stator housing. Minimum end float on either side of magnetic center will be 4.8 mm (0.1875 inches). The generator rotor shall neither exert an end thrust nor be required to accept one. If end thrust results because of magnetic centering forces, these shall be defined. Moments of inertia shall be provided in lb-ft2 and kgm2 per attachment 2, Generator Data Sheet. Generators shall be designed to have low breakaway torque as starting power is limited in capacity. Calculated breakaway torques must be provided on Generator Outline Drawing with first set of supplier drawings for Mars Generators or smaller.