Crane Duty Motors

MARATHON Electric introduces VD series motors tailor made for inverter drives having enhanced dielectric strength and adequate thermal margin suitable for variable speed application. PWM technology involving high switching frequency IGBT drive has enabled AC induction motors to be operated as variable speed drives. However, there had been a documented increase of premature winding failure for standard general purpose motors when operated with inverter drives. High and steep front voltage spikes (dV/dT) produced by latest generation IGBT drives associated with the phenomenon of voltage wave reflection due to longer cable length imposes stress on the motor winding resulting rapid ageing and deterioration of insulation system.