Nidec Motor Corporation has introduced a line of totally enclosed fan cooled Corro-Duty Vertical Holloshaft inverter duty motors. The U.S. Motors brand motors are cast iron and designed with full Class H insulating materials to withstand the steep-wave-front voltage impressed by the VFD waveform.
Units are said to be designed to run smoother and cooler on inverter power supplies, which can lead to improved system efficiency and reliability. In the past, this product offering was built-to-order, but can now be purchased off-the-shelf.
The motors from Nidec Motor Corporation are NEMA Premium Efficient, and are available in 5 to 300 hp, with 2 and 4 poles (3600 and 1800 rpm), and with frame sizes 184 to 449.