Circuit protection can be housed in a small panel or enclosure. Manual shut off of each unit is required. Power ratings of motor-drive packages have been growing slower than first envisioned. At Rockwell Automation, the present top size is 3.75 kW, the a crossover point where heating effects become a substantial design problem. No substantial size increase above 7.5 kW is seen in the near future at Baldor Electric, Lenze, and others.
Few exceptions exist.
A notable exception available now is the Compact Drive product from VEM Motors GmbH. These IMDs range up to 22 kW and include field-oriented and vector control models. Drives for the smaller units come from Danfoss, while Emotron supplies the larger electronics units. Of course, larger power ratings will come as engineers meet design and cost challenges. Above a certain point, however, physical size of hardware makes integration of motors and drives lose all meaning. The more immediate challenge for integrated motor-drive technology is to pare down initial costs and more clearly promote product benefits to potential users.