All major manufacturers of 3-phase AC induction motors offer "inverter-duty" or "inverter-ready” models, but while these motors have inverter-rated insulation to protect the windings, the bearings--their most vulnerable parts--are too often ignored.

A new preventive maintenance program at a leading New England Ivy League university demonstrates how the push for more sustainable "green" building management has led to a growing awareness of a chronic, widespread problem with HVAC motors—electrical bearing damage and failure.