For either brand-new motors or those already in service, "best practices" means that informed technicians can make use of the latest diagnostic techniques (vibration analysis, thermography, shaft-voltage testing, etc.) to prevent electrical bearing damage -- either at the very beginning or very quickly thereafter. If done correctly, the work need only be done once.
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.
