Sometimes in a particular system, failure of certain parts is usually the cause of downtime. A common solution to this problem is to ensure you have excess spare parts on hand.
Your mechanical counterparts may be doing this with certain bearings, for example. They keep plenty of certain ones on hand, because they are always replacing those. But the real problem is the bearings cannot do the job they are being asked to do. Either a different bearing must be used or the bearing’s job must change (typically, lubrication improvements provide the second solution).
With electrical, the failures seem to happen on a longer timeframe. For example, it may take a year for an incorrectly specified motor to fail and nobody remembers it was replaced a year ago. Your first defense is to track asset history in your CMMS and examine that history before ordering a replacement.
In one installation, the ambient temperature around the motor was barely above the specified limits for its insulation. A long time between failures, but the computerized maintenance management system (CMMS) highlighted that it wasn’t long enough. Upgrading to a higher temperature rating solved the problem.
