The idea behind Fault Zone Analysis is to ensure that we are looking at each of the critical fault zones to make sure that we are not missing an anomaly that will someday become a serious fault. As a reminder these fault zones are Power Quality, Power Circuit, Insulation, Stator, Rotor, and Air Gap. Not looking at the health of each of these zones on a regular basis will expose your electric motor to an unknown fault and reduced life expectancy. Sometimes we see indications of developing anomalies on more than one zone and think they must be related to a common source. It is possible for a single anomaly to influence more than one fault zone, but we must confirm that with follow-up testing after the repair. Until evidence brings your investigation to a single source, you should act as if multiple fault indications are coming from more than one fault.
To see a case study where two separate faults resulted in a series of motor failures visit the PdMA YouTube Channel at