Sticking to the Fault Zone approach to electric motor troubleshooting we continue this series with Power Circuit. A healthy Power Quality and a healthy motor can still be detrimentally influenced by a defective Power Circuit. Studies found that 47% of reduced efficiency in electric motors results from high resistance connections and other Power Circuit anomalies. Power Circuit anomalies create localized heating and degradation that left alone can result in a catastrophic failure or loss of production. Similar to Power Quality discussed in the last tip, the product of a Power Circuit anomaly is elevated heat. Not only a localized heating as a result of the voltage drop across the high resistance connection, but a stator winding temperature increase as a result of the circulating currents flowing though the motor windings in support of the three-phase imbalance. If the motor is already running fully loaded and at design temperature, running with a Power Circuit anomaly can exceed the design temperature reducing the life expectancy of the motor insulation system. For more examples of Power Circuit anomalies and alarm standards applied to your electric motor reliability visit MCEMAX Fault Zone – Power Circuit on the PdMA YouTube Channel.