Electric motors tip: Learn about power circuit fault zone

Given the sometimes frenzied movement in the effort to go green, maintenance management may overlook the fact that maintaining reliability can pay dividends toward efficiency while improving the bottom line. Over the next five weeks, this Don't Forget Reliability six-tip series will explore the impact of each of the six fault zones on motor efficiency.

Part Two – Power Circuit
The power circuit fault zone is defined as the system of conductors and connections running from the point of origin of testing to connections at the motor. Any non-symmetric change in the resistive element of a three-phase circuit will create an imbalance in voltage and current. This imbalance results in inefficient circulating currents that produce elevated winding temperature without performing any real work. A study conducted in the mid-1990s determined that more than 46 percent of the faults found in industrial power distribution systems that reduced motor efficiency stemmed from problems within the power circuit.

 
For more information on the effects of reliability on motor efficiency, go to http://www.pdma.com/pdfs/Articles/WhitePapers/ Motor_Efficiency_and_Fault_Zone_Analysis.pdf.

To watch a short discussion on the Power Circuit Fault Zone, go to http://www.pdma.com/webinars/Power_Circuit_Fault_Zone/ powercircuit.html.