Electric Power Utility Motor Case Study
-
Upload
plato-diaz -
Category
Documents
-
view
35 -
download
0
description
Transcript of Electric Power Utility Motor Case Study
Electric Power Utility Motor Case Study
Electric Power Utility Motor Case StudyDiagnostics & ResolutionPower utility contracted to perform off-line circuit and insulation testing of critical motors during major planned outage. Tests included MCA, IR & overvoltage hipot and impulse.New 4 kV motors are impulse tested to 11.4 kVpk (IEEE). Recommended maintenance test is 9 kVpk. Impulse test discovered a 4 kV pump motor with phase insulation breakdown voltage of 7.2 kVpk. No indication of problem during MCA, IR and hipot tests.Utility opted to start the motor repeatedly to study failure of weak motor insulation system. Insulation failed catastrophically on fifth startup.Motor was rewound during planned shutdownCost of Diagnostics to Utility: