Equipment Condition Assessment for Generators

We conduct generator assessments using a protocol that integrates electrical testing, mechanical inspection, and cooling system evaluation. Stator winding assessment includes insulation resistance testing at specified voltage with temperature correction per IEEE 43, polarization index calculation, power factor (tan delta) testing per IEEE 286 at multiple voltage steps with tip-up analysis, and partial discharge measurement (online or offline based on installation configuration) per IEEE 522 guidelines. Rotor assessment includes field winding insulation resistance, impedance testing (at standstill or at speed depending on rotor type), RSO or flux probe testing for shorted turns detection, retaining ring visual assessment (for cylindrical rotors where accessible), and slip ring or collector condition evaluation. Mechanical assessment includes bearing vibration and temperature, shaft seal condition, foundation and pedestal inspection, and coupling evaluation. Cooling system assessment includes cooler effectiveness measurement, hydrogen purity and pressure (for H2-cooled units), seal oil system operation, and air path condition (for air-cooled units). Stator wedge tightness is assessed through tap testing where outage access permits. Excitation system assessment covers voltage regulator response, exciter condition, and brush gear (for brush-type units). Each subsystem receives a condition grade, and the overall assessment includes insulation remaining life estimation, identified risk items, and prioritized recommendations.