The RTS GATE-2 inspection is a more thorough inspection of the generator and requires the generator to be disassembled and rotor removed.  This test is frequently performed in conjunction with a turbine major to ensure completion during the outage window.  Besides the GATE-2 testing, RTS can also perform the generator disassembly and reassembly.  The following testing will be performed as base inspection scope during GATE-2 generator testing.

Inspections/Tests Performed

  • Borescope inspection of stator winding, rotor winding and blocking (as accessible), stator core step laminations and fingerplates
  • Insulation resistance of RTD’s, stator winding, and rotor winding
  • Stator Winding Test – Polarization Index (PI), Resistance, DC step voltage test. ELCID, Wedge map
  • Rotor Winding Test – Polarization Index, Resistance, AC Impedance, RSO

Exciter Inspection

  • Visual inspection
  • Insulation resistance tests

Final Report

  • Standardized format provided electronically (cd or electronic mail)
  • Photographs of critical areas in the stator winding, core, and rotor.
  • Dielectric absorption graph and analysis of insulation integrity
  • Summary of all insulation and winding resistance measurements taken.
  • Any anomalies reported immediately with the Final Report submitted within 10 days of inspection

Benefits

  • Reveals pending faults in winding of the rotor and stator
  • Reveals deterioration of coil insulation caused by corona or end winding
  • Reveals possible shorted core laminations
  • Reveals loose slot support system
  • Establishes a “base line” for evaluating future inspections and input for establishing planned major maintenance activities
    • Option – Electrical Isolation
    • RTS can also provide an estimate for the neutral and main leads disconnection prior to electrical testing and reconnect upon completion of testing.