Header Image

GRIP® Level-1

This rotor-in inspection program is designed to fit in a short turbine outage window of 1-2 days (i.e. engine, turbine, or valve borescope inspection).

Features:

  • Turbine Generator Stator (TGS) Inspection:
    • 59-Point Visual and Borescope Inspection (as accessible):
      • TGS Frame (for indications of arcing, oxidation, weld cracks, and other evidence of accelerated aging or damage).
      • TGS Connection Ring Assembly (for indications of mechanical dusting or greasing, loose or missing blocks, corona activity, and other evidence of accelerated aging or damage).
      • TGS End Windings (for indications of contamination, mechanical dusting or greasing, loose or missing blocks, corona activity, and other evidence of accelerated aging or damage).
      • TGS Core Iron (for indications of “fretting”, movement of core bolts, lamination looseness, or any other evidence of accelerated aging or damage).
      • TGS Slot Wedge System (for indications of mechanical dusting or greasing, loose and migrating wedges and/or slot fillers, or any other evidence of accelerated aging or damage).
    • Electrical Testing:
      • Armature Winding Copper Resistance Measurements.
      • Armature Winding Insulation Resistance Testing.
      • Armature Winding Polarization Index Testing.
      • Stator Slot RTD Resistance Measurement.
      • Stator Slot RTD Insulation Resistance Testing.

 

  • Turbine Generator Rotor (TGR) Inspection:
    • 36-Point Visual and Borescope Inspection (as accessible):
      • Retaining Rings (for indications of surface pitting, oxidation, and/or cracks, movement or fretting against fits, electrical arcing, or any other evidence of accelerated aging or damage).
      • Main Field End Windings (for indications of contamination, copper elongation, deformation, or cracking, migration or turn or ground insulation components, or any other evidence of accelerated aging or damage).
      • Rotor Body Wedges (for indications of looseness and/or fretting, electrical arcing, or any other evidence of accelerated aging or damage).
      • Rotor Body Forging (for indications of cracking, arcing, overheating, or any other evidence of accelerated aging or damage).
      • Coupling(s) and Journals (for indications a significant wear, galling, wiping, stress fractures, or any other evidence of accelerated aging or damage).
    • Electrical Testing:
      • Main Field Winding Copper Resistance Measurement.
      • Main Field Winding Insulation Resistance Testing.
      • Main Field Winding Polarization Index Testing.
      • Main Field Winding AC Impedance Testing.

 

  • Turbine Generator Exciter (TGE) Inspection:
    • 14-Point Visual and Borescope Inspection (as accessible):
      • Exciter Windings (for indications of contamination, armature band condition, overheating, or any other evidence of accelerated aging or damage).
      • Collector Ring Assembly or Brushless Exciter Assembly (for indications of contamination, looseness and/or fretting, arcing and/or burning, excessive wear, or any other evidence of accelerated aging or damage).
      • Brush assembly (for indications of contamination, worn insulators, carbon brush condition, or any other evidence of accelerated aging or damage).
    • Electrical Testing:
      • Brushless Exciter Armature Insulation Resistance Testing.
      • Brushless Exciter Stationary Field Insulation Resistance Testing.

Benefits:

  • Reveals pending faults in windings of the stator, rotor and exciter.
  • Reveals deterioration of stator winding insulation caused by partial discharge activity or end winding vibration.
  • Establishes a baseline for evaluating future inspections and input for establishing planned major maintenance activities.
  • Written and digital documentation of critical generator components for planning future maintenance.
Top