Overhauling procedure and report of Generator 12 – 12MKA

1. System: GT-12 Main Power Block system

2. Name of Equipment: 12MKA - Generator - 12

3. Observations:

a) Oil found on over hang support at turbine side.b) Insulation damage of the overhang winding found at some places at turbine side.c) Friction dust found on the exciter end.

4. Major Activities:

Preventive Maintenance of the Generator carried out. The major overhauling work carried out as follows:

RSO test done during coasting down at 3000RPM and Impedance test at turning speed.

Brush gear assembly removal and cable connection removal Generator flexi link removal End shield removal Bearing dismantling Removal of Rotor Inspection of Rotor and stator done. DPT done for retaining ring, Bearings and for fan blades Testing of Generator done. Initial report for the testing is attached herewith. Rotor inserted Insulation resistance measurement done at every step during assembly of bearing

pedestal.

5. Corrective actions taken:

a) Oil cleaned with acetone.

Photographs:

b) No severe damage found and varnish sprayed over it so that further damage, if any, can be known in future inspections.

Photographs:

Resources utilized: