Thermal Sensitivity on Turbo Rotor Generator

Dear All

Could you advise me how to test and calculate the thermal vector due to thermal effect vibration on the turbo generator 3000 RPM, 237.5 MVA,

Based on GE paper, I just test for this generator with 2 test step.

Step 1. Make a constant field current with vary MW load

Step 2. Make a constant MW load with vary MVAR

GE specification if thermal vector limit within 2-3 mils or (50.8 - 76) mm, is not consider as a thermal sensitivity.

Based on GE spect, Test step 1, must test up to round cos phi 0.95 leading when test 1, and up to cos phi round 0.78 laging when test 2.

Due to the systems demand during synchronized to systems, we cant test up to 0.95 leading and 0.78 laging, but only cos phi 1 up to 0.8 laging,

as my calculation the thermal vector is 62 micron at bearing 5 and 66 micron at bearing 6.

Could you assisst me what is the conclussion and what is main problems that create vibration, its mechanical or thermal vibration ?

Vibration at cos phi 0.8 = 150 micron at bearing 6, and vibration at bearing 6 60 micron.

Thank you for your advise

Rgds

siswanto