...on the bearing housing Lower Guide Bearing (LGB): 2 relative vibration sensors were placed underneath the bearing housing; 2 absolute vibration sensors were placed on the ...
...1 combined thrust and guide generator bearing) – umbrella type V = 13800V I = 8890 A N = 100 rpm (60Hz) Francis turbine Rotor ...
...compared with the measurements on the generator guide bearings namely the Upper Guide Bearing (UGB), Lower Guide Bearing (LGB) and Turbine Guide Bearing ...
...at voltages of about 25% (which should be below the PD Inception Voltage) and 100% of the rated phase-to-ground voltage. There is an important limitation of ...
...the unit’s vertical (axial) direction. One example is given on Fig. 4 (for sensors placed under UGB under the thrust collar). Fig. 4 Sensors under ...
...2.2 COMPARISON OF DATA BEFORE UNIT 2 FAILURE (JULY 2015.) AND AFTER THE OVERHAUL (AUGUST 2016.) For comparison reasons it is interesting to compare vibration ...
...plus a low pass filter) intended to get from 80 pF PD sensors (EMCs), to a measuring range between 100 kHz to 500 kHz . The ...
...because form-wound stators for VS-PWM applications are likely to use mica paper turn insulation, which is very resistant to PD. B. Ground and Phase Insulation In ...
...(acceleration and/or velocity) should be used where displacements are negligible. A better understanding of the nature of winding failures due to endwinding vibration will hopefully lead to ...
...complete blockage of ventilation in air cooled machines. Local overheating is usually caused by design or manufacturing errors, or blockage of radial or axial cooling passages ...