Daun Biru do ‘Bump Test’ on the stator’s winding (stator coils) Generator Unit 2 power plant Ombilin. Bump Test principally aimed at measuring the natural frequency of a structure or sub-structure. The value of the natural frequency is very important to know for sure that resonance will not occur in the structure when the unit is operating.
Testing was conducted using data acquisition modules, vibration sensor (accelerometer), and the impact hammer. The value of the natural frequency of the test results and then compared with the allowed values in IEEE Standard 1665: 2009 Guide for the Rewind of Synchronous Generators. If there is a component that turns the stator coil after the test has a natural frequency value that is not allowed, it is recommended to change the stiffness of the structure.