ENERGY-TECH • January 2012
At a power generating station in Florida, a severe electrical fault caused such extensive damage to a 40 MW gas turbine-driven generator that a complete replacement of the generator stator was required. An on-site spare generator core was available, but needed the faulted generator’s bearing support brackets to be installed to make it complete. As this combination of bearing support brackets and generator frame would be considered a “mismatch”, it was decided that the position of the bearing supports should be verified to ensure proper centralization of the generator’s field (rotor) relative to the generator core.
The primary objective was to accurately determine the centerline position of the generator core and position the bearing support brackets so that an equal radial air gap between the rotor body and core laminations would be obtained during generator operation.
Exact positioning of the support brackets was accomplished using specialized tooling such as the CENTRALIGN ULTRA laser bore measurement kit and the ROTALIGN ULTRA laser tool from LUDECA.
Read entire article Internal component alignment of 40 MW A.C. generator by our customer Chuck Hildebrand, Dynamic Balancing Company.