New stator laminations — Decision factors

When not detected visually, the iron damage can be identified by performing a "loop test" when the unit is scheduled for rewinding. However, in most of the cases the decision to restack the core is taken after the rotor is out, thus usually extending the duration of the outage. We, at Hydro-Quebec, are interested in finding a method enabling us to assess the state of the iron prior to removal of the rotor, and we want to report our efforts in this direction.