We have a Bently 3300 system monitoring the bearings of a GE 7FA turbine. Lately we have seen intermittent spikes in the vibration readings for both the #1 and #2 turbine bearings. This is occurring while the unit is offline and off turning gear (rotor stationary).
The highest spikes are seen on the x and y of the #2 bearing but we see simultaneous spikes on the #1 bearing.
Because the issue is appearing on several channels, I suspected that the issue has nothing to do with any single probe/prox/cable and more likely was a Mark VI TVIB issue. The card was replaced but the problem did not go away.
Has anyone else seen this issue?