Originally Posted by
percy
The policy is only sensible if there is sufficient lead time to fix the generator that fails before the others fail. If all of these generators are on a rotation cycle it is possible that all will fail together. The generators have been operating for 20 years in imminent failure condition. This alone suggests to me that Meridian don't know why they have kept going for so long, but have apparently been warned that they are in imminent failure condition and chosen to ignore that warning.
Perhaps the people charged with maintaining these generators don't have a full understanding of what is going on inside these generators either? The sure way to settle this is to take one apart and find out. If it all checks out, then the maintenance policy is wrong. If the maintenance policy is wrong it should be changed. If the service engineers are right though, that means Meridian has just been saved an unwelcome outage. Whatever the actual condition of those generators, the only sensible course of action is to pull one out of the loop, strip it down and check.
Whatever the actual condition of those turbines, I might be tempted to leave it if it were say a couple of years or even five years outside its design life. But these things have apparently been running on a knife edge for twenty years! I can't see how anyone could come to the conclusion that just leaving things be is good policy.
SNOOPY