This is typically with both constant pressure systems as I have shown before. Dropping alot in amperage is not a good thing as your in the downthrust conditions(you don't want to be in the upthrust condition just as much as the downthrust conditions). Heavy water users I've seen less years.

Pump impellers and the thrust bearing will last longer if you stop abusing them. That's how I'm making my traditional systems last way longer and I know how to keep them out of the upthrust condition with every pump start.