>constantly reposition a vav damper to maintain the airflow setpoint, it means the rest of your system is not setup properly.
Ditto, you have other issues to look at. Also moving an electronic actuator in this manor will reduce its life regardless of the type.
And the word from Mr. Belimo on the life expectancy of the different types…
We test all the actuators the same. The new generation non-spring actuators, i.e., LMBs, are all tested for 100,000 full open-closed cycles and 1,000,000 partial cycles.
I don’t see any noticeable difference between the -3 and –SR.”
That’s lines up with what I have seen over the years. Properly applied and installed they will most likely outlast the controls driving them.