... Both have been working for
6 years, but now the one for the KSR-35 fails
at startup. When I switch on the KSR-35, the
inverter complains that the load is too great
and shuts down.
Your testing tells you that it's the '33 that's the problem. Over time lubricants harden, belts wear, the machine clogs with belt debris and dust. The mechanical load increases, and the motor startup current increases.
To me, it looks like a thorough cleaning and re-lub of the '33 is called for.
tom