You could be onto something there. Last time I ran the car that died, it was on my testing rig (DCS50), which has no scale selection for lowering the output for N. I just measured 16V RMS. IOW, ~23V, so if the MOV is rated to clamp at 25V, there you go.
A few minutes ago I started to disassemble my other "failed" vacuum car to take measurements. When pulling off the impeller with the little tool it was apparent it had been pushed in enough to not turn freely. Duh. I repositioned the impeller, and whaddayaknow, it works.
In so many words I think you're safe. I, however, need to be mindful of not running the cars directly on the DCS50, to use the track boosters for a more palatable 13V.
