Originally Posted by Old Fool
Aren't the old Wayne air compressors a mechanical unloader type and do not require high starting currernt
Almost all air compressors (except for the really small "tire pumper" units) have an unloader system otherwise the load would be too high even with a capacitor start, some are mechanical and some are a simple bleed-off system connected to the switch but they all serve the same purpose. An unloaded compressor is still a huge load at start-up due to the mass and inertia encountered when the motor suddenly kicks on and attempts to start all that stationary weight spinning. A simple unassisted motor type phase converter could work for something like a table or band saw or other very light start load if it's sized properly but those capacitor banks are needed for most applications.