Anyone retrofit a VFD to a single-phase compressor?
I bought an Ingersoll Rand TS4N5 last year to run my airlift well. Basically I am trickling air down a bore hole 24x7 to lift the water out of the well. The compressor only runs about 5 minutes an hour but has 2-3 starts per hour which is apparently too much for the start capacitor because I am now on #3.
It's a single-phase 5hp motor from WEG that came with the compressor and I'm using name-brand (Grainger, not Amazon...) caps so I'm inclined to believe I may just be asking for too many starts from this motor. Wiring is not undersized, and I can't find a relay or any other component that could be going bad.
I'm considering swapping the motor to a 3-phase 5hp and running it with a VFD controller. Advantages being... it would be soft-start with a ramp-up. I may also swap the unloader on the compressor for a solenoid and run that from the VFD controller to shut when the motor is fully spun up.
Has anyone done this? Outcomes? Thoughts? Am I missing anything? A rotary screw would probably be more appropriate for this application but my required cfm is not very high so it would have to be the world's smallest rotary screw to make it cost-efficient in terms of electricity.