Wow that's quite a bit of info to digest. Hijack the thread all you want TConnolly as I'll probably be using your method to control vacuum, sweep gas etc. I'll be tuning this process up for some months.
So as I understand that 1 phase output small motor VFDs exist, but are only for permanent split capacitor motors. Apparently the main reason VFD doesn't work on the single phase motors is due to the starting capacitor.
edit: looks like there is no shortage of small 3 phase vac pumps. I think that's the route I'm headed.
I need to be as precise as possible as I expect to be fractionally distilling if at all possible. I'll be considering the bleeder/butterfly valve control. Perhaps both motor speed control and gas valve control. I did notice that the new line of scroll pumps by edwards (xds6i) have internal drives and are single phase, but they're pretty overpriced.
So as I understand that 1 phase output small motor VFDs exist, but are only for permanent split capacitor motors. Apparently the main reason VFD doesn't work on the single phase motors is due to the starting capacitor.
edit: looks like there is no shortage of small 3 phase vac pumps. I think that's the route I'm headed.
I need to be as precise as possible as I expect to be fractionally distilling if at all possible. I'll be considering the bleeder/butterfly valve control. Perhaps both motor speed control and gas valve control. I did notice that the new line of scroll pumps by edwards (xds6i) have internal drives and are single phase, but they're pretty overpriced.
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