Thanks to all for the input.
I’m running lead acid industrial batteries, have a 1/2 go 110 v well pump. Can’t really afford to but 8000$ in new batteries, so I’ll be sticking with 24 volt.
I agree, high frequency units are out for me- I’ll see if an old magnum pae 4024 I have laying around will work ( magnum says “ it’s 10 years old- about their lifetime” - and it didn’t run when I tried it; they indicated that I should hold the reset down for a whole minute to reset, IF it’s resettable. I basically got it free).
I’ll keep looking for a 24 volt low frequency unit. Any recommendations appreciated.
