Re: Off grid CNC plasma?
Lets break this down a bit
-CNC table/laptop 4400, About 1KW
-CNC plasma torch flex Cut 80, per the manual @230V, 62 Amps, 14.25KW max
-80 Gal Compressor (make?), About 5KW. Mine draws 23 Amps at full load on the single phase side, it's a true 5HP compressor, ~19 SCFM@90 PSI. Per the Flex Cut 80 manual, 5 SCFM@90 PSI minimum required, but you don't want it running continuous. Air compressors are rated by SCFM/HP, not gallons. I hate what the marketing people have done to the specs. Yes, you could put a 1/2HP compressor pump on a 80 gallon tank, but you would still have a 1/2HP compressor. I have about 260 gallons of air storage capacity, so that must mean I have a huge compressor
-low ambient A/C (Make? cooling approx 400sqft), For the shop? About 1.5KW
-In home refrigerator (make?) 0.25 KW max
-in home freezer (make?) 0.25KW max
So adding all of the above = 20.75 KW, 20750W / 230 V = 90.2 amps. Add 10% for overhead, = 100 A minimum required
Solar/battery/inverter system should handle the refrigerator, freezer, lighting, and small air conditioning and other normal household type loads. But when you kick on a 5HP air compressor and the plasma torch, you are going to need a generator. A 30KW Diesel or propane generator should handle the load. If you can find a low time military surplus unit, those things are tough and are underrated so will output a lot more intermittently.
Add in electric water heating at another 4.5 KW intermittent. My home/shop winter time load is about 35KW max, including electric heat, or about 150 Amps. For summer cooling I only have one small window air conditioner in the bedroom. We don't need it much up here in the northwest.
Jim Dawson
Sandy, Oregon, USA