Here is a pic of the numbers I ran for 20 feet of wire to the converter.
Longer runs will need bigger wire.
I ended up getting a 25 amp DC power supply adjustable from about 4 volts to 16 volts. That was easier than running the 6 gauge wire my 30 foot run required.
It also allows me to use my macerator for friends staying in one of the 2 RV sites I added when they come to stay a while. I have water and electricity at the 2 sites but no sewer.
I do have an one inch diameter 140 foot long underground PVC pipe next to the power pedestal that goes to the sewer clean out in my back yard that I use with the macerator.